Agricultural characteristics and fertilizer practices in the Cache La Poudre-South Platte irrigation area of northeastern Colorado

Material Information

Agricultural characteristics and fertilizer practices in the Cache La Poudre-South Platte irrigation area of northeastern Colorado
Series Title:
Technical bulletin Colorado Agricultural Experiment Station
Davan, Clarence Floyd
Anderson, Raymond Lloyd, 1927-
Hartman, Loyal M.
Place of Publication:
[Fort Collins]
Colorado Agricultural Experiment Station, Colorado State University
Publication Date:
Physical Description:
24 p. : ill. ; 23 cm.


Subjects / Keywords:
Irrigation -- Colorado ( lcsh )
Fertilizers -- Colorado ( lcsh )
bibliography ( marcgt )
non-fiction ( marcgt )


Includes bibliographical references.
General Note:
Cover title.
Technical bulletin (Colorado Agricultural Experiment Station)
Statement of Responsibility:
[C.F. Davan, Jr., R.L. Anderson, and L.M. Hartman].

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Full Text
Agricultural Characteristics and Fertilizer Practices
in the
Cache La Poudre-South Platte Irrigation Area of
Northeastern Colorado
\\ \ Technical Bulletin 78
Fo r t Q Greeley
Collins \e
mi les
Colorado Agricultural Experiment Station Colorado State University cooperating with the Farm Production Economics Division and the Resource Development Economics Division Economic Research Service, USDA.

This bulletin is being published tive of the 4-county area comprimarily to report descriptive prising the Northern Colorado data which were collected from Conservancy District Area. Howa survey of farms in the North- ever, holders of Colorado-Big ern Colorado Conservancy Dis- Thompson water represent aptrict Area. The original purpose proximately 70 percent of the of the survey was to estimate the irrigated farms so the data are on-farm adjustments which have applicable to a large number of taken place in response to sup- farms. plemental water from the Colo- The survey w a s conducted rado-Big Thompson project. Sur- under a cooperative project bevey data were collected on cur- tween the Department of Ecorent and past water and fertiliz- nomics, Colorado State Univerer application rates and it was sity and the Economic Research thought to be worthwhile to pre- Service, USDA. Dr. George Pasent these data in a separate re- v e li s, Resource Development port, since they are of some in- Economic Division, Economic Reterest in themselves to agricul- search Service, was very helpful turists who are concerned with in designing the survey questioncultural practices on irrigated naire. Acknowledgment is due farms. Frank Goode, research assistant,
The population of the sample who conducted the field interof farms surveyed is restricted views during the summer of to all farms having an allotment 1962, and to Charles W. Nauof Colorado-Big Thompson water. heim, Economic Research ServTherefore, the data reported in ice, who made many helpful sugthe bulletin are not representa- gestions on the report.

Summary----------------------------------------------------------------------------------------------------------------------------------------------------------------------- S
Description of Location and Soils in the Area-------------------------5
General Agricultural Characteristics of the Area 1949-59---------------B
Population and Number and Size of Farms-------------------6
Distribution of Farms by Size and Type-------------------- '7
Land Use in Area.---------------------------------------8
Fertilizer Use' in Area----..---------------------------------------------------------------------------------------------------------..~. 8
Crop Yields-------------.............................................................................................................. 9
lie source Ill se on F' ari~i s Stilrve3red----------------------------------1~ I.
~ Size and Land Use ..... ..--------------------------------------------------------------------------------------------------------------------U
~NTater 11s e on s---------------------------------------------------------------------------------------------------------------12
Fertilizer Use on Crops .~.---------------------------------------------------------------------------------------------------------------------------13
Fertilizer Analyses, Rates Applied, and Costs-----------------14
Appendix-------------------------------------------------------... -. --------------------------------------------------------------- ............................... -. 1'7

Agricultural Characteristics and Fertilizer Practices
In the Cache La Poudre-South Platte Irrigation
Area of Northeastern Colorado
C. F. Davan, Jr., R. L. Anderson, and L. M. Hartman1
This report considers current 1959 in the area, while the avand past characteristics of ir- erage size of irrigated farm inrigated farming in the Cache la creased from 296 to 419 acres. Poudre-South Platte irrigation Farm population decreased about area. Considered are: (1) land one-third in the area during the use and farm size, (2) irrigation same period. Yields of all pnnwater use by crops, (3) fertiliz- cipal irrigated crops, except dry er use including the constituent beans, in the area show higher analysis, rate applied, and costs, yields in 1956-60 than in 1950and (4) crop yields. The report 54. draws upon data from the U. S. Data from the farms surveyed
Census of Agriculture and from indicate that water application a survey of 150 irrigated farms rates per irrigated acre in the in the area conducted during the Cache la Poudre-South Platte irsummer of 1962. rigation area more than doubled
Irrigated crop acres per farm from 1951-53 to 1959-61. This is increased 18 percent from 1951- due to a series of above-average 53 to 1959-61 mainly because water years and the addition of the number of irrigated farms Colorado-Big Thompson R i v e r decreased and the size of the water. All major irrigated crops remaining farms increased. There received more water per acre in was a shift from low water-using the 1959-61 period as compared crops such as small grains to with the 1951-53 period. An avhigh water-using crops such as erage of 2.0 acre-feet was applied corn and sugar beets. The num- to irrigated crops in 1959-61 as ber of irrigated farms decreased compared with 0.9 acre-foot per by 1,179 farms from 1949 to acre in 1951-53.
1C. F. Davan, Jr., and R. L. Anderson, agricultural economists,: Farm Production Economics Division and Resource Development Economics Division, respectively, Economic Research Service, USDA, and L. M. Hartman, associate professor and economist, department of economics and sociology, Colorado State University, Fort Collins, Colo.

Eighty-nine percent of the ir- three-fourths of the fertilizer aprigation farmers surveyed in the plied to irrigated crops in the Cache la Poudre-South Platte ir- area during both periods was aprigation area 'fertilized t h e i r plied to sugar beets and corn. crops during..1959-61. This com- Fertilizers with high proporpares with 41 percent for 1951- tions of phosphate were used 53. during 1951-53. Fifty-eight perFertilizer use is closely related cent of the irrigated farms used with the per-acre value of the fertilizers containing 43 to 53 crop. High cash-return crops are percent available P205. During fertilized more heavily while low the 1959-61 period, irrigation cash-return crops are fertilized farmers used fertilizer mixtures less heavily; for example sugar containing higher percentages of beets received most of the ferti- nitrogen. The number of farmers lizer for both periods and pasture using fertilizer containing only received the least. More than phosphate decreased 55 percent.
Agriculture is a fast-changing In terms of acres of irrigated industry. Shifts are continually crops, 56 percent of the sugar occurring 'in numbers and sizes beets and dry beans, 42 percent of farms and in the production of the barley, 24 percent of the practices on Thtms. This report alfalfa, and 25 percent of the attempts to point out some of potatoes grown in the State are these changes during the 1950's produced in this area. In addition, in one of the largest irrigated the area has a large number of areas of Colorado. cattle-feeding operations. Over
The irrigated area in Boulder, one-third of the value of liveLarimer, and Weld Counties in stock including fed animals sold northeastern Colorado is an im- in the State came from this area. portant agricultural area of Col- This report shows past and orado. It contains about 8 per- current agricultural charactercent of Colorado's land in farms, istics of this three-county area about 20 percent of its irrigated in terms of soils; the number, land, and 25 percent of its ir- size, and kinds of farms; the rigated c r o p 1 a n d harvested, land, water, and fertilizer use; Nearly one-fourth of the Colo- and the crop yields. These data .rado irrigated farms are in this can serve as a benchmark for area. comparing future use of agricul-4-.

tural resources, especially water including water application rates, and fertilizer in northeastern crops grown, and fertilizer use Colorado. are taken from a survey of 150
T h e information presented irrigation farmers in the North should be useful to agronomists, ern Colorado Water Conservancy irrigation officials, fertilizer deal- District.2 Over 70. percent- of the ers, county agents, and others farms in the Conservancy Disconcerned with technical prob- trict hold allotments of Coloradolems of resource use in northern Big Thompson water. Names of Colorado. farmers to be interviewed were
The major characteristics are obtained from a stratified rantaken from census data and other dom sample of these allotment sources. Current use of resources, holders.
The irrigated uplands and val- Cache la Poudre and South Platte leys of northeastern Colorado River systems with adjacent flat are interspersed hardlands and bottoms and terraces. moderately sandy soils. The ma- The soils are brown, deep to
jor portion of the area comprises moderately deep, and range from parts of Boulder, Larimer, and sandy to moderately heavy in Weld Counties and contains ap- texture. The deep soils are deproximately 563,000 irrigated veloped principally from less or acres. The location of this area mixed less and outwash mateis shown on the cover and is rials. The moderately deep soils
designated in this study as the are mostly residual and developed Cache la Poudre-South Platte ir- from sandstone, s h a l e s, and rigation area. sandy shales. Small areas of
Elevation of the area ranges poorly drained and saline soils: from 4,500 to 5,280 feet above are interspersed throughout on sea level. Precipitation ranges both the uplands and bottomfrom 13 to 15 inches annually, lands. The physiography of the area Wind and water erosion are
is nearly level to gently undulat- moderately active on the cultiing with 1 to 3 percent slopes. vated lands. Gully erosion in unThe undulating to gently rolling protected irrigation ditches is a uplands are dissected by the major problem on the uplands.3
2 The survey was conducted during the summer of 1962.
* Payne, E. M. and Romine, D. S. Land Resource Areas of Colorado. Colo. Agr. Exp. Sta. GS Bul. 727, 55 pp., 1960.

Farming under irrigation is dryland farming. The principal the principal land use on the val- crops produced under irrigation ley terraces, bottomlands, and in the area are alfalfa, corn, sugfor much of the uplands. Land ar beets, dry beans, and small use on the uplands is an inter- grains. spersed pattern of irrigation and
Population, Number, and the area decreased by 1,575 from
Size of Farms 1949 to 1959 when the average
During the last decade, total size increased to 500 acres, an population o f t h e Cache la increase of 125 acres. There were Poudre-South Platte irrigation 1,179 fewer irrigated farms in area increased 25 percent or by 1959 as compared to 1949, a de41,000 persons, while farm pop- crease of 20 percent. The average ulation decreased over 32 percent size of irrigated farms increased or by 11,000 persons (table 1). from 296 acres in 1949 to 419 Farm population comprised 21.4 acres in 1959, an average inpercent of the total population crease of 123 acres. The 419
for the area in 1949. This fell to acres is comprised of 122 acres 11.5 percent in 1959. of irrigated land and 297 acres
The number of all farms in of dryland.
Table 1.-Population, number, and size of farms in the Cache la Poudre-South
Platte irrigation area, Colorado, 1949 and 19591
Total for area 2
Item Unit
1949 1959
Total No. 159,000 200,000
Farm No. 34,000 23,000
Farm as percent of total Pct. 21.4 11.5
All farms No. 7,479 5,904
Size of all farms (average) Acres 375 500
Irrigated farms No. 5,800 4,621
Size of irrigated farms (average) Acres 296 419
Irrigated acres/irrigated farm Acres 95 122
1 Source: U. S. Census reports.
2 The Cache la Poudre-South Platte area is comprised of Boulder, Larimer, and Weld Counties. Refer to appendix table 1 for comparison on an intercounty basis for 1949 and 1959.

Distribution of Farms by Platte irrigation area. Seventy
Size and Type percent of these farms are in
Weld County.
In the Cache la Poudre-South Most of the farms in the Cache
Platte irrigation area the number la Poudre-South Platte irrigation of irrigated farms containing area are classified by the census fewer than 100 acres decreased, as commercial farms. In 1959 and the number with 100 acres there were 1,223 fewer commeror more increased from 1954 to cial farms in the area than in 1959 (figure 1). In 1959 there 1949 (table 2). The change in were 1,000 fewer irrigated farms number by type of farm was as with less than 100 acres of land follows: General f a r m s, 784 than in 1954 and about 700 more fewer; field crop farms, 376 of the larger farms. More than fewer; poultry farms, 181 fewer; one-third of the 100- to 199-acre fruit and nut farms, 64 fewer; irrigated farms in the State are livestock farms, 115 more; and in the Cache la Poudre-South dairy farms, 67 more. Two-thirds
Figure 1.-Distribution of irrigated farms by size of farm in the Cache la
Poudre-South Platte irrigation area, Colorado, 1954 and 1959.1
of Percentage of f2rms
0 5 10 15 20 25 30 35 40
1 -49 --50-99
500-999 1954
1 Source: U. S. Census reports. Area is comprised of Boulder, Larimer, and Weld Counties. Refer to appendix table 2 for trends on an intercounty basis. Comparative data for 1949 is not available.
2Total number of irrigated farms for the area: 1949 5,800; 1954 4,742; and 1959 4,449.

Table 2.-Distribution of farms by type of farm in the Cache la Poudre-South
Platte irrigation area, Colorado, 1949 and 1959 1 Total for area *
Type of farm 2
1949 1959
Number Percent Number Percent
Livestock 1,736 28 1,851 37
Field crop 1,898 31 1,522 30
Dairy 776 13 843 17
General 1,434 23 650 13
Poultry 288 4 107 2
Fruit and nut 74 1 10 1
Total 6,206 100 4,983 100
1 Source: U. S. Census reports.
2 Miscellaneous, other, and unclassified farms omitted.
s Area is comprised of Boulder, Larimer, and Weld Counties. Refer to appendix table .3 for comparison of trends on each county in 1949 and 1959.
of the farms were classified as 1949 to 120,000 acres in 1959. 'livestock and field crop farms by Sugar beets made a significant the census in 1959. G general increase from 63,000 to 80,000
farms made the largest drop in acres. In 1959, alfalfa, corn, and numbers. In 1959, the area con- sugar beets accounted for about
tained 39 percent of the total two-thirds of the irrigated cropdairy farms in the State. land use in the area. Irrigated
Land Use in Area barley decreased from 106,000
One-fourth of the irrigated acres in 1949 to 63,000 acres in cropland harvested in the State 1959. Irrigated acreage of winter was in the Cache la Poudre-South wheat, dry beans, and potatoes Platte irrigation area in 1959. decreased very little from 1949 Now, the area generally harvests to 1959. more irrigated cropland acreage Fertilizer Use in Area in relation to the total irrigation In the Cache la Poudre-South acreage than the other irrigated Platte irrigation area, the use areas of the State. of commercially produced plant
The acreage of land irrigated nutrients increased 42 percent in the Cache la Poudre-South from 1954 to 1959. The plant Platte i r r i g a t i o n area has nutrient content of most fertilizchanged little since the introduc- er has increased considerably, altion of Colorado River water in though the tonnages of materials the mid-fifties (table 3). used have not increased consistThere has been a trend to- ently. Ninety-seven percent of all ward more acreage of high wa- primary nutrients used in Coloter-using crops in the area. The rado was applied to irrigated acreage of irrigated c or n in- land in 1959, compared with 95 creased greatly: 56,000 acres in percent in 1954.4 In 1959, ap.4 Davan, C. F., Jr., Schmehl, W. R., and Stewart, W. G., Fertilizer Use and Trends for Principal Cr6ps iii Colorado. Colo. Agr. Exp. Sta., cooperating with Economic Research Service USDA, GS Bul. 771, p. 21, 1962.

Table 3.-Land use in the Cache la Poudre-South Platte irrigation area,
Colorado 1949 and 1959 1
Total for area 2
1949 1959
1,000 acres
Land use
Land in farms 3,195 3,216
Cropland (harvested) 913 836
Land irrigated (census year) 554 563
Irrigated cropland (harvested) 515 523
Percent, land irrigated a 17.3 17.5
Selected irrigated crops 4
Alfalfa 125 130
Corn 56 120
Sugar beets 63 80
Barley 106 63
Beans (dry) 52 43
Oats 14 16
Potatoes 14 13
Wheat (winter) 13 11
1 Source: U. S. Census reports.
2 Area is comprised of Boulder, Larimer, and Weld Counties. fRefer to appendix table 4 for comparison of trends on an intercounty basis for 1949 and 1959.
* Total irrigated land as a percentage of all land in farms.
S Harvested acres. Spring wheat, rye, sorghum, other hay crops, and other vegetable crops omitted. Not all irrigated crops are included.
proximately 29 percent of the dry and 36 percent of the liquid Crop Yields fertilizer applied in the State All principal irrigated crops,
was applied in this area. In 1959, except dry beans, in the Cache acres fertilized in the area in- la Poudre-South Platte irrigation creased 50 percent over 1954 area show higher yields in 1956(table 4). Total fertilizer used on 60 than in 1950-54 (table 5). each major crop in the area in- This increased production is uncreased except for potatoes and doubtedly a function of many other pasture. variables, some of which are
Corn and sugar beet acreage climate, moisture, increased rate received approximately 72 per- of irrigation water per acre, cent of the total fertilizer used fertilizer rates, and other technoin the area during 1959. Corn logical advances during the late received the biggest increase in 1950's. However, year to year, fertilizer: 3,762 tons more were or period to period, changes in used in 1959 than 1954. Appli- yields contain a random element cation of fertilizer on sugar beets due to climate and other exogeincreased by 2,762 tons in 1959 nous and endogenous factors.
over application in 1954. About Therefore, it would be hazardous one-half of the fertilizer applied to interpret changes between the to sugar beets in the State dur- two periods of the report withing the 1959 crop year was ap- out some measure of this random plied in the Cache la Poudre- element. Census data for 1959 South Platte irrigation area. on irrigated crop yields for the

Table 4.-Fertilizer used in the Cache la Poudre-South Platte irrigation area,
Colorado, 1954 and 1959 1
Total for area*
Item. Unit
1954 1959
Dry tons 15,469 17,923
Liquid 2 tons .......... 4,108
Acres fertilized: 1,000 138 207
Amount used on: *
Sugar beets tons 6,117 8,879
Corn tons 3,190 6,952
Hay and cropland pasture tons 1,369 1,662
Potatoes' tons 1,893 1,502
Other crops tons 2,503 2,895
Other pasture tons 218 141
1 Source: U. S. Census. Data not available for 1949.
2 Not reported as liquid for 1954.
a Minor crops not included.
'1954 census included vegetables and fruits.
s Area is comprised of Boulder, Larimer, and Weld Counties. Refer to appendix table 5 .for comparison of fertilizer use trends in each county in 1954 :and 1959. .
Table 5.---Yields of irrigated crops in the Cache la Poudre-South Platte
irrigation area, Colorado, 1950-54 and 1956-60 1
5-year average per
harvested acre
. Crop Unit
1950-54 1950-60 Change
Sugar beets a tons 16.6 17.6 + 1.0
Corn bu. 54.9 71.4 + 16.5
Beans (dry) lbs. 1,767.0 1,707.0 60.0
Barley bu. 37.3 45.3 + 8.0
Wheat (whiter) bu. 25.3 34.0 + 8.7
Potatoes cwt. 210.0 215.0 + 5.0
Alfalfa hay a tons 2.7 2.8 + .1
1Data acquired from the Colorado Agricultural Statistics Office, Colorado Department of Agriculture cooperating with the U. S. Department of Agriculture-SRS, 330 Custom House, Denver 2, Colo. Based on irrigated crop yields of Boulder, Larimer, and Weld Counties. Refer to appendix table 6 for yields for each county.
2 Weighted average according to acreages harvested per farm.
8 Not estimated separately for irrigated and nonirrigated. Approximately 90 percent of the alfalfa acreage and 99 percent of the sugar beet acreage (1950-54) in the State was irrigated. 1956-60 sugar beet yields are only for irrigated acreages harvested.

area of this survey indicate that increased m a i n 1 y because of the magnitude of the random three principal causes (1) low
element has been between 10 and level of available soil phosphorus, 15 percent. Thus, one could safe- (2) poor irrigation practices, and ly conclude that any change (3) the failure to use adapted g r e a t e r than this is due to varieties. Because of low ecochanges in water, fertilizer, crop nomic returns from alfalfa as a variety, and other technological cash crop, seedings are often advances. Clearly, corn, barley, made on a field of lower fertility and wheat have increased yields and also on fields more difficult greater than would be expected to irrigate. In addition, during from random variation. Sugar the rush season for irrigation, beets, potatoes, and alfalfa hay alfalfa is often neglected for show some increase but not great other crops of higher cash value. enough to conclude that it is due With good management practices to improved practices or vare- alfalfa yield per acre in the State ties. could probably be increased as
Alfalfa hay yields have not much as 50 percent.5
Farm Size and Land Use on the farms raising these crops
The farms surveyed averaged followed by barley, beans, wheat, 182 acres of cropland per farm and potatoes. In terms of land (160 irrigated acres and 22 dry- area devoted to these crops, alland acres) in 1959-61 (table 6). falfa and corn each occupy slightRow crops and alfalfa are the ly more than one-fourth of the most important crops grown on irrigated area. Sugar beets and these farms. About 82 percent barley occupy about 16 'percent of the farms grew corn, 67 per- each. Other crops are of minor cent grew sugar beets, and about importance in land area occupied half raised dry beans. Alfalfa but are important on the farms was grown on 95 percent of the growing them. Alfalfa, corn, and farms. sugar beets utilize over twoAcreages of major irrigated thirds of the total irrigated crops on survey farms m the
u i cropland on the survey farms. Cache la Poudre-South Platte Irrigation area are also shown in This is very close to the acreages table 6. Alfalfa, corn, and sugar reported in the 1959 Census of beets occupy the largest acreages Agriculture for this area.
5 Schmehl, W. R., and Romsdal, S. D. Materials and Methods of. Application of Phosphate for Alfalfa in Colorado. Colo. Agr. Exp. Sta. Tech. Bul. No. 74, 1963.

Table 6.-Land use and crop acreages on the average farm surveyed, Cache
la Poudre-South Platte irrigation area, Colorado, 1959-611
Average farm Average Percentage
Percentage acreage of survey
Item crop is of on farms farms
Size irrigated reporting reporting
land the crop the crop
Acres Percent Acres Percent
Land in farm
Cropland irrigated ................ 12640
Alfalfa .................................. 27.2 44 95
Corn .........................---- ........- 25.5 48
Sugar beets .......................... 16.6 38 67
Barley .................................. 16.1 29 85
Beans, dry ............................ 10.5 30 53
Wheat ....-..-...-..-...-. .. ....--.. 2.5 35 1I1
Potatoes ...-......-..-.-.........-. .0.9 35 3
Pasture .0.............................. O.9 47 3
Cropland dry .......................... 22
1 Data from 1962 survey of 150 irrigation farmers in the Cache la Poudre-South Platte irrigation area.
Water Use on Crops The average water application
Farmers interviewed w e r e rate per acre applied to crops on asked how much water they ac- the survey farms more than
tually used on various crops. Wa- doubled from 1951-53 to the ter application varies on crops 1959-61 period going from 0.9 due to the requirements of the acre-foot per acre in 1951-53 to crop, soil type, amount of water an average of 2.0 acre-feet per available, and management prac- acre in 1959-61. The 2 acre-feet tices of the operator. per acre compares to 2.16 acreWater application rates per feet per acre of available water irrigated acre increased signifi- on 375 farms sold in this area cantly on the farms surveyed between 1954 and 1959.6 The from the 1951-53 period to the average increase from 1951-53 to 1959-61 period as shown in table 1959-61 for all crops was 1.1 7. Farmers in the area generally acre-feet per acre. All major irhad a better supply of irrigation rigated crops of the farms surwater during the 1959-61 period veyed received more water per because of more favorable water acre in the 1959-61 period than years and the addition of Colo- in the 1951-53 period. Pasture rado-Big Thompson water to the and wheat on the survey farms area. New irrigation wells also received no significant amount contributed to the increased wa- of irrigation water during the ter supply. With more water 1951-53 period; however, during available it would be expected the 1959-61 period, pasture and that farmers would apply more wheat received 2.5 acre-feet and water per acre. 1.0 acre-foot, respectively.
* Hartman, L. M. and Anderson, R. L., Estimating the Value of Irrigation Water. Colo. Agr. Exp. Sta., cooperating with Economic Research Service-USDA, Tech. Bu1. 81.

Table 7.-Water used on irrigated crops, 150 survey farms, in the Cache la
Poudre-South Platte irrigation area, Colorado, 1951-53 and 1959611
Water rates per irrigated acre 2
Crop Increase over
1951-53 15%9-61 1951-53
.....................nacre feet ....................
Sugar beets 1.7+ .34 2.2.1 0.5
Corn 1.6 .3 1.8 .1 0.2
Beans 0.6 .1 1.7+.1 1.1
Barley 0.5+ .2 1.5+.1 1.0
Wheat 1.0.1 1.0
Potatoes 1.0+ .3 2.7.3 1.7
Alfalfa 0.7+ .2 2.6+.2 1.9
Pasture 2.5+.8 2.5
Average 3 0.9+ .2 2.0+.1 1.1
1 Farms were surveyed in 1962.
Weighted average according to acreage irrigated per farm.
S Weighted average according to acreage irrigated per crop.
' + .3 is the range in acre-feet of water applied.
Fertilizer Use on Crops mercial fertilizer and irrigation
Eighty-nine percent of the water since experimental results farmers surveyed in the Cache and experience indicate fertilizer la Poudre-South Platte irrigation and water are complementary area applied commercial fertilizer inputs. Farmers are aware of the on their crops during 1959-61. increase in crop yields from inThis compares with only 41 per- creased f e r t il .z e r application
cent in 1951-53. Fertilizer use when adequate quantities of waon irrigated crops on the survey ter are applied. This is no doubt farms in 1959-61 increased about of major consequence in explain6 times over the fertilizer used ing the heavier applications of during the 1951-53 period. Sur- fertilizer reported in the survey. vey farmers that fertilized, used Fertilizer used per irrigated
annually 4.1 tons per farm dur- crop is closely correlated with the ig the 1959-61 period. This com- per-acre value of the crop. Highpares to an average of 4.3 tons est percentages of fertilizer used per farm using fertilizer esti- are associated with high cashmated by Davan, et al., in 1960.' return crops, and the lowest perOne would expect a positive centages with the 1 0 w cashcorrelation between use of com- return crops. For example, sugar
7 Op. cit., page 6, figure 4.

beets received most of the ferti- Cache la Poudre-South Platte irlizer for both periods and pasture rigation area and since these received the least (table 8). crops are heavy users of phosSixty-five percent of all ferti- phate, the primary fertilizer used lizer applied to irrigated crops by irrigation farmers contained during 1951-53 on farms sur- high portions of available P205. veyed was applied to sugar beets. Fifty-eight percent of the irriAll kinds of irrigated crops re- gated farms surveyed used ferticeived s o m e fertilizer during lizer containing 43 to 53 percent 1959-61, whereas in the 1951-53 available P205 during the early period wheat and pasture were 1950's (table 9). Thirty-eight
not fertilized. More than three- percent of the fertilizer used in fourths of the fertilizer applied 1951-53 contained only P205. to irrigated crops during both In the 1959-61 period the irriperiods w a s applied to sugar gation farmers used more fertibeets and corn. Total fertilizer lizer mixtures containing higher applied to sugar beets per year percentages of nitrogen. Use of during 1959-61 was about 6 times fertilizer mixtures containing 20 greater than for the 1951-53 percent or more nitrogen inperiod. Corn increased in both creased 51 percent from 1951-53 total pounds and percentages. to 1959-61. During the same period the use of fertilizer containFertilizer Analyses, Rates ing only available P205 decreased
Applied, and Costs 55 percent. Over one-fourth of
Legumes and root crops re- the farmers interviewed used
ceived most of the fertilizer dur- ammonium nitrate, containing ing the 1951-53 period in the 33 percent nitrogen, during 1959Table 8.-Distribution of fertilizer use on irrigated crops, 150 survey farms,
in the Cache la Poudre-South Platte irrigation area, Colorado,
1951-53 and 1959-611
Fertilizer used 2
Irrigated crop
1951-53 1959-61
Sugar beets 65.2 43.9
Corn 17.3 33.7
Beans 0.2 3.5
Barley 9.4 5.2
W heat --.-.-.. 1.5
Potatoes 1.7 1.1
Alfalfa 6.2 9.6
Pasture ........ 1.5
Total 100.0 100.0
1 Farms were surveyed in 1962.
2 Percentage of the total fertilizer applied to each crop on farms

61. Anhydrous ammonia, 82 per- ported by survey farmers for ircent nitrogen, was used in the rigated crops in this area. No aparea during this period. However plication of K20 indicates the the survey did not reflect its use. high potassium-supplying power Much of the nitrogen fertilizer of the soils in the area. was applied to small grains and This increase in the use of pastures. primary plant nutrients has been
Fertilizers containing both ni- due partly to the extension protrogen and available P205 were gram and farmer education on applied to sugar beets, corn, bar- fertility in the Cache la Poudreley, and potatoes in the area dur- South Platte irrigation a r e a. ing 1951-53 (table 10). Wheat Many fertilizer dealers hold ferand pasture, on the farms sur- tility education programs for the veyed, received no fertilizer dur- farmers. Government programs ing this period. During the 1959- have an indirect influence on in61 period, the average analysis creasing the use of plant nutriof fertilizer applied to irrigated ents. Reduced acreage of some crops increased in both nitrogen crops, because 'of government and available P205 as compared programs, have induced many
with 1951-53. farmers to concentrate on obQuantities of nitrogen, as giv- taining higher yields on less acreen in table 10, applied per irri- age; one way to accomplish this gated acre have increased for all is with increased application of principal crops except beans and fertilizer. barley from 1951-53 to 1959-61. When the use of one resource,
Phosphate applications also in- such as water, is increased, the creased for all irrigated crops. marginal productivity of other Application of zero K20 was re- resources, such as fertilizer, is
Table 9.-Analyses of fertilizers used on irrigated crops, 150 survey farms,
in the Cache la Poudre-South Platte irrigation area, Colorado, 195153 and 1959-611
Fertilizer Farms using each analysis
1951 1959-61
N-PgOs-K20 Percent
0-43-0 7.0 2.4
0-45-0 23.0 17.6
0-46-0 8.0 4.5
16-48-0 2.1
21-53-0 4.6 11.9
33- 0-0 19.5 26.0
33-45-5 6.9 14.0
33-46-0 8.0 6.6
Misc. mixtures 2 23.0 14.9
Total 100.0 100.0
1 Farms were surveyed in 1962.
tMiscellaneous mixtures consisted of (1) 25-41-0; (2) 25-50-0; (3) 16-22-0; (4) 25-38-0; and (5) 18-36-0.

increased. Increasing the use of The per-pound price of nitrowater probably increases the gen, phosphate, and potash in
marginal productivity of ferti- the area dropped from 1949 to lizer more than other resources. 1959, table 11. Nitrogen made This might not be the case the the biggest drop, 3.7 cents per first year of irrigation, but it pound, while phosphate and potbecomes increasingly important ash dropped 1.8 and 0.6 cents, as the years go on. respectively.
Table 10.-Rate of primary plant nutrients applied per acre of irrigated crop,
150 survey farms, in the Cache la Poudre-South Platte irrigation
area, Colorado, 1951-53 and 1959-611
Rate of application of nutrients per
Irrigated crops fertilized acre 2
1951-53 1959-61
N-P2Os-KzO N-PzOs-KO
Sugar beets 23-56-0 50-93-0
Corn 29-14-0 54-33-0
Beans 33- 0-0 28-31-0
Barley 29-32-0 27-73-0
Wheat (winter) .......... 31-52-0
Potatoes 61-30-0 77-130-0
Alfalfa 0-44-0 16-66-0
Pasture ............ 48-67-0
1 Farms were surveyed in 1962.
2 Rates of application of primary plant nutrients per acre are weighted according to the fertilized crop acreage per farm per crop.
Table 11.-Cost per pound of primary plant nutrients to farmers in the Cache
la Poudre-South Platte irrigation area, Colorado, 1949, 1954, and
Plant Year
nutrient 1949 1954 1959
........................OCents .......................
Nitrogen 15.2+.892 13.7+.60 11.5+.49
Available P20 10.2+.61 9.1+.40 8.4+.31
Potash 6.5+.25 6.0+.23 5.9-+.28
1 Estimated from survey of fertilizer dealers in the Cache la PoudreSouth Platte irrigation area.
2 +.89 is the range in cents per pound paid for primary plant nutrient, in this case nitrogen.

Appendix Table 1.-Population, number, and size of farms in Boulder, Larimer, and Weld Counties, Colorado, 1949 and 1959 1
1949 1959
Item Units
Boulder Larimer Weld Boulder Larimer Weld
Total 1,000 persons 48.3 43.7 67.5 74.3 53.3 72.3
Farm 1,000 persons 6.1 8.0 20.3 3.4 4.9 14.2
Farm as percent of total 2 Percent 12.6 18.3 30.1 4.6 9.2 19.6
All farms No. 1,320 1,741 4,418 882 1,292 3,730
Average size Acres 201 430 494 326 596 579
Irrigated farms No. 1,047 1,392 3,361 698 1,087 2,836
Average size Acres 187 440 262 361 538 356
Irrigated acres per farm Acres 70 82 109 106 102 134
i Source: U. S. Census reports.
- Percentage of total population for the county.

Appendix Table 2.-Distribution of irrigated farms by size of farm in Boulder, Larimer, and Weld Counties, Colorado, 1949, 1954, and 1959'
1949 1954 19~9
Boulder Larimer Weld Boulder Larimer Weld Boulder Larhuier Weld
ticres--------------------------------------------------------------------------F'ercent----------------------------------------------------ito 49 49 44 19 46 44 19 32 31 10
50to99 24 23 32 31 29 36 25 22 24
I- 100 to 199 21 25 40 20 21 36 28 32 45
* 200 to 4992 6 8 9 3 5 8.7 14 14 18.5
500 to 999 0 0 0 0 1 0.2 0.9 0.9 2.4
1,000+ 0 0 0 0 0 0.1 0.1 0.1 0.1
All farms 100 100 100 100 100 100 100 100 100
irrigated 1,047 1,392 3,361 614 1,116 3,012 638 1,008 2,803
farms (no.)
'Source: U. S. Census report.
2 Reported as 200 acres and over for 1949.

Appendix Table 3.-Distribution of farms by type in Boulder, Larimer, and Weld Counties, Colorado, 1949 and 19591
Type 1949 1959
farm 2 Boulder Larimer Weld Boulder Lartmer Weld
Livestock 239 486 1,011 268 477 1,106
Field crops 109 241 1,548 127 167 1,228
Dairy 255 173 348 162 190 491
General 156 238 1,040 43 107 500
Poultry 143 79 66 46 15 46
Fruit and nut 13 56 5 5 5........
Total 915 1,273 4,018 651 961 3,371
' Source: U. S. Census report.
SAll farm types not included.

Appendix Table 4.-Land use in Boulder, Larimer, and Weld Counties, Colorado, 1949 and 1959 1
1949 1959
Boulder Larimer Weld Boulder Lnrimer Weld
L a n d u se...0... .cres.............1 O 0 0c e.................................. ........... .
All land in farms 266 749 2,181 288 771 2,158
All cropland (harvested) 87 146 6S0 78 127 631
Land irrigated (census year) 73 113 367 74 110 379
Irrigated cropland (harvested) 63 100 353 59 99 365
Percent, land irrigated 27.4 15.1 16.8 25.7 14.3 17.6
' Selected irrigated crops 2
Sugar beets 2.9 8.6 51.8 2.8 8.7 68.2
Corn 10.3 10.3 35.2 14.7 22.3 83.2
Barley 14.9 23.2 68.0 11.1 13.7 38.3
Wheat (winter) 2.5 2.2 8.0 2.5 2.3 6.5
Oats 3.0 3.8 6.7 3.5 3.8 8.7
Alfalfa 16.5 27.5 81.0 14.7 29.5 86.0
Beans (dry) ........ 1.0 51.1 0.3 2.9 39.3
Potatoes ........ 0.3 13.5 ........ 0.1 12.5
'Source: U. S. Census reports.
2 Harysted acres. Spring wheat, rye sorghum, other hay crops, and other vegetable crops omitted.

Appendix Table 5.-Fertilizer used in Boulder, Larimer, and Weld Counties, Colorado, 1954 and 1959 1
. . Total for the area
Item Unit
1949 1959
Boulder Lartimer Weld Boulder Larimer Weld
Dry Tons (1,000) 1.1 2.9 11.6 2.0 3.1 12.9
Liquid 2 Tons (1,000) ............... 3 3.4
Acres fertilized Acres (1,000) 10.3 26.0 102.0 23.2 32.5 151.0
Amount used on: *
Sugar beets Tons 198 835 5.084 378 1,155 7,346
Corn Tons 339 810 2,041 945 1,120 4,887
Hay and cropland pasture Tons 159 536 674 351 540 771
Potatoes Tons 115 50 1,728 ........ 34 1,468
Other crops Tons 223 565 1,715 518 653 1,724
Other pasture Tons 20 52 146 80 21 40
1 Source: U. S. Census. Data for 1949 is not available.
2 Not reported as liquid for 1954.
3 Minor crops not included.

Appendix Table 6.-Yields of principal irrigated crops in Boulder, Larimer, and Weld Counties, Colorado, 1950-54 and 1956-60 1
Yield per harvested acre 2
Crop Unit 1950-54 1950-60
Boulder Larimer Weld Boulder Larimer Weld
Sugar beets 2 Ton 15.3 13.9 17.1 17.5 16.5 17.7
Corn Bu. 53.0 50.6 56.0 68.8 69.2 72.4
Beans (dry) Lb. 1,424.0 1,516.0 1,770.0 1,584.0 1,588.0 1,717.0
Barley Bu. 35.4 36.6 37.8 45.8 48.4 44.0
Wheat (winter) Bu. 24.4 26.2 25.4 35.0 34.8 33.2
Potatoes Cwt. 172.0 211.0 .--......... 200.0 215.0
Alfalfa hay 3 Ton 2.4 2.5 2.8 2.5 2.8 2.9
' Data acquired from the Colorado Agricultural Statistics Office, Colorado Department of Agriculture-SRS, 330 Custom
House, Denver 2, Colo.
2 Weighted average according to acreages harvested.
*Not estimated separately for irrigated and nonirrigated. Approximately 90 percent of the alfalfa and 99 percent
of the sugar beet acreage (1950-54) in the State was irrigated. Sugar beet yields for 1956-60 are only irrigated acreages harvested.

Appendix Table 7.-Principal nitrogen fertilizer materials and their nitrogen content 1
Nitrogen (N)
Material approximate content
Anhydrous ammonia 82
Urea 42
Ammonium nitrate 33.5
Ammonium sulfate-nitrate 26
Diammonium phosphate 21
Calcium cyanamid 21
Nitrogen solutions 37-45
Ammonium sulfate 20.5
Ammonium phosphate-sulfate 16
Potassium nitrate 13
Monoammonium phosphate 11
Organic products:
Activated sewage sludge 5-6
Animal tankage 5-10
Coffee grounds 2.1
Dried sheep manure 1.4
Cattle manure 1
I Major source of material: Lyon, T. L., Buckman, H. O., and Brady, N. C., The Nature and Properties of Soils. Sixth Edition. The Macmillan Company, New York, N. Y., pp. 478, illus., 1960.
Appendix Table 8.-Principal phosphate fertilizer materials and their phosphate content
Phosphate (P20s)
Material approximate content
Calcium metaphosphate 62-63
Phosphoric acid 54
Diammonium phosphate 53
Monoammonium phosphate 48
Superphosphates 16-50
Ammonium phosphate 20
Ammonium phosphate-sulfate 16-39
Organic products:
Activated sewage sludge 2-4
Animal tankage 3-13
Coffee grounds 0.4
Dried sheep manure 0.9
Cattle manure 1
I Major source of material: Lyon, T. L., Buckman, IH. O., and Brady, N. C. The Nature and Properties of Soils, Sixth Edition. The Macmillan Company, New York, N. Y., pp. 482, illus., 1960.

Appendix Table 9.-Principal potash fertilizer materials and their potash contents 1
Potash (KzO)
Material approximate content
Potassium chloride (muriate of potash) 48-60
Potassium sulfate 48-50
Sulfate of potash-magnesia 25-30
Manure salts 20-30
Potassium nitrate 44
Kainit 12-16
Organic Droducts:
Dried sheep manure 2
Cattle manure 1
Coffee grounds 0.4
Tobacco stems 4-9
'Major source of material: Lyon, T. L., Buckman, H. O., and Brady, N. C. The Nature and Properties of Soils. Sixth Edition. The Macmillan Company, New York, N. Y., pp. 486, illus., 1960.