• TABLE OF CONTENTS
HIDE
 Front Cover
 Abstract
 Preface
 Summary
 Introduction
 A profile of owner-operators of...
 Policy discussion
 Reference
 Measures of statistical signif...
 Back Cover






Group Title: Agricultural economic report - United States Dept. of Agriculture - no. 513
Title: Assessing erosion on U.S. cropland
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Permanent Link: http://ufdc.ufl.edu/UF00056209/00001
 Material Information
Title: Assessing erosion on U.S. cropland land management and physical features
Series Title: Agricultural economic report
Alternate Title: Assessing erosion on US cropland
Physical Description: iv, 19 p. : ill. ; 28 cm.
Language: English
Creator: Bills, Nelson L
Heimlich, Ralph E
United States -- Dept. of Agriculture. -- Economic Research Service
Publisher: U.S. Dept. of Agriculture, Economic Research Service :
Supt. of Docs., U.S. G.P.O. distributor
Identification Section, National Technical Information Service distributor
Place of Publication: Washington D.C
Springfield Va
Publication Date: 1984
 Subjects
Subject: Soil erosion -- United States   ( lcsh )
Soil conservation -- United States   ( lcsh )
Genre: federal government publication   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 17-18.
Statement of Responsibility: Nelson L. Bills, Ralph E. Heimlich.
General Note: Distributed to depository libraries in microfiche.
General Note: "July 1984"--P. ii
Funding: Electronic resources created as part of a prototype UF Institutional Repository and Faculty Papers project by the University of Florida.
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Bibliographic ID: UF00056209
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 001289183
oclc - 11163559
notis - AGD9857

Table of Contents
    Front Cover
        Page i
    Abstract
        Page ii
    Preface
        Page iii
    Summary
        Page iv
    Introduction
        Page 1
        A new taxonomy of cropland erosion
            Page 1
            Page 2
        Measuring erosion potential
            Page 3
        Cropland erosion and erosion potential
            Page 4
            Page 5
            Page 6
            Page 7
    A profile of owner-operators of erosive soils
        Page 8
        Page 9
        Age
            Page 10
        Size of holding - Net farm income
            Page 11
            Page 12
        Education - Occupation - Type of ownership
            Page 13
            Page 14
    Policy discussion
        Page 15
        Page 16
    Reference
        Page 17
        Page 18
    Measures of statistical significance
        Page 19
    Back Cover
        Page 20
Full Text

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Assessing Erosion on U.S. Cropland: Land Management and Physical Features,
by Nelson L. Bills and Ralph E. Heimlich. Natural Resource Economics Divi-
sion, Economic Research Service, U.S. Department of Agriculture.
Agricultural Economic Report No. 513.




Abstract

The taxonomy of soil erosion presented here delineates land resources with
high potential for erosion control. More than one-third of U.S. cropland is
inherently nonerosive under all management regimes, about half requires
conservation management to keep soil loss within tolerable limits, and the
remaining 8 percent is so erosive that acceptable soil loss rates cannot be
achieved under intensive cultivation. Nationally, no statistically important
relationships were found between characteristics of farm owner-operators and
erosiveness of cropland.

Keywords: Soil erosion, landowners, erosivity, erosion potential, conservation
management, rainfall erosion.




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Washington, D.C. 20250


July 1984












Preface

The persistence of soil erosion problems ha's prompted the Congress to call
for new initiatives to deal with soil loss on cropland. The Secretary of
Agriculture, with authorities granted under the 1977 Soil and Water
Resources Conservation Act (Public Law 95-192), has called for more intense
efforts to target federally sponsored erosion control programs on the Na-
tion's most severe soil loss problems. This study is part of an effort by the
Economic Research Service to examine the consistency between Federal
commodity supply management/income maintenance programs and pro-
grams to control soil loss. Robert Boxley, George Casler, Charles Geisler,
Thomas Hertel, Linda Lee, and Katherine Reichelderfer made helpful com-
ments on an earlier draft of this report.









Contents

Page

Sum m ary .............. ....................... iv

Introduction .................................. 1

A New Taxonomy of Cropland Erosion ............. 1
Measuring Erosion Potential .................. 3
Cropland Erosion and Erosion Potential ........ 4

A Profile of Owner-Operators of Erosive Soils ....... 8
Age .................. ................... 10
Size of Holding .............. ............ 11
Net Farm Income ........... ..............11
Education ................... .............13
Occupation .................................13
Type of Ownership ........................ 13

Policy Discussion ............ ... ............... 15

References................................17


Appendix: Measures of Statistical Significance ...... 19











Summary


Erosion from rainfall causes nearly 100 million acres
of U.S. cropland to erode by more than 5 tons per
acre per year, which may jeopardize productivity.
One-third of this land is so highly erosive that annual
soil loss cannot be reduced to tolerance except under
the most restrictive land management practices.
Most often a change in land use to permanent
vegetative cover will be required. Erosion on the re-
maining two-thirds can be reduced to tolerance with
improved conservation management in crop produc-
tion. This distinction suggests that Federal conserva-
tion efforts should be more accurately targeted to
the inherent, physical characteristics of land used by
farm operators. Such specific targeting of erosion
programs will not disproportionately burden any par-
ticular class of farm operator. At the national level,
characteristics of owner-operators do not appear to
determine erosive management.

Those findings stem from applying a farmland ero-
sion classification that considers both the land's
physical characteristics and the operator's manage-
ment of that land. The classification is designed to
distinguish more clearly between land which can and
cannot be managed to meet a maximum erosion rate
of 5 tons per acre per year. (Soil scientists estimate
that with an erosion rate of 5 tons per acre per year,
the soil can be worked indefinitely with no decline in
productivity.)

Land erosion classes devised for use in this report
are as follows:

Nonerosive, about 37 percent of U.S. cropland
(156 million acres). Its rate of soil erosion will
always be less than 5 tons per acre per year
under any management. Yet, operators of 53
percent of such land, some of them encouraged
by Federal programs, use one or more conserva-
tion practices to control their minimal erosion
problems.

Moderately erosive, but within the tolerable level
about 40 percent of U.S. cropland (171 million
acres). This land has the potential to erode
above the tolerable level of 5 tons per acre per
year; but the operators, by using crop rotations,


contour plowing, minimum tillage, and terraces
keep their erosion below that level.

Moderately erosive, but above the tolerable level,
about 15 percent of U.S. cropland (63 million
acres). With good farm management, this land
could also be worked so that its rate of erosion
is kept below the tolerable 5 tons per acre per
year. But the type of management practiced
causes the topsoil to wash away, in some places
at rates exceeding 25 tons per acre per year.
About half of the operators of such land ap-
parently make no effort to stem their soil losses
by applying conservation practices. This land
and these owners should be targeted for Federal
conservation programs.

Highly erosive, about 8 percent of U.S. cropland
(33 million acres). It will erode by more than 5
tons per acre per year with any kind of cultiva-
tion. The only way to prevent erosion on this
land is to'put it in permanent sod or convert it
to another less intensive land use. More than
two-thirds of this land is planted to row crops,
like corn and soybeans, which cause serious ero-
sion problems. Furthermore, operators of nearly
half of this land have applied no conservation
practices.

Other major findings:

Information aggregated to the national level
shows that the kind of owner-operator makes lit-
tle difference in the land's rate of erosion. While
some earlier studies suggested that age, educa-
tion, type of owner, and so forth contributed to
soil erosion, those studies usually focused on
small geographic areas, failed to account for the
inherent erodibility of the land itself, or both.
For example, while young farmers may have
more severe erosion problems than older
farmers, that is usually because they own
poorer land more susceptible to erosion.

Erosive cropland is concentrated in the Corn
Belt, Southeast, Delta States, Appalachian, and
Northeast regions.











Assessing Erosion on U.S. Cropland:



Land Management

and Physical Features

Nelson L. Bills
Ralph E. Heimlich





Introduction


Erosion from rainfall causes more than 2 billion tons
of soil loss from U.S. cropland each year. Some crop-
land appears to be eroding at such high rates that
the long-term productivity of the land may be jeopar-
dized. Soil losses from cropland also impair water
quality in some areas.

This report investigates relationships between land-
ownership and erosion of cropland caused by rainfall.
The physical parameters of soil loss, as reflected in
the Universal Soil Loss Equation, are manipulated to
place the role of resource management for erosion
control in perspective. Such perspective is often ab-
sent because the now common measure of cropland
erosion (soil loss in tons per acre per year) tends to
mask the role of management. This study clarifies
such relationships by introducing the notion of a
tolerable soil loss applied to the inherent physical
capacity of a soil to erode.

The cropland erosion taxonomy described here is
based on the physical principles underlying accepted
soil loss predictive models and avoids arbitrary and
qualitative designations of erosiveness. By dividing
erosion into its physical and management-related
components, the erosion taxonomy described here
allows analysts and decisionmakers to focus on ero-
sion problems that can be controlled. The taxonomy
can be a useful tool in designing programs or policies
targeted to areas or producers with manageable ero-
sion problems.

The authors are agricultural economists with the U.S. Depart-
ment of Agriculture's Economic Research Service, stationed at
Cornell University, Ithaca, N.Y.


Owners with farmland holdings of 10 or more acres
are described in detail to determine if cropland ero-
sion can be discriminated on the basis of the features
of ownership. This description helps set the stage for
future studies that will compare owners of eroding
cropland with owners who elect to participate in
farm commodity/income maintenance programs.

A New Taxonomy of Cropland Erosion

The NRI estimated soil loss due to erosion using the
Universal Soil Loss Equation (USLE). The USLE is
an erosion model designed to predict average annual
soil losses in runoff from specific field areas in
specified cropping and management systems (33).1
Only erosion from sheet and rill processes occurring
during rainstorms is predicted by the equation. Soil
loss from gullying, road banks, stream banks, or
wind is not accounted for in the equation. The USLE
takes the form:


A = RK(LS)CP


where: A = computed average annual soil loss
per unit area, usually expressed as
tons per acre per year;




1Italicized numbers in parentheses refer to sources cited in
References at end of report.











Assessing Erosion on U.S. Cropland:



Land Management

and Physical Features

Nelson L. Bills
Ralph E. Heimlich





Introduction


Erosion from rainfall causes more than 2 billion tons
of soil loss from U.S. cropland each year. Some crop-
land appears to be eroding at such high rates that
the long-term productivity of the land may be jeopar-
dized. Soil losses from cropland also impair water
quality in some areas.

This report investigates relationships between land-
ownership and erosion of cropland caused by rainfall.
The physical parameters of soil loss, as reflected in
the Universal Soil Loss Equation, are manipulated to
place the role of resource management for erosion
control in perspective. Such perspective is often ab-
sent because the now common measure of cropland
erosion (soil loss in tons per acre per year) tends to
mask the role of management. This study clarifies
such relationships by introducing the notion of a
tolerable soil loss applied to the inherent physical
capacity of a soil to erode.

The cropland erosion taxonomy described here is
based on the physical principles underlying accepted
soil loss predictive models and avoids arbitrary and
qualitative designations of erosiveness. By dividing
erosion into its physical and management-related
components, the erosion taxonomy described here
allows analysts and decisionmakers to focus on ero-
sion problems that can be controlled. The taxonomy
can be a useful tool in designing programs or policies
targeted to areas or producers with manageable ero-
sion problems.

The authors are agricultural economists with the U.S. Depart-
ment of Agriculture's Economic Research Service, stationed at
Cornell University, Ithaca, N.Y.


Owners with farmland holdings of 10 or more acres
are described in detail to determine if cropland ero-
sion can be discriminated on the basis of the features
of ownership. This description helps set the stage for
future studies that will compare owners of eroding
cropland with owners who elect to participate in
farm commodity/income maintenance programs.

A New Taxonomy of Cropland Erosion

The NRI estimated soil loss due to erosion using the
Universal Soil Loss Equation (USLE). The USLE is
an erosion model designed to predict average annual
soil losses in runoff from specific field areas in
specified cropping and management systems (33).1
Only erosion from sheet and rill processes occurring
during rainstorms is predicted by the equation. Soil
loss from gullying, road banks, stream banks, or
wind is not accounted for in the equation. The USLE
takes the form:


A = RK(LS)CP


where: A = computed average annual soil loss
per unit area, usually expressed as
tons per acre per year;




1Italicized numbers in parentheses refer to sources cited in
References at end of report.







A New Taxonomy


R = the rainfall and runoff factor
accounting for the number of rainfall
erosion index units in the average
year;


K = The soil erodibility factor, measur-
ing the soil loss rate per erosion in-
dex unit for the specific soil;


LS = the topographic factor, accounting
for the effects of slope steepness
and length, relative to a 9-percent,
72.6-foot reference slope;


C = the cover and management factor,
accounting for the specific crop and
management relative to tilled con-
tinuous fallow;


P = the support practice factor, account-
ing for the effects of contour plow-
ing, strip-cropping, or terracing rela-
tive to straight-row farming up and
down the slope.


Factor values for the USLE are the results of more
than 10,000 plot years of basic runoff data at 49 loca-


The study is based on land use and
landownership data from the U.S.
Department of Agriculture's
Resource Economics Survey. The
Resource Economics Survey is a
12-part package of interrelated in-
formation on the ownership and use
of land resources in the 48 conter-
minous States and Hawaii.

The first part of the package, the
Soil Conservation Service's (SCS)
1977 National Resource Inventory
(NRI), provided data on the use and
quality of the land. The second part,
the 1978 Landownership Survey
(LOS), provided information on land-
owners.

The 1978 LOS was linked to the
1977 NRI (18-see References). The
NRI was based on a point sample
of the U.S. land area, stratified on
the basis of land units that were
generally 160 acres in size. Soil
Conservation Service field tech-
nicians collected data on each of
three randomly selected points in
each of the 70,000 sampled land
units.

To accomplish the LOS, field tech-
nicians obtained the name and ad-
dress of the owner of the first sam-
ple point in each land unit. About


12,000 of the 70,000 points fell on
land owned by units of government
or on land held in trust for Indian
tribes. These owners were eliminated
from the LOS so that the survey
could be confined to privately
owned land.


Private owners were contacted with
a mail questionnaire. A first and
second mailing, selected personal
interviews, and a telephone follow-
up on nonrespondents ultimately
resulted in collecting usable data
from about 37,000 private land-
owners. Thus, the survey covered 65
percent of all sample points known
to be privately owned.


Land use and landownership data
from the NRI and LOS were merged
for this study. Focusing on sample
points identified as cropland in the
1977 NRI resulted in a data set con-
taining 12,884 records. Included
were points where field technicians
found row crops, close-grown field
crops, summer fallow, rotation hay
or pasture, improved hayland, wild
or native hay, orchards, vineyard,
bush fruit, and other cropland not
harvested or pastured.


To generate regional and national
cropland totals, we expanded the
records in the merged data file by
using the probability of each sam-
ple point's selection in the NRI as a
base. An expansion factor was com-
puted for each respondent given the
probability of selection in the sam-
ple and total acres owned in the
county where the sample point fell.
Thus, each respondent in the merged
set represented a number of owners
equal to the expansion factor.

This technique for expanding point
sample data ensures a correspond-
ence between the physical features
of a cropland point and the charac-
teristics of its owner, but produces
estimates with absolute values that
differ from those reported else-
where for the full 1977 NRI data file.
The difference stems from the fact
that the merged file contains only a
fraction of the 1977 NRI cropland
points (only a fraction of the original
points were included in the 1978
LOS) and the consequent modifica-
tion of the LOS expansion factor.
The 1977 NRI estimate of total U.S.
cropland was 413 million acres.
Techniques used in this study pro-
duce a cropland estimate of 424
million acres, a difference of 11
million acres or 2.7 percent.


Sources of Data







Bills & Heimlich


tions throughout the Nation (33). For the purpose of
the 1977 NRI, technicians in the field characterized
the USLE parameters of each sample point using
guidelines developed by each SCS State office.

This approach to measuring soil loss reflects both
relatively stable physical constraints-rainfall pat-
terns, basic soil properties, and land slope and
shape-and such management factors as crop selec-
tion and cultural practices used on the land. Most of
these management factors are directly under the
farm operator's control and can be changed from
year to year.2

Measuring Erosion Potential

The simultaneous consideration of physical factors
and management factors in the USLE, while produc-
ing useful measurements of annual soil movement,
tends to hamper deliberations over erosion control
policy. Such deliberations focus almost entirely on
the provision of incentives (or disincentives) for crop-
land management; physical features of cropland are
less amenable to manipulation via public policy.
Since soil loss is predicated upon physical considera-
tions, the same level of conservation management
that produces tolerable soil loss on one parcel of land
will result in higher erosion if applied to a relatively
more erosive parcel. Conversely, added precision can
be had by analyzing management decisions after
accounting for the physical features of the cropland
resource.

A traditional approach to controlling for the physical
features of cropland involves classifying soils accord-
ing to erosion hazard. The widely used SCS land
capability class and subclass system identifies ero-
sion hazards with subclass e and the degree of limi-
tation with classes ranging from I (few limitations) to
VII (very severe limitations) (27). However, this
method presents serious problems of interpretation
because subclass e identifies only those soil resources
for which erosion is the dominant limitation. Soils



2In some cases, land management affects the physical con-
straints on soil loss. For example, the principal effect of terraces
and diversions on soil loss is through changes in slope length.
Once a field is terraced, however, the slope length is altered per-
manently or until an equally intensive effort is made to destroy
the terrace.


falling in other subclasses (e.g., cold, wet, or stony
soils) can also have substantial erosion problems. The
1977 NRI showed that 28 percent of cropland erod-
ing above 5 tons per acre per year was on land other
than subclass e (29, pp. 2-34).3

An alternate approach was devised for this study.
The USLE is partitioned into physical and man-
agerial components of soil loss. If a field were con-
tinuously in clean-tilled fallow, the average annual
soil loss would equal the product RKLS (33, p. 40).
This product encompasses the physical properties of
the land; RKLS can be thought of as a reference soil
loss which is management neutral. The product of
the C and P factors reflects the kind of management
applied to the land. The product CP has a theoretical
range from 0 to 1; the amount of erosion increases as
the value of CP increases. However, the maximum
CP recorded in the 1977 NRI was 0.7, and less than 5
percent of inventoried cropland had a combined CP
of more than 0.5.

Partitioning existing erosion rates into physical and
managerial components is the basis of conservation
planning and technical assistance on individual
farms, and has been used in regional studies under
the USDA's Cooperative River Basin Planning Pro-
gram (see, for example, 21). Ervin and Ervin (8) in-
corporated this approach into a study of soil conser-
vation adoption; Ervin (9) used RKLS as a measure
of cropland erosivity in a study of erosion rates on
owned and rented cropland.

This technique for measuring physical erosion poten-
tial can be combined with the idea of a tolerable soil
loss. Soil erosion is a continuous physical process
that can be retarded but not eliminated. Tolerable
soil loss is defined as "the maximum rate of annual
soil erosion that may occur and still permit a high
level of crop productivity to be obtained economi-
cally and indefinitely" (33). Soil loss tolerances
(T-values) range from 2 to 5 tons per acre per year
and were established for U.S. soils at six regional
workshops in 1961 and 1962 (19).



3Limitations of the SCS land capability class-subclass system
are increasingly obvious to policymakers. For example, Cali-
fornia Congressman George E. Brown, Jr., notes that the "old
land class-subclass system lacks internal consistency" and
"...desperately needs to be replaced or upgraded" (2).







A New Taxonomy


Soil loss tolerances are controversial. First, soil loss
tolerances are defined in terms of onsite effects on
productivity and do not consider offsite effects on
sedimentation and water quality. These latter effects
could conceivably reduce tolerable losses. Second,
the rate of soil formation of topsoil (the A-horizon) is
about 1 inch in 30 years, corresponding to a 5-ton
tolerable loss; but the rate of soil formation from
parent material is much slower, corresponding to a
0.5-ton tolerable annual loss (11, 19). Loss of soil
above 0.5 ton per year will eventually reduce avail-
able rooting depth, hence reducing productivity.
Third, gross soil erosion refers only to soil move-
ment on a field and is not equivalent to sediment
yield. Thus, much of the soil lost is redeposited on
the field from which it was generated, increasing soil
depth at the point of deposition.

As soil scientists learn more of the physical and
chemical properties underlying crop productivity
of soils, the effects of continued erosion on pro-
ductivity will become clearer (24, 25, 20). Mathe-
matical modeling of effects of erosion on pro-
ductivity currently being developed will allow a
more precise definition of tolerance levels (32 23, 7).
Until then, existing tolerance levels are the only
reference points in the current debate over soil loss
on the Nation's cropland.

The fundamental distinction to be made between
physical and managerial components of erosion, com-
bined with the notion of a soil loss tolerance, sug-
gests a taxonomy to classify cropland according to
its contribution to the Nation's soil erosion problem.
Such a taxonomy was devised for use in this study
by selecting a soil loss tolerance of 5 tons per acre
per year (29) and partitioning the USLE to control
for the inherent erosivity of the cropland base.




Table 1-A taxonomy of cropland erosivity

Erosion class Definition

Nonerosive RKLS 5 7
Moderately erosive:
Managed below tolerance RKLS > 7; USLE & 5
Managed above tolerance 7 < RKLS < 50; USLE > 5
Highly erosive RKLS > 50; USLE > 5


Under the taxonomy, cropland falls into one of four
categories (table 1). The maximum observed CP com-
bination and simple arithmetic indicate the first clas-
sification in the taxonomy. Since no CP combination
greater than 0.7 was observed, an RKLS less than
7.14 (5 + 0.7) cannot result in an erosion rate
greater than 5 tons per acre per year regardless of
the management applied. Land with RKLS of 7.0 or
less is, therefore, classified nonerosive.

Analogous with the nonerosive category, a class of
cropland can defined with sufficiently high RKLS so
that almost no management except permanent sod
cover yields a tolerable annual erosion rate. An
RKLS value of 50 or more cannot achieve a soil loss
tolerance of 5 tons per acre or less except under the
most restricted rotations and support practices (a CP
value under 0.1); this cropland is classified as highly
erosive.4

Identifying the land that can and cannot be asso-
ciated with tolerable soil losses because of its under-
lying erosivity or lack of it, regardless of manage-
ment, leaves a residual classified as moderately
erosive. Keeping this land within tolerable soil loss
limits depends on the farm operators who manage it.
The portion of the moderately erosive cropland farmed
with CP combinations resulting in erosion rates at or
below the 5-ton limit is categorized as cropland man-
aged below tolerance: The portion that erodes above
5 tons per acre per year because of the relatively
high C factors and lack of support practices employed
is land managed above tolerance.

Cropland Erosion and Erosion Potential

About 3 percent of the Nation's cropland erodes at
annual rates of 25 tons per acre or more (table 2).
Another 3.6 percent of the cropland base erodes at
rates between 14 and 24 tons per acre per year. Both
the 25-ton rate and the 14-ton rate have been defined
as critical erosion levels (21, 28). However, neither
definition is satisfactory because the contributions
made by physical factors and management factors
are not clear when an erosion rate alone is used as a
point of reference.

4No-tillage technology, with adequate residues left on the field,
could potentially reduce this minimum CP value to 0.05 for corn,
grain, and close-grown crops. At present, only about 8.6 million
acres, or 2 percent of U.S. cropland, is planted with no-till sys-
tems (4). The need for occasional turn plowing to reduce weed and
insect problems may still result in rotation CP values over 0.1.







Bills & Heimlich


At the other extreme, 77 percent of U.S. cropland
erodes at tolerable rates of less than 5 tons per acre
per year. Thirty-seven percent of all cropland erodes
at tolerable rates because it is inherently nonerosive
(table 2). For such land, no likely set of management
practices will generate annual soil losses at rates
above tolerance.

On the other hand, virtually all cropland eroding at
an annual rate of 25 tons or more is so inherently
erosive that few, if any, management strategies will
achieve tolerable amounts of annual soil loss. For
such land, erosion control is largely synonymous
with conversion to permanent vegetative cover.
Similarly, about 60 percent of all cropland now erod-
ing at rates between 14 and 24 tons per acre per
year is highly erosive; 17 percent of cropland eroding
in the 5- to 13-ton range is highly erosive as well.
This cropland is not amenable to erosion control
measures to reduce soil loss to tolerance under any
intensive cultivation. Altogether, 8 percent of the
Nation's cropland base is so susceptible to erosion
from rainfall that the production of high-valued row
crops or close-grown crops will raise soil losses
above tolerance under any type of management.

Between these extremes of inherent erosivity and
nonerosivity, soil loss depends upon land manage-
ment. This moderately erosive acreage amounts to
55 percent of the total cropland base (table 2). These
resources, presumably, are the principal point of
reference for current deliberations over publicly
sponsored erosion control policies because of the im-
portance of management in soil loss. Involved are
the selection of crop enterprises, crop rotations,
tillage practices, and the adoption of soil-conserving
land treatments and improvements that allow con-
tinued intensive cropping. Based on the 1977 NRI,
almost 75 percent of the moderately erosive land is
managed below tolerance; well-managed but moder-
ately erosive cropland constitutes 40 percent of total
U.S. cropland. The remaining 15 percent of all U.S.
cropland is moderately erosive and eroding above a
5-ton tolerance. Erosion on this land could be reduced
with improved management practices.

Rainfall on cropland generates more than 1.9 billion
tons of gross soil erosion each year (table 3). Nonero-
sive soils (37 percent of total cropland) account for 7
percent of gross soil erosion. On the other hand,


highly erosive soils generate 44 percent of gross soil
erosion; 30 percent of gross soil erosion is attribut-
able to cropland that is eroding at rates of 25 tons or
more per acre per year. Moderately erosive soils
under conservation management account for 20 per-
cent of total gross soil erosion.

As expected, variations in climate, topography, and
cropping patterns lead to wide regional differences
in cropland erosivity. These regional differences can
be highlighted by summarizing NRI/LOS data for
farm production regions (fig. 1). When compared with
the distribution of all cropland, a relatively large
proportion of nonerosive cropland is found in the
arid or semiarid Mountain and Pacific regions which
account for 30 percent of nonerosive U.S. cropland.
The Northeast, Appalachian, Delta States, and South-
east regions account for a small share of the nonero-
sive category.

An approximately converse relationship exists be-
tween highly erosive and nonerosive cropland.
Regions with relatively low amounts of nonerosive
soils have relatively large amounts of highly erosive
cropland acreage. Compared with the distribution of
all cropland, highly erosive cropland is more



Table 2-Cropland by soil erosion class and rate of
annual soil loss, United States, 1977

Moderately erosive
Managed Managed
below above Highly
Annual soil loss Total Nonerosive tolerance tolerance erosive


Tonslacre/year
Less than 5
5-13
14-24
25 or more
Total


Less than 5
5-13
14-24
25 or more
Total'


1,000 acres


327,813
69,205
15,099
12,229


156,562


171, 251


424,346 156,562 171,251


Percent


77.3 36.9
16.2 -
3.6 -
2.9 -


57,409
5,895
117


-
11,796
9,204
12,112


63,421 33,112



13.5 2.7
1.4 2.2
2.9


100.0 36.9 40.4 14.9 7.8


-Not applicable.
*Less than 0.1 percent.
1Excludes Alaska.







A New Taxonomy


Table 3-Gross soil erosion by soil erosion class and rate of annual soil loss, United States, 1977

Moderately erosive
Managed Managed
below above Highly
Annual soil loss Total Nonerosive tolerance tolerance erosive

Tons/acre/year 1,000 tons

Less than 5 544,016 142,250 401,766 -
5-13 549,229 443,264 105,965
14-24 272,700 101,977 170,723
25 or more 597,690 3,376 594,314

Total1 1,963,635 142,250 401,766 548,617 871,002

Percent

Less than 5 27.7 7.2 20.5 -
5-13 28.0 22.6 5.4
14-24 13.9 5.2 8.7
25 or more 30.4 .1 30.3

Total1 100.0 7.2 20.5 27.9 44.4
-Not applicable.
1Excludes Alaska.










Table 4-Distribution of cropland acreage by soil erosion class and land use, United States, 1977

Moderately erosive
Managed Managed
below above Highly
Land use Total Nonerosive tolerance tolerance erosive

Percent of U.S. acreage

Most erosive:
Corn 22.7 18.8 20.8 29.5 37.5
Soybeans 14.3 8.0 12.6 30.4 22.0
Other row crops 10.8 11.6 7.8 18.3 7.9
Subtotal 47.8 38.4 41.2 78.2 67.4

Less erosive:
Wheat 17.4 20.3 18.9 10.7 8.4
Other close-grown crops 8.0 9.7 8.2 4.5 6.0
Subtotal 25.4 30.0 27.1 15.2 14.4

Other:
Hay 16.5 17.3 22.1 1.0 13.4
Summer fallow 6.3 9.6 5.4 3.4 1.5
All other cropland 4.0 4.7 4.2 2.2 3.3
Subtotal 26.8 31.6 31.7 6.6 18.2

Total1 100.0 100.0 100.0 100.0 100.0
1Excludes Alaska.







Figure 1
Regional Distribution of Cropland Acreage
Erosion by Soil Erosion Class,
United States, 1977


prevalent in the Northeast, Appalachian, and Corn
Belt regions. Also, relatively large amounts of
moderately erosive cropland are managed above
tolerance in the Appalachian, Corn Belt, Delta, and
Southeast regions.

Cropping patterns, as reflected in 1977 NRI data, dif-
fer dramatically among erosion classes. More than
two-thirds of the Nation's most erosive cropland was
used for row crops during the 1977 crop year (table
4). Soil loss measurement is based on a crop rotation,
but row crops, in general, produce higher soil losses
than close-grown or hay crops. Concentration of crop
production in relatively erosive crops is even more
striking on moderately erosive cropland currently
managed above tolerance; more than 80 percent of
this acreage was devoted to corn, soybeans, another
row crops. Conversely, more than a fifth of all
moderately erosive cropland managed at tolerance or
below was in a sod crop in 1977.

Crop selection, however, is only one of several man-
agement factors that influence the rate of soil loss.
Soil loss associated with the production of a crop can
be reduced by the use of land treatment practices.

Several land treatment practices related to rainfall
erosion on cropland were inventoried in the 1977
NRI (see box). Their incidence on cropland was com-
pared for the erosion classes established in this
study (table 5). The proportion of cropland without
conservation practices is virtually identical among
the classes. Operators of 55 percent of U.S. cropland
employ practices designed to reduce soil loss from
rainfall erosion. The most prevalent practice involves
leaving crop residues on the soil. Multiple practices
are also heavily used; 18 percent of all cropland is
treated by more than one conservation practice.

Fifty-three percent of highly erosive cropland has
the benefit of one or more conservation practices.
Multiple practices are employed on 22 percent of this
land; contour farming and contour stripcropping are
used more often on highly erosive land than on non-
erosive land.

The presence of conservation practices on cropland,
regardless of its susceptibility to rainfall erosion,
reflects in large measure the allocation of public
funds for conservation assistance. A 1983 study by


Pacific 5.5


1.7
Mountain 9.5
Mountain 9.5
19.1
4.6
3.8
0.8
Northern Plains 22.4
26.4
23.0
15.1
14.3


Lake States 10.9
14.1
S10.9
5.6
5.9
Northeast 4.2
1.2
6.8

7.7 .
Southern Plains 10.6
10.2
12.2
12.2
1.5
Delta States 4.9
0.4
S 6.4
11.9
5.0


Soil erosion class
SNonerosive
SModerate-managed
below tolerance
7 Moderate-managed
above tolerance
Highly erosive


Southeast 4.1
1.7
S 4.6
7.9
5.2
Appalachian 5.6
118
7.0
7.7
11.8
Corn Belt 22.2
13.9
V 22.1
30.8
45.8
Figures before each bar show regional share of the U.S. total in each
erosion class.
Figures above bars show each region's share of the U.S.
cropland acreage.







Profile of Owner-Operators


the U.S. General Accounting Office, for example, con-
cluded that Federal funds have historically been dis-
tributed in a way that is only indirectly linked to the
Nation's soil loss problem (31). Procedures for admin-
istering such programs contrast sharply with more
recent USDA initiatives to target Federal funds and
technical assistance to more severe erosion prob-
lems.


A Profile of Owner-Operators of Erosive Soils

Merged data from the 1977 NRI and the 1978 LOS
provide unprecedented information on the relation
between soil erosion and landownership. The NRI is
the first effort to make quantitative estimates of
rainfall erosion for the entire Nation. Previous na-
tional inventories, conducted in 1958 and 1967 by the
USDA, were restricted to a qualitative assessment
of conservation treatment needs. USDA conducted
the first national study of farmland ownership in
1946 (13); but unlike the 1978 LOS, the 1946 survey
procedures did not permit ownership to be associated
with soil loss on cropland.

Data from the 1978 LOS were used to describe who
manages U.S. cropland. This description is possible
because ownership data from the LOS were asso-
ciated with each cropland point. Two major problems
are encountered, however. First, much cropland is


rented. Management decisions on rented land pre-
sumably involve both the landowner and the renter.
Second, some cropland points probably are asso-
ciated with ownerships that are too small to coincide
with the conventional (Census Bureau) definition of a
farm.5 This stems from the fact that LOS
respondents were not asked to value the production
on land they categorized as "land in farms and
ranches." LOS describes owners rather than farm
operators.

The ownership-farm operation problem cannot be
overcome. LOS describes owners of land rather than
renters of land. Consequently, the description of
landowners must be confined to those owners who
could be identified as the operator of the cropland
point sampled in the 1977 NRI. Fortunately, such
owner-operators use about 50 percent of U.S. crop-
land (table 6). About one-third of all cropland is
owned by owners who have no farming operations
but rent cropland to others (landlords). A smaller
fraction of land is held by owners who rent land to
others and also operate land as a farm (operator-
landlords). The owners of 7 percent of all cropland
did not report on tenure status. When owned by a
landlord, the features of the operator of the cropland
included in the NRI sample cannot be determined.

5The Census definition of a farm is a place with farm produc-
tion valued at $1,000 or more during the census year (30).


Table 5-Distribution of cropland acreage by soil erosion class and conservation practice, United States, 1977

Moderately erosive
Managed Managed
Conservation below above Highly
practice Total Nonerosive tolerance tolerance erosive

Percent of acreage


No practice
Grassed waterway
Contour
Contour strip
Terraces
Diversions
Residue use
Minimum tillage
Combinations of practices:
Minimum tillage and residue
All other combinations

Total1
'Excludes Alaska.


45.2
2.3
2.3
.7
.6
.2
28.2
2.2

7.1
11.2

100.0


47.1
.9
.5
.3
.2
.2
34.4
2.9

8.5
5.0

100.0


43.0
2.3
3.2
1.3
.6
.2
25.1
1.7

6.9
15.7

100.0


100.0


100.0






Bills & Heimlich


Conservation Practices*


Grassed Waterway-A natural or
constructed waterway or outlet,
shaped or graded, and established
in suitable vegetation for the safe
disposal of runoff. (412)

Contour Stripcropping-Growing
crops in a systematic arrangement
of strips or bands on the contour to
reduce water erosion. The crops are
arranged so that a strip of grass or
close-growing crops is alternated
with a strip of clean-tilled crop or
fallow or a strip of grass is alter-


nated with a close-growing crop.
(585-A)

Crop Residue Use-Using plant
residues to protect cultivated fields
during critical erosion periods.
(344-A)

Contour Farming-Farming sloping
land so that plowing, preparing
land, planting, and cultivating are
done on the contour. (This includes
following established grades of ter-
races or diversions.) (330-A)


Terrace-An earth embankment,
channel, or a combination ridge and
channel constructed across the
slope. (600)

Diversion-A channel with a sup-
porting ridge on the lower side con-
structed across the slope. (362)

Minimum Tillage-Limiting the
number of cultural operations to
those that are properly timed and
essential to produce a crop and pre-
vent soil damage. (478)


*As defined in National Handbook of Conservation
Practices. Numbers in parentheses are the conservation
practice codes defining standards for the practice.


Similarly, the operator of cropland owned by an
operator-landlord cannot be described because the
NRI sample point may have fallen on cropland
operated by the owner described in the LOS or on
cropland that the owner rented to another farm
operator.

There is no satisfactory way to adjust LOS data to
overcome the problem of farm definition. For this
study, we discarded cropland points associated with
landholdings of less than 10 acres under the assump-
tion that few owner-operators with such small acre-
ages meet the commonly used definition of a farm.
This procedure further confined the scope of the
study. Owner-operators with holdings of 10 or more
acres became the focus of the ownership description;
these owners account for 210.9 million acres of U.S.
cropland.

Owner attributes described are type of ownership,
size of farmland holding, net farm income, age, occu-
pation, and education. Information on type of owner-
ship and size of holding is available for all ownership
units; information on personal owner characteristics
is not available for ownership units organized as
large corporations, unsettled estates, or other
institutions.


These owner characteristics were selected because
of their assumed relevance to current discussions
about the consistency of Federal program with
regard to soil erosion. To increase precision, we
tested for the statistical significance of differences in
landowner characteristics among erosion classes (see
appendix). The tests show that none of the differences
observed is statistically significant at this national
level of aggregation.

Where possible, previous studies of the relationships
between operator characteristics and soil erosion are
discussed in light of our findings. Direct comparisons
are limited because, in general, the available litera-

Table 6-Cropland holdings by land tenure, United
States, 1978

Land tenure Cropland

1,000acres Percent

Operator 211,749 49.9
Landlord 140,459 33.1
Operator-landlord 39,888 9.4
No response 32,250 7.6
Total' 424,346 100.0
'Excludes Alaska.






Profile of Owner-Operators


ture deals with perceptions of erosion problems or
adoption of conservation practices. Few studies
relate operator characteristics directly to objective
measures of erosion. Use of subjective erosion
measures, combined with a focus on small areas, has
made much previous research inconclusive, if not in-
consistent, in regard to the role of ownership charac-
teristics in erosion control (16).


Age

The structure of farmland ownership-its acquisi-
tion, use, and disposal-is conditioned by the life
cycle of farmland owners. Older individuals have con-
stituted the major class of owners for many years
(10). Farmland is an asset, and aging is generally
associated with the accumulation of capital assets.
Inheritance is an important route to farmland
ownership, but more than three-quarters of all
owners acquired their farmland via purchases in the
land market (5). Many farmers continue to participate
in farm operation and ownership well beyond nor-
mal retirement age. Finally, as the cost of starting a
farm business (including the purchase of farmland)


has increased, younger people have more often
entered nonfarm occupations or began farming as
renters.

Most owner-operators are 50 years old or older (table
7). A relatively high proportion of owners between
35 and 49 years old operate nonerosive cropland; few
owners of nonerosive cropland are over 65 years old.
By contrast, the age distribution of owners with
highly erosive cropland is comparable to the age
distribution of owners of all cropland. There is no
appreciable difference in the age distribution of
owners with moderately erosive cropland, however,
regardless of the level of conservation management.

This result runs counter to some hypotheses con-
cerning age and soil erosion. One can argue that age
is negatively associated with erosion because the
older farmers will possess better land resources, will
have experienced the effects of erosion, or will have
greater financial resources to deal with erosion prob-
lems on their land. Hoover and Wiitala (12) found
that a significantly higher proportion of younger
farmers in a Nebraska watershed perceived an ero-
sion problem than did older farmers, although fewer


Table 7-Owner-operators by age and soil erosion class, United States, 1978

Moderately erosive
Managed Managed
below above Highly
Age Total Nonerosive tolerance tolerance erosive

1,000 owners
Under 35 years 112.9 32.0 51.2 17.8 11.9
35-49 years 301.1 104.0 125.5 38.9 32.7
50-64 years 390.6 123.4 174.9 54.9 37.4
Over 65 years 148.8 31.3 73.1 29.6 14.8
Total reporting age 953.4 290.7 424.7 141.2 96.8
Age not reported 41.8 15.3 16.7 7.0 2.8
Corporations, unsettled estates, and other institutions 22.5 6.6 9.3 3.7 2.9
Total' 1,017.7 312.6 450.7 151.9 102.5

Percent2
Under 35 years 11.8 11.0 12.1 12.6 12.3
35-49 years 31.6 35.8 29.5 27.5 33.8
50-64 years 41.0 42.4 41.2 38.9 38.6
Over 65 years 15.6 10.8 17.2 21.0 15.3
Total' 100.0 100.0 100.0 100.0 100.0
1Excludes Alaska.
2Percentage of owners for which age of owner was reported.






Bills & Heimlich


young farmers participated in SCS programs. Ervin
and Ervin, however, did not find age significant in
explaining perception of erosion problems in
Missouri (8).

The mean age of operators adopting conservation or
minimum tillage in two Iowa studies was signifi-
cantly lower than that of later adopters or non-
adopters (3, 14). More generally, Ervin and Ervin
found that younger, less experienced operators
adopted higher numbers of conservation practices
and exerted more conservation effort than did older,
more experienced farmers (8). Younger operators
judged more conservation practices to be profitable
than did older farmers. Baron found a strong nega-
tive correlation between age and investment in con-
servation expenditures for operators in the Southern
Plains, Delta, Corn Belt, and Northern Plains, based
on 1978 LOS data (1). However, neither Earle et aL
nor Hoover and Wiitala found age significant in
explaining adoption of soil conservation practices
(6, 12).



Size of Holding

Farmland has always traded freely in the land
market and passed from one generation to another
via inheritance. These avenues for land transfer,
coupled with new technology in livestock and crop
production and population growth, have presented
owners with opportunities to consolidate or sub-
divide their farmland holdings.

The size distribution of holdings for owner-operators
is shown in table 8. Owner-operators of highly ero-
sive cropland have proportionally more small hold-
ings (under 100 acres). A higher proportion of owners
in the nonerosive class have larger holdings (over
260 acres) than for other erosion classes. Owners of
moderately erosive cropland managed above toler-
ance have the highest proportion of holdings in the
middle range (100-259 acres).

As with age, our findings related to farm size do not
necessarily contradict the divergent soil conservation
literature. Ervin found that farm size was not signifi-
cant in explaining observed erosion rates on rented
cropland in Missouri (9). Several other studies found
that farm size is positively associated with adoption


of reduced tillage technology (17, 14, 3). Earle et at
found that farm size was the most effective variable
in discriminating between adopters and nonadopters
of conservation measures in Australia (6). Farm size
was positively and significantly related to conserva-
tion investment in four midwestern farm regions (1).
Conversely, Hoover and Wiitala concluded that farm
size was not significant in explaining perception of
erosion problems or adoption of erosion control prac-
tices (12). Relationships between farm size and adop-
tion of reduced tillage, on the other hand, may have
more to do with efforts to control production costs
than to control erosion (16).

On balance, adoption of conservation practices may
be related to farm size simply because a larger farm
has more varied erosion problems, which promote
the use of a wide range of control techniques. The
connection between farm size and conservation effort
is not convincingly shown in the literature. After
controlling for erosion potential of the land, our
study suggests that farm size is not a significant fac-
tor in soil loss from erosion caused by rainfall.


Net Farm Income

Farmland owners who participated in the 1978 LOS
were asked to report their 1977 net farm income
(table 9). However, such information is difficult to
interpret (5). First, many landowners consider
income from farming to be privileged information. A
relatively large fraction of all owners did not
respond to the income question. Second, the income
question was asked for a specific year (1977). Since
net farm income can vary greatly from year to year,
the average or typical net income might diverge sub-
stantially from that reported for the survey year.
Finally, net income can be computed in a number of
ways, but LOS respondents did not receive specific
instructions on how the calculation should be made.
This problem is particularly acute for a farm opera-
tion because the operator and family often supply
capital, labor, and management services to the busi-
ness. Implicit, and often arbitrary, charges for any
capital, labor, and management services supplied by
the farm family can be included in a calculation of
net farm income for some purposes but excluded for
others. It seems unlikely that all respondents, with-
out specific directions, handled such calculations in a
consistent fashion.







Profile of Owner-Operators


Table 8-Owner-operators by size of holding and soil erosion class, United States, 1978

Moderately erosive
Managed Managed
below above Highly
Size gf holding Total Nonerosive tolerance tolerance erosive

1,000 owners
10-99 acres 468.9 130.3 214.6 71.5 52.5
100-259 acres 345.5 102.6 152.7 54.8 35.4
Over 260 acres 203.3 79.7 83.4 25.6 14.6

Total' 1,017.7 312.6 450.7 151.9 102.5

Percent
10-99 acres 46.1 41.7 47.6 47.1 51.2
100-259 acres 33.9 32.8 33.9 36.1 34.6
Over 260 acres 20.0 25.5 18.5 16.8 14.2

Total1 100.0 100.0 100.0 100.0 100.0
1Excludes Alaska.








Table 9-Owner-operators by net farm income and soil erosion class, United States, 1977

Moderately erosive
Managed Managed
below above Highly
Net farm income Total Nonerosive tolerance tolerance erosive

1,000 owners
None 69.8 20.3 30.8 11.7 7.0
Loss 171.1 51.3 74.0 28.6 17.2
$0-$6,999 300.9 87.8 138.7 42.4 32.0
$7,000-$19,999 189.7 60.4 81.5 26.3 21.5
$20,000 or more 95.2 32.9 44.3 11.9 6.1

Total reporting income 826.7 252.7 369.3 120.9 83.8

Income not reported 168.5 53.3 72.1 27.3 15.8
Corporations, unsettled estates, and other institutions 22.5 6.6 9.3 3.7 2.9

Total' 1,017.7 312.6 450.7 151.9 102.5

Percent2
None 8.4 8.0 8.3 9.7 8.3
Loss 20.7 20.3 20.0 23.7 20.5
$0-$6,999 36.4 34.8 37.6 35.1 38.3
$7,000-$19,999 23.0 23.9 22.1 21.7 25.6
$20,000 or more 11.5 13.0 12.0 9.8 7.3

Total' 100.0 100.0 100.0 100.0 100.0
'Excludes Alaska.
2Percentage of owners for which net farm income was reported.







Bills & Heimlich


With these rather serious reservations in mind, one
can associate farm income with soil erosion class.
Results show a remarkably similar income distribu-
tion among the classes (table 9). Just under 30 per-
cent of all owners reporting an income, regardless of
soil erosivity, indicated that they realized no net
farm income or incurred a loss during calendar 1977.
The proportion of owners with relatively high net in-
comes-$20,000 or more-tends to be lower for crop-
land eroding at rates above tolerance than for all
cropland. These differences, however, do not appear
to be very large.

Prior evidence on the relationship between farm in-
come and soil erosion is not always consistent with
our findings. Lee found that mean erosion rates did
not differ among income classes at the national or
regional levels until tenure was taken into account
(15). National mean erosion rates were significantly
lower for owner-operators with net farm income be-
tween $3,000 and $50,000 than for those in lower or
higher income classes. These differences were also
significant in the Corn Belt and Southern Plains.
Baron found a positive, but weak, relationship
between net farm income and conservation invest-
ment (1). He argued that income did not pose an im-
portant constraint on investments in conservation
structures.

On the other hand, studies related to the adoption of
conservation practices and reduced tillage have often
stressed the importance of income as an explanatory
variable. For example, Bultena-Hoiberg and Korsching
et at found significantly higher mean gross farm
income levels for conservation tillage adopters than
for nonadopters 3, 14). Earle et aL also found that
with declining farm income, adoption of conservation
practices likewise declined (6).


Education

Owners of highly erosive and moderately erosive
cropland managed above tolerance are slightly less
educated than owners of cropland in other erosion
classes (table 10). A slightly higher percentage of
owners of nonerosive cropland are college graduates
than are owners of cropland in other erosion classes.
A higher proportion of owners of highly erosive
cropland have elementary educations than owners of
land in other erosion classes.


Education is often thought to be negatively related to
erosion and positively related to perception of ero-
sion problems and adoption of soil conservation prac-
tices. The literature consistently supports this
hypothesis, although the strength of the reported
relationships varies. As before, few studies investi-
gated the direct relationship between educational
attainment of landowners and erosion rate. Ervin
and Ervin reported that education was positively
and significantly associated with all three of their
dependent variables: perception of erosion problems,
number of erosion control practices installed, and soil
conservation effort (8). Baron found that education
was positively and significantly related to conserva-
tion investment in the Delta, Corn Belt, and North-
ern Plains regions but was insignificant in the South-
ern Plains (1).

Research on conservation practice adoption generally
provides only modest support for the education
hypothesis. Earle et al included educational level as
the last independent variable in a discriminant
analysis between adopters and nonadopters because
of its modest effect as a discriminator (6). Korsching
et aL found the mean years of education for
minimum tillage adopters to be only 0.7 year higher
than for nonadopters, a difference not statistically
significant (14). Bultena and Hoiberg found that the
percentage of operators with post high school educa-
tion was higher for early and late adopters of conser-
vation tillage than for nonadopters (3). The differ-
ence was significant only between late adopters and
nonadopters, however.

Occupation

Most owner-operators listed their principal occupa-
tion as farming (table 11). The highest proportion of
farmers and lowest proportion of retired owners
have land in the nonerosive class. Few important
differences in the proportion of blue-collar workers
and white-collar workers are observed among the
erosion classes.

Type of Ownership

Most owner-operated farms, regardless of soil ero-
sion class, are held by individuals or families (table
12). Differences in ownership type among erosion
classes are small.







Profile of Owner-Operators


Table 10-Owner-operators by education level and soil erosion class, United States, 1978

Moderately erosive
Managed Managed
below above Highly
Education level Total Nonerosive tolerance tolerance erosive

1,000 owners

Elementary 204.8 49.9 101.2 28.2 25.5
High school 497.2 156.9 203.9 82.3 54.1
Some college 121.8 39.5 58.3 14.9 9.1
College graduate 106.0 39.0 48.0 12.8 6.2

Total reporting education 929.8 285.3 411.4 138.2 94.9

No response to education 65.4 20.7 30.0 10.0 4.7
Corporations, unsettled estates, and other institutions 22.5 6.6 9.3 3.7 2.9

Total1 1,017.7 312.6 450.7 151.9 102.5

Percent2

Elementary 22.0 17.5 24.6 20.4 26.9
High school 53.5 55.0 49.6 59.5 57.0
Some college 13.1 13.8 14.2 10.8 9.6
College graduate 11.4 13.7 11.6 9.3 6.5

Totally 100.0 100.0 100.0 100.0 100.0
1Excludes Alaska. 2Percentage of owners for which education level was reported.


Table 11-Owner-operators by principal occupation and soil erosion class, United States, 1978

Moderately erosive
Managed Managed
below above Highly
Principal occupation Total Nonerosive tolerance tolerance erosive

1,000 owners

White collar 95.5 27.2 50.6 11.1 6.6
Blue collar 131.2 39.3 54.2 23.5 14.2
Farmer 650.4 212.1 279.6 93.4 65.3
Retired 62.3 8.1 32.7 14.0 7.5
Other 15.9 6.4 6.0 1.8 1.7

Total reporting occupation 955.3 293.1 423.1 143.8 95.3

No response to occupation 39.9 12.9 18.3 4.4 4,3
Corporations, unsettled estates, and other institutions 22.5 6.6 9.3 3.7 2.9

Total1 1,017.7 312.6 450.7 151.9 102.5

Percent2

White collar 10.0 9.3 12.0 7.7 6.9
Blue collar 13.7 13.4 12.8 16.3 14.9
Farmer 68.1 72.3 66.1 65.0 68.5
Retired 6.5 2.8 7.7 9.7 7.9
Other 1.7 2.2 1.4 1.3 1.8

Total1 100.0 100.0 100.0 100.0 100.0
'Excludes Alaska. 2Percentage of owners for which occupation was reported.






Bills & Helmlich


Few studies examined ownership as a variable asso-
ciated with erosion problems. An exception was Lee
who found no significant differences between erosion
rates for ownership types at the national level, but
did find differences in four regions (15). In the North-
east, Southeast, and Mountain regions, family-owned
land had erosion rates between 1.6 and 8.6 tons per
acre per year higher than the mean erosion rate of
land owned by nonfamily corporations. Nonfamily
partnerships in the Lake States had erosion rates 6.5
tons higher than nonfamily corporations.

Lee concluded in a separate analysis that differences
in erosion rates by type of owner could be attributed
to higher percentages of erosion-prone land in the
family ownerships. In the Southeast, family owners
had more erosive land than nonfamily owners and
used fewer erosion control practices. Since the ero-
sion taxonomy used in this report controls for both
inherent erosivity and management, however, the ap-
parent relationships found by Lee do not manifest
themselves in data aggregated to the national level.

Korsching et aL found a significant difference in an
index of business complexity (e.g., sole proprietor =
1.0 and corporation = 5.0) between adopters and


nonadopters of minimum tillage (14). They conclude
that more innovative operators are more likely to
adopt both minimum tillage technology and more
complex business organizations. Hoover and Wiitala,
on the other hand, found type of ownership to be in-
significant either in discriminating between operators
with differing erosion perceptions or in explaining
differences in adoption of conservation practices (12).

Policy Discussion

Application of the soil erosion taxonomy described
here to the problem of erosion caused by rainfall on
cropland adds precision to discussions of Federal soil
conservation programs and policies. If confining an-
nal soil loss to a tolerance level is the policy goal,
public programs must be more accurately targeted
to the physical properties of the resources used by
farm operators. Much cropland is simply not vulner-
able to substantial soil loss from rainfall. On the
other hand, 8 percent of U.S. cropland is so vulner-
able to rainfall erosion that conventional soil conser-
vation techniques-selection of rotations, tillage
practices, conservation treatments, and the like-will
not achieve a tolerable annual soil loss. Appropriate
management of these highly erosive resources im-


Table 12-Owner-operators by type of ownership and soil erosion class, United States, 1978
Moderately erosive
Managed Managed
below above Highly
Type of ownership Total Nonerosive tolerance tolerance erosive
1,000 owners

Sole proprietor 364.7 107.6 163.8 59.4 33.9
Family ownership 544.6 171.3 237.2 78.1 58.0
Partnership 70.4 23.0 29.4 10.7 7.3
Corporation 28.1 7.9 15.7 1.6 2.9
Other 9.9 2.8 4.6 2.1 .4
Total1 1,017.7 312.6 450.7 151.9 102.5
Percent

Sole proprietor 35.8 34.0 36.3 39.1 .33.1
Family ownership 53.5 54.8 52.7 51.4 56.6
Partnership 6.9 7.4 6.5 7.0 7.1
Corporation 2.8 2.5 3.5 1.1 2.8
Other 1.0 .9 1.0 1.4 .4
Total' 100.0 100.0 100.0 100.0 100.0
1Excludes Alaska.






Policy Discussion


plies changing land use from cropland to permanent
vegetative cover.

The residual, labeled "moderately erosive" cropland
in this study, makes up 55 percent of the total crop-
land base. This land has the physical potential to
erode at excessive rates, but actual soil loss depends
on the management applied by the operator each
year. These resources and the individuals who own
or operate them for farming purposes presumably
are a principal focus for government erosion control
policies because such policies focus on, or indirectly
affect, cropland management. Questions related to
the effects of Federal commodity/income maintenance
programs on soil loss are particularly relevant to
this land because of the paramount role management
plays in acceptable (or unacceptable) soil loss rates.

Our taxonomy of erosive cropland provides a firmer
conceptual basis for targeting soil conservation ef-
forts. Public programs to control soil erosion should
focus on land with the following criteria:

Productive soil.

Manageable erosion problems.

Impairment of productive capacity if erosion is
not remedied.

If any of these criteria are missing from a particular
field, that land should be accorded a lower priority
for erosion treatment.

To clarify the relationships between land manage-
ment considerations and landownership, we compared
the characteristics of owner-operators of cropland
with their land's erosion class. We selected size of
holding, type of ownership (individual, partnership,
or corporate), net farm income, age, occupation, and
education as characteristics for study because of the
emphasis placed upon them in recent soil erosion
literature. Our study, built on comprehensive data for
the entire Nation, provides an opportunity to amplify
on the importance of these attributes in soil erosion
because much existing evidence is anecdotal or
limited to case studies of local situations.

We found no statistically significant associations be-
tween those features of owners and soil loss on crop-


land. We did find that size of holding tends to vary
inversely with the degree of soil erosivity. Relatively
larger numbers of owners with highly erosive crop-
land hold farmland in smaller parcels, while rela-
tively large numbers of owners of nonerosive crop-
land hold farmland in larger parcels.

No important differences were observed between
owners organized as corporations, partnerships, joint
owners with their spouses, or sole proprietors.
Similarly, few contrasts could be drawn between
owners with different occupations or between
owners who realized varying amounts of net farm in-
come during the 1977 crop year. Only small dif-
ferences were observed in the age and educational
levels of owner-operators of cropland in each ero-
sion class.

On balance, therefore, our study provides little sup-
port for the idea that Federal programs need to be
tailored to specific types of farmland owners. There
are few demonstrable relationships at this highly
aggregated level of analysis between the characteris-
tics of owner-operators and soil loss. Conversely, our
findings suggest that policies targeting on land of
moderate to high erosion potential need not single
out certain classes of farm operators for special con-
sideration. Thus, the burden of more intense efforts
to take remedial public action probably will not fall
disproportionately on any one class of farm operators.

This finding is contrary to much (but not all) of the
accumulated literature on the role of ownership in
the generation of soil loss on cropland. However, an
important amount of this literature is either without
empirical support or is based on case studies of small
watersheds. The latter studies demonstrate the ef-
fects of ownership on soil loss in local situations but
are too fragmentary to support broader public policy
decisions.

Regardless of geographical scope, our study does
demonstrate the importance of taking the erosion
potential of cropland into account before inquiring in-
to whether the characteristics of farm operators,
their attitudes, and behavior affect soil loss. The pro-
cedures devised for this study appear to merit fur-
ther application in future studies of the U.S. erosion
control problem.






Bills & Helmlich


References

1. Baron, D. "Landownership Characteristics and
Investment in Soil Conservation," Staff Report
AGES810911. U.S. Department of Agriculture,
Economics and Statistics Service, September
1981.

2. Brown, G. E., Jr. "Information Management for
Conservation Decisions." Journal of Soil and
Water Conservation, Vol. 38, No. 6, November-
December 1983, pp. 451-454.

3. Bultena, G. L., and E. O. Hoiberg. "Factors
Affecting Farmers' Adoption of Conservation
Tillage." Journal of Soil and Water Conserva-
tion, Vol. 38, No. 3, May-June 1983, pp. 281-283.

4. Christensen, L. A., and R. S. Magleby. "Conser-
vation Tillage Use." Journal of Soil and Water
Conservation, Vol. 38, No. 3, May-June 1983,
pp. 156-157.

5. Daugherty, A. B., and R. C. Otte. "Farmland
Ownership in the United States," Staff Report
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Economic Research Service, June 1983.

6. Earle, T. R., C. W. Rose, and A. A. Brownlea.
"Socio-Economic Predictors of Intention Towards
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7. Eleveld, B., G. V. Johnson, and R. G. Dumsday.
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pp. 387-389.

8. Ervin, C. A., and D. E. Ervin. "Factors Affecting
the Use of Soil Conservation Practices: Hypothe-
ses, Evidence and Policy Implication." Land Eco-
nomics, Vol. 58, No. 3, August 1982, pp. 277-292.

9. Ervin, David E. "Soil Erosion Control on Owner-
Operated and Rented Cropland." Journal of Soil
and Water Conservation, Vol. 37, No. 5,
September-October 1982, pp. 285-287.


10. Geisler, C. C., N. L. Bills, J. R. Kloppenburg, Jr.,
and W. F. Waters. "The Structure of Agricultural
Landownership in the United States, 1946 and
1978." Search: Agriculture, No. 26, Agricultural
Experiment Station, Cornell University, Ithaca,
N.Y., 1983.

11. Hall, G. F., R. B. Daniels, and J. E. Foss. "Soil
Formation and Renewal Rates in the U.S." in
Determinants of Soil Loss Tolerances, American
Society of Agronomy, 1979.

12. Hoover, H., and M. Wiitala. "Operator and Land-
lord Participation in Soil Erosion Control in the
Maple Creek Watershed in Northeast Nebraska,"
Staff Report NRED 80-4. U.S. Department of
Agriculture, Economics, Statistics, and Coopera-
tives Service, March 1980.

13. Inman, B., and W. Fippin. Farm Land Ownership
in the United States, Misc. Pub. 699. U.S.
Department of Agriculture, Bureau of Agricul-
tural Economics, 1949.

14. Korsching, P. F., C. W. Stofferahn, P. J. Nowak,
and D. J. Wagener. "Adopter Characteristics and
Adoption Patterns of Minimum Tillage: Implica-
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September-October, 1983, pp. 428-430.

15. Lee, L. K., "The Impact of Landownership Fac-
tors on Soil Conservation." American Journal of
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1980, pp. 1070-1076.


16. "Implications of Land Tenure Patterns
for the Conservation of Soil and Water." Pre-
sented at Economic, Legal and Policy Frontiers
in Natural Resource Economics, symposium
honoring John F. Timmons, Iowa State Univer-
sity, October 28, 1983.


17. and W. H. Stewart. "Landownership
and the Adoption of Minimum Tillage." Ameri-
can Journal of Agricultural Economics, Vol. 65,
No. 2, May 1983, pp. 256-264.






References


18. Lewis, J. A. Landownership in the United
States, 1978, AIB-435. U.S. Department of Agri-
culture, Economics, Statistics, and Cooperatives
Service, April 1980.

19. McCormack, D. E., K. K. Young, and L. W. Kim-
berlin. "Current Criteria for Determining Soil
Loss Tolerance." In Determinants of Soil Loss
Tolerance, American Society of Agronomy, 1979.

20. Neill, L. L. "An Evaluation of Soil Productivity
Based on Root Growth and Water Depletion."
M.S. thesis, University of Missouri, Columbia,
Mo., 1979.

21. Ogg, C. W., R. E. Heimlich, and J. E. Hostetler.
"A Modeling Approach to Watershed Conserva-
tion Planning." Journal of Soil and Water Con-
servation, Vol. 35, No. 6, November-December
1980, pp. 271-273.

22. Ogg, C. W., J. D. Johnson, and K. C. Clayton. "A
Policy Option for Targeting Soil Conservation
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servation, Vol. 37, No. 2, March-April 1982,
pp. 68-72.

23. Pierce, F. J., W. E. Larson, R. H. Dowdy, and
W. A. P. Graham. "Productivity of Soils: Assess-
ing Long-Term Changes Due to Erosion." Jour-
nal of Soil and Water Conservation, Vol. 38,
No. 1, January-February 1983, pp. 39-44.

24. Robinette, C. E., J. E. Foss, and F. P. Miller.
"Soil Landscape and Corn Yield Relationship,"
M.S. thesis, University of Maryland, College
Park, 1982.


25. Shrader, W. D., and G. W. Langdale. "Effects of
Soil Erosion on Productivity." In Frontiers in
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26. Snedecor, G. W. Statistical Methods, 5th edition.
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27. Soil Conservation Society of America. Resource
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30. U.S. Department of Commerce, Bureau of the
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32. Williams, J. R., K. G. Renard, and P. G. Dyke.
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December 1978.







Bills & Heimlich


Appendix: Measures of Statistical Significance

Since the data presented in the text are based on a
sampling procedure, measures were taken to ex-
amine the statistical significance of differences in
landowner characteristics observed among erosion
classes. Appendix table 1 presents two kinds of chi
square tests for goodness of fit. First, we tested the
hypothesis that the distribution of owner-operator
characteristics among erosion classes is the same as
for the whole sample. The null hypothesis is that
owner-operators of land in the specific erosion class
have the same characteristics as all owner-operators.
Second, we tested the differences between the two
groups of owners of moderately erosive cropland.
The null hypothesis (HO in appendix table 1) in this
case is that owner-operators managing their land
both above and below tolerance level are drawn from
the same population.

The general formula used to calculate the chi square
statistic is:


S (- F)2
i-1 F


where: f = the observed frequency in an erosion
class;
F = either the frequency in the whole
population of owner-operators (test 1)
or in the population of owner-operators
of moderately erosive land (test 2);
n = the number of classes of the character-
istic (e.g., age groups).

This application of the chi square statistic to test
goodness of fit to a known distribution is described
in section 1.14 and 9.3 of Snedecor (26).

Appendix table 1 indicates that none of the differ-
ences between owner-operators of land in different
erosion classes are significant at commonly accepted
levels. There are no significant differences between
owner-operators of land in different erosion classes.


Appendix table 1-Statistical significance of the results

HO: Same population, all erosion classes
Managed Managed Highly HO: Same population,
Table and characteristic Nonerosive below T above T erosive moderately erosive

Chi square
(degrees of freedom)
Table 7: Age 2.14 0.32 2.56 0.32 1.12
(3) (3) (3) (3) (3)
Table 8: Size of holding 1.97 1.11 0.68 2.26 0.30
(2) (2) (2) (2) (2)
Table 9: Net farm income 0.33 0.12 1.01 1.73 1.50
(4) (4) (4) (4) (4)
Table 10: Education level 1.46 0.69 1.58 4.36* 3.96
(3) (3) (3) (3) (3)
Table 11: Principal occupation 2.58 0.79 2.83 1.38 3.04
(4) (4) (4) (4) (4)
Table 12: Type of ownership 0.16 0.22 1.58 0.75 2.09
(4) (4) (4) (4) (4)
*Significant at 75-percent level.


*U.S. GOVERNMENT PRINTING OFFICE : 1984 0-420-938/ERS-2158







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