• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Exercises
 Back Cover
 Copyright






Title: From agronomic data to farmer recommendations
ALL VOLUMES CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00080067/00002
 Material Information
Title: From agronomic data to farmer recommendations an economics workbook
Physical Description: iv, 59 p. : ill., forms ; 28 cm.
Language: English
Creator: CIMMYT Economics Program
CIMMYT Economics Program
Publisher: CIMMYT Economics Program
Place of Publication: Mexico D.F. México
Publication Date: 1988
 Subjects
Subject: Agriculture -- Economic aspects -- Study and teaching   ( lcsh )
Agriculture -- Research -- On-farm   ( lcsh )
Agriculture -- Economic aspects -- Research   ( lcsh )
Agricultural innovations -- Economic aspects   ( lcsh )
Genre: international intergovernmental publication   ( marcgt )
non-fiction   ( marcgt )
 Notes
General Note: Accompanied by booklet, 'Answers to workbook exercises' in pocket.
 Record Information
Bibliographic ID: UF00080067
Volume ID: VID00002
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 18538383
isbn - 9686127194

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Title Page 1
        Title Page 2
    Exercises
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
    Back Cover
        Back Cover
    Copyright
        Copyright
Full Text

































EC -O O IS- PROGSA




IAnwr to Wokbo Exercise


From Agronomic Data to
Farmer Recommendations


C


MMY T


ECNMC PROGRAM




































The International Maize and Wheat Improvement Center (CIMMYT) is
an internationally funded, nonprofit scientific research and training
organization. Headquartered in Mexico, the Center is engaged in a
worldwide research program for maize, wheat, and triticale, with
emphasis on food production in developing countries. It is one of 13
nonprofit international agricultural research and training centers
supported by the Consultative Group on International Agricultural
Research (CGIAR), which is sponsored by the Food and Agriculture
Organization (FAO) of the United Nations, the International Bank for
Reconstruction and Development (World Bank), and the United
Nations Development Programme (UNDP). Donors to the CGIAR
system are a combined group of 40 donor countries, international and
regional organizations, and private foundations.

CIMMYT receives core support through the CGIAR from a number of
sources, including the international aid agencies of Australia, Austria,
Brazil, Canada, China, Denmark, Federal Republic of Germany,
Finland, France, India, Ireland, Italy, Japan, Mexico, the Netherlands,
Norway, the Philippines, Spain, Switzerland, the United Kingdom, and
the USA, and from the European Economic Commission, Ford
Foundation, Inter-American Development Bank, OPEC Fund for
International Development, UNDP, and World Bank. CIMMYT also
receives non-CGIAR extra-core support from Belgium, the International
Development Research Centre, the Rockefeller Foundation, and many
of the core donors listed above.

Responsibility for this publication rests solely with CIMMYT.

Correct Citation: CIMMYT. 1988. From Agronomic Data to Farmer
Recommendations: Answers to Workbook Exercises. Mexico, D.F.:
CIMMYT.


ISBN 968-6127-28-3








a. Farmers
b. Researchers
c. Policymakers


1. C
2. B
3. D
4. A


a. Yes, this experiment can be analyzed.
b. No. The nonexperimental variables should be
representative of farmers' practice.
c. No. The farmers' practice (variety, seeding rate) should
be included as one of the treatments.


I Exercise 1


I Eercse


I Exercise 3








I Execise


Field B or Field D would be acceptable. Note that there is
no information about average size of fields in the research
area. Unless there is evidence that field size might affect
the type of fertilizer recommendation, then either B or D
could be used for the experiment.

Field A is prepared differently from the majority of fields
and researchers would want to think carefully before
putting an experiment there. Field C has a different
rotation which would obviously disqualify it for a fertilizer
experiment.


a. Adjusted yield

b. Total costs that vary

c. Net benefits

d. 740

e. 180

f. 780


Execs 6


The marginal rate of return is 80%.

470 -430 40
0 430 4 = 0.8 = 80%
200 150 50









a. 2 (variability due to environmental risks)

b. 3 (variability due to economic factors)

c. 1 (variability between locations)


I Exerise 8


a. Insecticide X
Insecticide Y
Labor to apply Insecticide X
Labor to apply Insecticide Y
b. Urea (+ transport)
Labor to apply fertilizer at planting
Labor to apply fertilizer at 30 days

c. Seed
Herbicide A
Labor to random plant 30,000 plants/ha
Labor to row plant 50,000 plants/ha
Labor for hand weeding
Labor for applying herbicide
Labor for carrying water to mix with herbicide
Rental of sprayer


I xec se


a. Field price of Insecticide A = $4/kg
b. Field cost of Insecticide A in Treatment 1 = $20/ha

c. Field cost of Insecticide A in Treatment 2 = $40/ha


I Exercise 7 1







Exrcs 10


a. Cost of 45 kg ammonium sulphate $740
Transport of 45 kg $ 95
Field price of 45 kg ammonium sulphate $835
$835
Field price of ammonium sulphate = 5 $18.6/kg
45


b. Cost of 45 kg triple superphosphate $1,620
Transport of 45 kg $ 95
Field price of 45 kg triple superphosphate $1,715
$1,715
Field price of triple superphosphate = $1715= $38.1/kg
45


c.$1860 = $88.60/kg, field price of N
0.21


d. $38.10 = $82.80/kg, field price of P205
0.46


Treatment 1

1 plowing $200/ha
2 harrowings $200/ha
Cost of tractor preparation $400/ha

Treatment 2

$35/day
$3 /day = $140/ha, cost of plowing with horse
1/4 ha/day


Exercise 11











5 days/acre
0.4 ha/acre

Wage rate
Meals
Total


12.5 days/ha

$35/day
$10/day
$45/day

$45/day
x 12.5 days
$562.5,cost of weeding 1 ha


Insecticide X ($/ha)
Insecticide Y (Sha)
Labor ($/ha)
Total costs that vary ($/ha)


0
0
0
0


30.0
0.0
7.5
37.5


Nitrogen ($/ha)a/
Labor ($ha)
Total costs that vary ($/ha)


2,000
80
2,080


2,000 2,000
80 160
2,080 2,160


Cost of urea $21.50/kg
Transport $ 1.50/kg
Field price of urea $23.00/kg
$23.00
Field price of N = 0. = $50/kg
0.46


Treatment

1 2 3


0.0
9.6
5.0
14.6


Treatment

1 2 3 4


3,000
160
3,160


LEx:ercise 12


Exrcse1











Treatment

1 2 3 4


Seed (S/ha)
Herbicide A (S/ha)
Labor for planting (S/ha)
Labor for hand weeding
(S/ha)
Labor for applying
herbicide (S/ha)
Labor for hauling water
(S/ha)
Sprayer rental (S/ha)
Total costs that vary (S/ha)


480
0
1,000


480
2,500
1,000


800
0
1,500


6,000 0 6,000


0 1,000


0
0
7,480


500
600
6,080


0 1,000


0
0
8,300


Recommendation Domain A


Average yield (kg/ha)


Treatment

1 2 3 4

726 568 1,208 1,044


Recommendation Domain B


Average yield (kg/ha)


Treatment

1 2 3 4

2,105 1,955 2,480 3,068


800
2,500
1,500


500
600
6,900


Exercise 13
0












Tillage costs ($/ha)
Labor for planting (S/ha)
Labor for weeding (S/ha)
Total costs that vary (S/ha)


Plow


11.20
6.00
24.00
41.20


Tine

4.75
2.40
42.00
49.15


The plow method has lower total costs that vary. If there
is no difference in yield between the two methods, then
the plow method is preferable.


IExrcise


Treatment


Average yield (kg/ha)

Adjusted yield (kg/ha)


Farmers receive $1.60/kg.

Transport
Harvest ($40/300 kg)
Shelling ($40/400 kg)
Costs proportional to yield


11,100 14,900 17,700

9,990 13,410 15,930


$0.10/kg
$0.13/kg
$0.10/kg
$0.33/kg


Field price = $1.60 $0.33 = $1.27/kg







I E s 1


Selling price $2.20/kg

Discount $0.11/kg
Transport $0.16/kg
Costs proportional to yield $0.27/kg


Field price of wheat = $2.20 $0.27 = $1.93/kg

Note that harvest costs are not proportional to yield (the
combine operators charge by the hectare), so these costs
are not included in the calculation of the field price.


I Exerci se1


Treatment
1 2 3 4
Average yield (kg/ha) 1,740 2,430 1,420 2,790
Adjusted yield (kg/ha) 1,392 1,944 1,136 2,232
Gross field benefits ($/ha) 14,755 20,606 12,042 23,659

Field price of maize = $12.00 ($0.60+$0.80) = $10.60














Average yield (kg/ha)
Adjusted yield (kg/ha)
Gross field benefits
(S/ha)a/
Insecticide cost ($/ha)
Application cost (S/ha)
Total costs that vary
($/ha)
Net benefits (S/ha)


Treatment
1 2 3 4

2,717 2,635 2,917 3,233
2,174 2,108 2,334 2,586

500 485 537 595
0 12 24 30
0 6 12 9


0
500


36
501


39
556


a/ Field price of maize = $0.23/kg


Exercise19B


Treatment

1 2 3


Average yield (kg/ha)
Adjusted yield (kg/ha)
Gross field benefits (S/ha)
Cost of weeding ($ha)
Cost of nitrogen (S/ha)al
Cost of application (S/ha)
Total costs that vary ($/ha)
Net benefits ($/ha)


2,000
1,800
27,000
1,200
0
0
1,200
25,800


a/ Field price of N 18.40 $40/kg
0.46


2,500
2,250
33,750
1,200
2,000
100
3,300
30,450


3,000
2,700
40,500
2,400
2,000
100
4,500
36,000


Exercise 19A^








I Exrcse2


Field price of wheat = $4.00 ($0.30 + $0.20) = $3.50/kg
$5.10 S0.60
Field price of straw -= -1 $060 = $0.25/kg
kgTreatment
Treatment


Grain yield (kg/ha)
Straw yield (kg/ha)

Adjusted grain yield
(kg/ha)
Adjusted straw yield
(kg/ha)

Gross field benefits, grain
($/ha)
Gross field benefits, straw
($/ha)

Total gross field benefits
(S/ha)

Cost of nitrogen ($/ha)
Cost of application ($/ha)

Total costs that vary (S/ha)
Net benefits (S/ha)


1

1,500
1,800


1,275

1,620


4,463

405


4,868

0
0


2 3 4

2,100 2,400 2,500
2,520 2,880 3,000


1,785

2,268


6,248

567


6,815

500
200


2,040

2,592


7,140

648


7,788

1,000
200


2,125

2,700


7,438

675


8,113

1,500
200


0 700 1,200 1,700
4,868 6,115 6,588 6,413











Treatment
1
4
2
7
5
3
8
6
9


a. Treatment
1
2
3
4
6
5
7


Total costs
that vary ($/ha)
0
300
450
550
700
900
950
1,150
1,400


Total costs
that vary (/ha)
0
38
70
83
115
128
160


760



e 700



650


25 50 75 100
Total costs that vary (S/ha)


Net benefits
($/ha)

1,990
1,900 D
2,380
1,570 D
2,790
2,620 D
2,690 D
2,810
2,870


Net benefits
(S/hal
640
692
722
704 D
735
688 D
731 D


125


Exercse 2


I Exercise 22 1












b. Treatment

4
5
2
3
1


Total costs
that vary ($/ha)

124
320
390
586
623


Net benefits
($/ha)

1,210
1,280
1,480
1,150 D
1,190 D


1,400



1,300


1,200


150 200 250 300 350
Total costs that vary ($/ha)


C.
Treatments 1, 2, and 3 are dominated. The only
nondominated treatment is 4. It is not possible to draw a
net benefit curve.


400


Exercise 22










Total costs Net benefits Marginal rate
a. Treatment that vary ($/ha) (S/ha) of return

1 0 640
137%
2 38 692
94%
3 70 722
29%
6 115 735


Total costs
b. Treatment that vary ($/ha)
4 124

5 320

2 390


Net benefits Marginal rate
(S/ha) of return
1,210
36%
1,280
286%
1,480


No marginal analysis can be done.


I Exercise 23








I Exerise 2


For recommendation domain A:

Treatment

1 2 3 4

Average yield (kg/ha) 950 1,677 1,950 2,042
Adjusted yield (kg/ha) 808 1,425 1,658 1,736
Gross benefits ($/ha) 3,434 6,056 7,047 7,378
Cost of N ($/ha) 0 468 935 1,403
Application cost (S/ha) 0 300 300 300
Total costs that vary ($/ha) 0 768 1,235 1,703
Net benefits ($/ha) 3,434 5,288 5,812 5,675

Maize field price = $4.25/kg
4.30
Field price of N = 40 = $9.35/kg
0.46


6.000


5,000

4,ooo

t 4,000


500 1,000
Total costs that vary ($/ha)








Execs 24


Total costs Net benefits Marginal rate
Treatment that vary ($1hal ($/ha) of return
1 0 3,434
241%
2 768 5,288
112%
3 1,235 5,812

4 1,703 5,675 D


a. 1) 100%
2) 50%
3) 50%
4) 100%

b. 6 months x 8% per month = 48% interest over
6 months
2 x 48% = 96%, estimate of minimum rate of return

c. 10% interest over 5 months (5/12 x 24%)
15% crop insurance
10% service charge
35% total

2 x 35% = 70%, estimate of minimum rate of return


I Exrcise 2










Treatments 2, 4, 6, 7, and 8 are dominated.

Total costs Net benefits Marginal rate
Treatment that vary ($/ha) ($/ha) of return
1 99 500
111%
3 198 610
75%
5 285 675

The recommendation is Treatment 5.

Check using residuals:

Total costs Net benefits Return
Treatment that vary ($/ha) ($/ha) required ($/ha) Residual
1 99 500 50 450
3 198 610 99 511
5 285 675 143 532*

* Maximum residual




700



0600



500





16
1fl


I Eerise26








Exercise 26B I


Treatments 4 and 7 are dominated.

Nitrogen by phosphorus experiment


Total costs
Treatment that vary


Net
benefits

800


950


100

150

175


965

1,065

1,075


a/ Farmers' practice


The marginal rate of return from (2) to (5) is 115%, which
is acceptable, but close to 100%. Researchers may want to
experiment with levels of N between 50 and 100 kg/ha and
further examine interactions with P205 at those levels.


1,100

a

S1,000

4 900
,e 900
U


800


50 100 150
Total costs that vary ($/ha)


200


Marginal rate
of return


300%

30%

200%


115%


40%










Check using residuals:

Total costs
Treatment that vary ($/ha)


Net benefits Return
($/ha) required ($1ha)


a/ Farmers' practice
* Maximum residual


I Eerise26 0


Improved variety, weed control, and fertilization can all be
recommended (e.g., Treatment 5). However, farmers may
want to test elements of the package one by one. The
results show that farmers can profitably adopt the variety
by itself. Once the variety is adopted, the next step should
be better weed control (not fertilization). As a third step,
the farmers can add fertilization to their improved variety
and weed control.


IEx eris 26


800
950
965
1,065
1,075


0
50
100
150
175


Residual
800
900
865
915*
900








I x c se 6


The marginal rate of return between (1) and (2) is below
the minimum and so (2) is not acceptable. It is then
necessary to calculate the marginal rate of return between
(1) and (3). It is only 46%, which is not acceptable, so
none of the three alternatives to the farmers' practice can
be recommended. Researchers may wish to see if they can
find less expensive insect control methods.

Check using residuals:

Total costs Net benefits Return
Treatment that vary ($/ha) ($/ha) required ($/ha) Residual
1 0 722 0 722*
2 32 730 32 698
3 35 738 35 703
4 67 752 67 685

* Maximum residual


Exercse


It is not possible to make a recommendation based on this
experiment. The farmers' practice of broadcast seeding
and 40 kg N/ha was not included in the experiment, so it
is not possible to say if the treatments test-i are really
superior to the farmers' practice.










Treatment
1 2 3 4
Data Set 1
Yield (kg/ha) 2,000 2,100 2,500 2,600
Gross field benefits (S/ha) 5,600 5,880 7,000 7,280
Total costs that vary (S/ha) 0 450 500 800
Net benefits (S/ha) 5,600 5,430 6,500 6,480

Data Set 2
Yield (kg/ha) 2,000 2,100 2,500 2,600
Gross field benefits (S/ha) 5,600 5,880 7,000 7,280
Total costs that vary (S/ha) 3,275 3,725 3,775 4,075
Net benefits ($/ha) 2,325 2,155 3,225 3,205

For both data sets:
Treatments 2 and 4 are dominated.

The differences in net benefits and costs that vary between
Treatment 1 and Treatment 3 are identical for the data
sets. Therefore the marginal rate of return is the same for
both sets and the recommendation will be the same
(Treatment 3) whether you include fixed costs or not.

Change in Change in total Marginal rate
Treatment change net benefits costs that vary of return
1 3 900 500 180%


I Exercise 27








E


Field price of maize (P) = $30 kg

Minimum rate of return (M) = .8

Change in costs that vary (ATCV) =
$6,200 $1,930 = $4,270

Change in yield (Y) is calculated by:

AY = ATCV (1 + M)
P

AY = 4270 x 1.8
30

AY = 256 kg/ha of maize, extra yield required for
change in weed control to be acceptable to
farmers


The following locations should be eliminated:

4 Farmer applied manure
7 Rotation with potatoes and heavy dose of fertilizer
9 Planted late

The average yield for locations 1, 2, 3, 5, 6, 8, and 10
should be calculated, to represent the recommendation
domain of farmers who do not use fertilizer, plant their
wheat in rotation with maize or barley, and plant in
January or February.

Treatment

1 2

Average yield (kg/ha) 1,846 3,087


Exercse 2








I Exrcs 63


T No difference in yields. Choose lower cost treatment
(T1 = zero tillage) for further experimentation.

D
DO D1
Average yield (kg/ha) 3,940 5,660
Adjusted yield (kg/ha) 3,546 5,094
Gross field benefits (S/ha) 496 713
Total costs that vary (S/ha) 17 26
Net benefits (S/ha) 479 687

687 479
Marginal rate of return = 26- 17 = 2,311%

Choose D1 (= 50,000 plants/ha) for further
experimentation.

N No difference in yields. Choose lower cost treatment
(NO = no nitrogen) for further experimentation.

P
PO PI

Average yield (kg/ha) 4,620 4,980
Adjusted yield (kg/ha) 4,158 4,482
Gross field-benefits (S/ha) 582 627
Total costs that vary (S/ha) 0 35
Net benefits (S/ha) 582 592

592 582
Marginal rate of return = 35 0 = 29%

Choose PO (no phosphorus) for further experimentation.










Net benefits for
location 1
A (2706 x .9 x 1.60) $350 = $3,547
B (3677 x .9 x 1.60) $650 = $4,645
C (4319 x .9 x 1.60) $975 = $5,244

Six lowest net benefits for each treatment:
A. Locations 5, 14, 15, 16, 20, 24
Average = $1,254

B. Locations 10, 14, 15, 17, 18, 24
Average = $1,736

C. Locations 7, 8, 14, 15, 17, 20
Average = $352

Because the minimum returns from "C" are much lower
than from either "A" or "B," it might be best to discard
"C" as being too risky. The minimum returns for "B" are
well above those of "A," so "B" would be a good
recommendation.


I Eercse 1








I Exerise 3A


Gross Total
Adjusted field costs Net Marginal
yield benefits that vary benefits rate
1. Treatment (kg/ha) ($/ha) ($/ha) ($/ha) of return

1 1,784 9,812 0 9,812
53%
2 2,564 14,102 2,803 11,299 -66%
143%
3 2,763 15,197 3,253 11,944
71%
4 3,340 18,370 5,105 13,265

If the field price of wheat is $5.50/kg, the recommendation
should be 0 kg N/ha, 0 kg P205/ha (Treatment 1).


Adjusted Gross field Total costs Net Marginal
yield benefits that vary benefits rate
2. Treatment (kg/ha) ($/ha) ($/ha) ($/ha) of return

1 1,784 13,202 0 13,202
106%
2 2,564 18,974 2,803 16,171
227%
3 2,763 20,446 3,253 17,193
131%
4 3,340 24,716 5,105 19,611

If the field price of wheat is $7.40/kg, the recommendation
should be 75 kg N/ha, 160 kg P205/ha (Treatment 4).











If opportunity cost of labor is $20/day:

One Two
weeding weedings

Average yield (kg/ha) 2,450 2,778
Adjusted yield (kg/ha) 2,205 2,500
Gross field benefits ($/ha) 3,308 3,750
Labor for weeding ($/ha) 280 480
Total costs that vary ($/ha) 280 480
Net benefits ($/ha) 3,028 3,270

3270 3028
Marginal rate of return = 480 280 = 121%


Two hand weedings can be recommended.

If opportunity cost of labor is $40/day:

One Two
weeding weedings

Average yield (kg/ha) 2,450 2,778
Adjusted yield (kg/ha) 2,205 2,500
Gross field benefits ($/ha) 3,308 3,750
Labor for weeding (S/ha) 560 960
Total costs that vary ($/ha) 560 960
Net benefits ($/ha) 2,748 2,790

2790 2748
Marginal rate of return = 960- 560 = 11%


One hand weeding can be recommended.


Exercise 32BL








I Execis 3 A I


Field price of maize:

Harvesting cost: 2



6

Shelling cost: $


Transport cost: $

Selling price in market
Harvest cost
Shelling cost
Transport cost
Field price of maize


,400 kg = 600 kg/day
4 days


$300/day
00 kg/day

300/day
500 kg


= $0.50/kg


= $0.60/kg


1.00/kg

$15.00/kg
$ 0.50/kg
$ 0.60/kg
$ 1.00/kg
$12.90/kg


Field price of fertilizers:


(Note that because the experiment is set up in terms of
bags of fertilizer there is no need to calculate field price of
nutrients.)

Field price of 10-30-10 fertilizer:


Selling price
Transport
Field price


$450/50-kg bag
$ 30/50-kg bag
$480/50-kg bag


Field price of ammonium sulfate:


Selling price
Transport
Field price


$380/50-kg bag
$ 30/50-kg bag
$410/50-kg bag








Exercse 3A


Partial budget:

Treatment

1 2 3

Average yield (kg/ha) 2,425 3,116 3,405
Adjusted yield (kg/ha) 2,304 2,960 3,235
Gross field benefits (S/ha) 29,722 38,184 41,732

Cost of seed ($/ha) 640 800 800
Cost of planting (S/ha) 600 1,050 1,050
Cost of fertilizer (S/ha) 1,370 2,190 2,190
Cost of application (S/ha) 300 600 600
Cost of insecticide (S/ha) 0 0 1,200
Cost of application ($/ha) 0 0 450

Total costs that vary (S/ha) 2,910 4,640 6,290

Net benefits (S/ha) 26,812 33,544 35,442








Exercise 33A


Marginal analysis:


Total costs Net
Treatment that vary ($/ha) benefits ($/ha)


2,910

4,640

6,290


26,812

33,544

35,442


Marginal rate
of return


389%

115%


A recommendation can be made for improved planting
density, fertilization, and insect control. In making the
recommendations, extension agents will want to
emphasize that farmers can adopt these improvements in
steps, first improving density and fertilization, and then
adopting insecticide.






35,000 1
4J

a



41J
25000
2530,000



25,000


3,000 4,000 5,000 6,000
Total costs that vary ($/ha)


7,000










Field price of N:

Urea $39.50/kg
Transport $ 3.50/kg
$42.50/kg

Field price of urea = $0.84/kg

$0.84
Field price N = 0.46 $1.83/kg

Field price of wheat:

Because the wheat harvest is charged by the hectare,
harvesting costs are fixed and do not have to be
included in the field price of wheat. Because the wheat
is purchased on the spot, $0.35/kg can be used as the
field price of wheat.

Because the statistical analysis shows no response to
seeding rate and no nitrogen by seeding rate interaction,
seeding rate should not be included in the partial budget.

There was a significant response to nitrogen, so this
should be included in an economic analysis. The best
estimate of nitrogen response will be the average yields
across all seeding rates.

Treatment
1 2 3 4

Average yield (kg/ha) 2,293 2,719 3,074 3,226
Adjusted yield (kg/ha) 1,949 2,311 2,613 2,742
Gross field benefits ($/ha) 682 809 915 960

Cost of N (S/ha) 55 110 165 220
Cost of application (S/ha) 5 5 10 10

Total costs that vary (S/ha) 60 115 175 230

Net benefits ($/ha) 622 694 740 730


I Exrc ise 33B











Total costs
Treatment that vary($/ha)


60

115

175

230


Net benefits Marginal rate
($/ha) of return


622

694

740


131%

77%


730 D


If the minimum rate of return is 80%, 60 kg N/ha
(Treatment 2) would seem to be a possible recommen-
dation and could be tested further. Experiments on
nitrogen may include higher levels of N, but the
preliminary evidence indicates that 90 kg N/ha
(Treatment 3) may not be economic.



3


700



a


1
600
60 120 180 240
Total costs that vary ($/ha)
















..... .. .. .. ...... ....
... .. .. ... ..









.. ..... ...... .


... ......
02
K. HE
'. BRI


.... ... .... .. ... ..





..... .... .. ..



.... ..... ...... ..
M Fmil N ., ............... -5,



NE:

PREI LON.: W.


... .. ........
... ... ...
. ... 1
i..

EV 1 KM'
.... .....

REM
... .... .





....... .





X X':% m .... ........


42.
......... O k

...........
.. .......
..........
'V. n.:.:
I M:x

.........











COPYRIGHT NOTICE

CIMMYT International Maize and Wheat Improvement Center

The CIMMYT International Maize and Wheat Improvement
Center holds all rights to the source text and shall be
considered the copyright holder for the text and images of
these publications.

The CIMMYT International Maize and Wheat Improvement
Center has made this publication available to the University of
Florida, for purposes of digitization and Internet distribution.

The CIMMYT International Maize and Wheat Improvement
Center reserves all rights to this publication. All uses,
excluding those made under "fair use" provisions of U.S.
Code, Title 17, Section 107 are restricted.

Contact the CIMMYT International Maize and Wheat
Improvement Center for additional information and
permissions.




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs