Cover Image
close this bookSoils, Crops and Fertilizer Use: A Field Manual for Development Workers (Peace Corps, 1986, 338 p.)
View the document(introduction...)
View the documentAbout this manual
View the documentAcknowledgements
close this folderChapter 1: Down to earth - Some Important Soil Basics
View the documentWhat is soil, anyway?
View the documentWhy do soils vary so much?
View the documentTopsoil vs. subsoil
View the documentThe mineral side of soil: sand, silt, and clay
View the documentDistinguishing ''tropical'' soils from ''temperate'' soils
View the documentOrganic matter - a soil's best friend
View the documentThe role of soil microorganisms
close this folderChapter 2: Trouble-shooting soil physical problems
View the document(introduction...)
View the documentGetting to know the soils in your area
View the documentSoil color
View the documentSoil texture
View the documentSoil tilth
View the documentSoil water-holding capacity
View the documentSoil drainage
View the documentSoil depth
View the documentSoil slope
close this folderChapter 3: Basic soil conservation practices
View the document(introduction...)
View the documentRainfall erosion
View the documentWind erosion
close this folderChapter 4: Seedbed preparation
View the document(introduction...)
View the documentThe what and why of tillage
View the documentCommon tillage equipment
View the documentThe abuses of tillage and how to avoid them
View the documentMaking the right seedbed for the crop, soil, and climate
View the documentHow deep should land be tilled?
View the documentHow fine a seedbed?
View the documentSome handy seedbed skills for intensive vegetable production
close this folderChapter 5: Watering vegetables: When? How Often? How Much?
View the document(introduction...)
View the documentIt pays to use water wisely
View the documentSome common watering mistakes and their effects
View the documentFactors influencing plant water needs
View the documentOk, so get to the point! how much water do plants need and how often?
View the documentSome methods for improving water use efficiency
close this folderChapter 6: Soil fertility and plant nutrition simplified
View the document(introduction...)
View the documentLet's Make a Deal
View the documentHow plants grow
View the documentAvailable vs. unavailable forms of mineral nutrients
View the documentSoil negative charge and nutrient holding ability
View the documentSoil pH and how it affects crops growth
View the documentImportant facts on the plant nutrients
close this folderChapter 7: Evaluating a soil's fertility
View the document(introduction...)
View the documentSoil testing
View the documentPlant tissue testing
View the documentFertilizer trials
View the documentUsing visual ''hunger signs''
close this folderChapter 8: Using organic fertilizers and soil conditioners
View the documentWhat are organic fertilizers?
View the documentOrganic vs. chemical fertilizers: which are best?
View the documentSome examples of successful farming using organic fertilizers
View the documentHow to use organic fertilizers and soil conditioners
close this folderChapter 9: Using chemical fertilizers
View the document(introduction...)
View the documentWhat are chemical fertilizers?
View the documentAre chemical fertilizers appropriate for limited-resource farmers?
View the documentAn introduction to chemical fertilizers
View the documentCommon chemical fertilizers and their characteristics
View the documentThe effect of fertilizers on soil pH
View the documentFertilizer salt index and ''burn'' potential
View the documentBasic application principles for N, P, and K
View the documentFertilizer application methods explained and compared
View the documentTroubleshooting faulty fertilizer practices
View the documentGetting the most out of fertilizer use: crop management as an integrated system
View the documentUnderstanding fertilizer math
close this folderChapter 10: Fertilizer guidelines for specific crops
View the document(introduction...)
View the documentCereals
View the documentPulses (grain legumes)
View the documentRoot crops
View the documentVegetables
View the documentTropical fruit crops
View the documentTropical pastures
close this folderChapter 11: Liming soils
View the document(introduction...)
View the documentThe purpose of liming
View the documentWhen is liming needed?
View the documentHow to measure soil pH
View the documentHow to calculate the actual amount of lime needed
View the documentHow and when to lime
View the documentDon't overlime!
close this folderChapter 12: Salinity and alkalinity problems
View the document(introduction...)
View the documentHow salinity and alkalinity harm crop growth
View the documentLab diagnosis of salinity and alkalinity
close this folderAppendixes
View the documentAppendix A: Useful measurements and conversions
View the documentAppendix B: How to determine soil moisture content
View the documentAppendix C: Spacing guide for contour ditches and other erosion barriers*
View the documentAppendix D: Composition of common chemical fertilizers
View the documentAppendix E: Hunger signs in common crops
View the documentAppendix F: Legumes for green manuring and cover-cropping in tropical and subtropical regions
View the documentAppendix G: Some sources of technical support
View the documentAppendix H: A bibliography of useful references

Appendix C: Spacing guide for contour ditches and other erosion barriers*


(See Chapter 3)

% SLOPE

DEGREESSLOPE

DISTANCE BETWEEN DITCHES** IN METERS

5

21.6

6


19.3

7

17.7

8


16.6

9

15.8

10


15.0

11

14.2

12

13.4

13


12.7

14

12.1

15


11.5

16

11.0

17


10.5

18

10º

10.0

19


9.5

20

11°

9.0

21


8.6

22


8.2

23


7.8

24


7.5

25

14°

7.2

26


7.0

27


6.7

28


6.4

29


6.2

30

17°

6.0

31


5.8

32


5.6

33


5.4

34


5.2

35

19°

6.0

36


4.9

37


4.8

38


4.7

39


4.6

40

22º

4.5

41


4.4

42


4.3

43


4.3

44


4.1

45

24°

4.0

* These spacings are suitable for contour ditches, rock walls, and other erosion barriers.

** The distances in column 3 are based on Peace Corps project experience in El Salvador. Check with conservation specialists in your region for their recommendations.