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close this bookSoils, Crops and Fertilizer Use: A Field Manual for Development Workers (Peace Corps, 1986, 338 p.)
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.