![]() | Soil Conservation Techniques for Hillside Farms (Peace Corps, 1986, 96 p.) |
![]() | ![]() | Conclusion |
This guide attempts to provide agricultural extensionist with an understanding of some techniques which have been found helpful in improving hillside farming systems. Hopefully each extensionist can find one or several techniques presented here which are appropriate for any specific work area. Clearly it is not the role of this guide, just as it is not the role of the extensionist, to dictate the techniques to be used in any given situation. Rather agricultural extensionist and farmers should realize the realm of possible techniques available to them, enabling them to formulate their own plans according to the many variables (climate, topography, labor, markets, etc.) which determine the appropriateness of any given farming practice for an area.
Furthermore it is hoped that hillside farms are not to be regarded as "things to be fixed once and for all" with a set of soil conservation techniques. Farms, like individuals and communities never reach an ideal state of development, rather they are dynamic units which must adjust over time to a changing climate of environmental, human, economic, and political factors; all of which require that new practices constantly be tested and evaluated. If agricultural extensionists can communicate to farmers the importance of testing and evaluating new techniques, such as the ones included in this guide and many others, then both will be better prepared to address the problems facing the farmers now and in the future.
The technologies described in this guide are all simple options available to small-scale hillside farmers in the use of their land. It is hoped that through the use of these practices that better yields may be sustained for more years on each cultivated plot of land. In addition to the increase in crop production, the introduction of soil conservation techniques may facilitate the promotion and realization of more long-term effects of area wide conservation programs; such as the management of watersheds to maintain a reliable, clean, drinking water supply and the protection of undisturbed lands as reservoirs of native flora and fauna.
Agpada, A. et. al. 1975. Manual of Reforestation and Erosion Control for the Philippines. Compiled by H. J. Weidelf. German Agency for Technical Cooperation Ltd. Eschborn, W. Germany.
Bunch, Roland. Two Ears of Corn: A Guide to People-Centered Agricultural Improvement. 2nd Edition. World Neighbors, Oklahoma City. 1985.
Duke, J. A. Handbook of Legumes of World Economic Importance. Plenum Press, N. Y. 1981.
Firewood Crops: Shrub and Tree Species for Energy Production (2 vol.) National Academy of Sciences. Washington, D.C. Vol. 1. 1981 Vol. 2, 1983.
Gibbons, Michael J. and Schroeder, Richard. 1983. Agricultural Extension Manual. M-18. Peace Corps Information Collection and Exchange.
Greenland, D.J. and R. Lal (eds.) Soil Conservation and Management in the Humid Tropics. John Wiley and Sons, New York. 1977.
Hudson, Norman. Soil Conservation. 2nd Edition. Cornell Univ. Press, Ithaca, N. Y. 1981.
Kunkle, S. H. and J. L. Thames (eds). 1977. Guidelines for Watershed Management. Conservation Guide #1. FAO, Rome,
Leonard, Dave. 1969. Soils, Crops, and Fertilizer Use: A Guide for Peace Corps Volunteers. Peace Corps Program and Training Journal Reprint Series No. 8.
Lionberger, H. F. and P. H. Gain. Communication Strategies: A guide for Agricultural Change Agents. The Interstate Printers and Publishers Inc. Denville, Illinois. 1982.
Michaelson, Tage. 1980. Manual de Conservacie Suelos pare Tierras de Ladera. Ordenacintegrada de Cuencas Hidrogrcas. Proyecto PNUD/FAO/HOND/77/006. Tegocigalpa, Honduras.
Rodale, J. I. (ed.) The Encyclopedia of Organic Gardening. Rodale Books, Inc. Emmaus, Pennsylvania. 1971.
Rogers, E. M. and F. F. Shoemaker. Communication of Innovations: A Cross Cultural Approach. 2nd Edition. The Free Press, MacMillan Publishing Co., New York. 1971.
Sheng, T.C. and H. R. Stennett. 1975. Forestry Development and Watershed Management in the Upland Regions: Jamaica, Lecture Notes: Watershed Management and Soil Conservation Training Course. United Nations Development Programme, FAO, Kingston.
Soil Conservation Service. A Manual on Conservation of Soil and Water. United States Department of Agriculture. Agriculture Handbook No.61, 1954. Reprint R-38. Peace Corps Information Collection and Exchange. Manual M-38. September, 1982.
Suarez de Castro, Fernando. Conservacie Suelos. Instituto Interamericano de Ciencias Agrlas, San Jose, Costa Rica. 1980.
Tracy, Frederick and Ricardo Perez. 1986. Conservacie Suelos. Folleto de Campo: Distanciamientos y Dimensiones de Obras Fcas. Proyecto Manejo de Recursos Naturales, SAN/AID #5220168. Tegucigalpa, Honduras.
1986. Manual Practico de Conservacie Suelos. Proyecto
Manejo de Recursos Naturales. SAN/AID #522-0168. Tegucigalpa, Honduras.
Tropical Legumes, Resources for the Future. National Academy of Sciences. Washington, D.C. 1979.
Vickery, Deborah and Vickery, James. 1981. Intensive Vegetable Gardening for Profit and Self-Sufficiency. Peace Corps Information Collection and Exchange. Reprint R-25.
Werner, David and Bill Bower. Helping Health Workers Learn: A Book of Methods, Aids and Ideas for Instructors at the Village Level. The Hesperian Foundation. Palo Alto, California. 1982.
APPENDIX 1
A-frame level |
nivel tipo "A" |
bench terrace |
terraza de banco |
check dam |
barrera |
compost |
abono orgco |
compost pile |
abonera |
contour barrier |
berrera al contorno |
contour furrow |
surco al contorno |
cover crop |
cultivo de cobertura |
crop residues |
rastrojos, residuos |
dead barrier |
barrera muerta |
desertification |
desertificacidesertizaci/TD> |
discontinuous narrow terrace |
acequia de ladera, terraza de |
(orchard terrace) |
huerta, terraza angosta |
drainage |
desagua o drenaje |
drop box |
caja disipadora |
earthworm |
lambriz de tierra |
earthworm house |
lombricero |
eroded land |
tierra erosionada, sierra cansada |
erosion |
erosi/TD> |
fertilizer |
fertilizante, abono |
grass lined drainage canal |
canal de desague engramado |
green manure |
abono verde |
gully |
cava |
hillside |
ladera |
hillside ditch (channel terrace) |
zanja o acequia de ladera |
individual terrace |
terraza individual |
infiltration |
infiltraci/TD> |
line level |
nivel de cuerda o de aIbanil |
live barrier |
barrera viva |
manure |
estiercol |
minimum tillage |
labranza minima |
mixed barrier |
barrera mixta |
milch |
cobertura |
planting bed |
came o arriate |
point row |
surco muerto |
retention well |
pozo de retenti/TD> |
riser (terrace bank) |
talud |
rock lined drainage canal |
canal de desague empedrado |
rock wall |
muro de piedra |
runoff |
escurrimiento, ague de escorrentia |
slash and burn |
roza y quema |
slope |
pendiente, desnivel |
stormwater drain(uppermost of series of contour ditches) |
cabecera |
windbreak |
barrera rompeviento |
APPENDIX 2
1. a. Slope less than 12% or greater than 60% |
2 |
b. Slope between 12% and 60% |
3 |
2. a. Slope less than 12% |
Live Barriers and Agronomic |
Measures* b. Slope greater than 60% ..Reforestation | |
3. a. Slope between 12% and 50% |
4 |
b. Slope between 50% and 60%.Perennial Crops Using Discontinuous Narrow terraces | |
4. a. Terrain with little or no rocks |
5 |
b. Terrain with abundant rocks . |
Rock Wall Barriers and Agronomic Measures* |
5. a. Annual crops (basic grains, vegetables tubers, flowers) or bananas |
6 |
b. The majority of the fruit trees . (citrus, coffee, cacao, etc.) |
Individual Terraces with Discontinuous Narrow Terraces or Hillside Ditches |
6. a. Deep soil (greater than 1 meter) |
7 |
b. Shallow soil (less than 50 cm) |
8 |
7. a. Non-irrigated |
8 |
b. Irrigated . |
Continuous Bench Terraces and Agronomic Measures* |
8. a. Slope between 12% and 30%, and soil. greater than 50 cm |
Discontinuous Narrow Terraces depth with Agronomic Measures* |
b. Slope between 12% and 50%, or soil |
Hillside Ditches with Agrodepth less than 50 Agronomic Measures |
* Agronomic measures refer to other land management practices, such as contour plowing and planting, mulching, etc. which may be appropriate to the area.
From: Manual Prico de Conservacie Suelos, Tracy and Perez, 1986.
Reprinted with author's permission, translated by C. Crozier.
APPENDIX 3
Many non-traditional agricultural techniques require a greater investment in labor and/or fertilizers, seeds, pesticides, etc. than the traditional techniques they are designed to replace. me extra labor and expenses incurred discourage many farmers from changing their traditional methods.
In order to illustrate the changes which a small family farm operation might experience, data are presented here representing average expenses and earnings of 50 farmers. The data were collected in Santa Cruz, El Para, Honduras, the year before (1982) and the first year (1983) in which techniques of soil conservation, fertilizer use, improved corn seed varieties, and chemical pest control were introduced to a group of local farmers by Rory William Steinke, a Peace Corps Volunteer. m e farms involved in this project were all small (1 Mz =.68 ha), with slopes ranging from 10-50%. They were planted with corn and beans, the traditional crops in this area. Because of the nature of this group, these data are probably not applicable to other cultivation systems such as vegetables or fruit trees, but they do provide insight into questions which may be important to extentionists working with other systems.
TABLE 8 RESULTS OF THE SANTA CRUZ
EXTENSON PROJECT:FARM EXPENSES AND EARNINGS PER MANZANA (0.68 hectare)
TABLE 8 (Continued)
The expense accounts reveal several points which should be considered by the extensionists when advising farmers:
-These farms are heavily dependent on family labor. (Note net losses when all labor costs are included). Therefore designing a conservation plan that can be carried out without hiring out additional labor is important.
-The market price available to farmers determines whether or not the extra expenses are profitable in the short run. Due to seasonal variations in grain prices, profits are much higher if grains can be stored and sold when prices rise (in this case approximately 6-8 months after time of peak harvest).
-Once the soil conservation practices are in place however, future years' labor expenses will decrease and a greater likelihood of sustained yields increases the profitability of the modern techniques in the long run.
The use of organic fertilizers may reduce the amount of chemical fertilizer needed and avoid some expenses.
-Limiting the first year's work to a smaller plot (1/4 1/2 Mz) can greatly reduce the risk incurred and can be helpful in promoting the techniques in new areas.
APPENDIX 4
In many areas, sophisticated surveying levels are not available to farmers interested in designing soil conservation structures. Even where they are available, it is often more practical for the farmer to build a cheap, simple, effective level for use in surveying contour lines. Although less accurate than more sophisticated levels, the two levels presented here' when properly constructed and used are sufficiently accurate for the work an small hillside farms requiring measurements of 0% or 1% slope described in this guide.
Fig. 39. A-Frame level for surveying
contour lines.
A-frame level:
1. Construction:
The materials required are 3 straight boards or sticks, 3 nails or screws, a thin string, and a screw-capped glass bottle or uniform shaped rock. A small line level is very convenient and makes use much easier on windy days.
Important points to consider in building the A-frame level:
-The symmetry of the level is important (2 legs should be same length and crossbar should be positioned identically on the legs so that it is parallel to the ground.-The dimensions of the level are not important, but if constructed much larger than the one pictured, they should be assembled with screws so that they can be disassembled for transportation. Measuring an exact distance (i.e. 2m ) between the feet makes calibrating the 1% contour position easier.
-The plumb bob must be attached so that it does not deflect the string to either side. If a screwcap bottle is used, it should be hung by a hole made exactly in the center of the cap. If a rock is used, it is important that a very uniformly shaped rock be chosen.
2. Calibration:
The level should be calibrated every day before use, as warping of the wood can greatly change the results. a. Calibration of 0%
1. The level should be positioned with both feet on firm surfaces but with one end obviously higher than the other.
2. The level is gently rocked, allowing the string with the plumb bob to gently strike the cross bar,
3. When the plumb bob stops swaying side to side and the string strikes the cross bar at the same point repeatedly (510 times), mark this position in pencil on the cross bar.
4. Reverse the position of the level so that the other foot is now at the higher point. Care must be taken to position the feet of the level in exactly the same points as before.
5. Repeat steps 2 and 3, obtaining a second mark on the other side of the center of the cross bar.
6. The 0% position of the level is exactly in between the two marks obtained in this trial. m is position can be marked by measuring with a ruler or paper (1/2 the distance between the 2 marks). Now when the feet of the level are even the string will strike the cross bar at the 0% position which is used to survey contour lines for barriers, terraces or ditches which are to be used for retention, rather than diversion of water.
7. Once calibrated, a small carpenter's or line level can be fastened to the cross bar to facilitate use on windy days.
b. Calibration of 1%
1. Position the level so that the feet are an the same level and
the string strikes the cross bar at the 0% position. me feet should be an firm
surfaces.
2. Raise one foot by the distance required to position the level at
a 1% slope. For example, if the distance between the feet is 2m, then a 2 cm.
tall object or 2 cm. tall stack of coins should be placed under one foot.
(2cm/200 cm = .01 = 1%)
3. Rock the level gently, now the string strikes the 1% slope position Mark this position an the crossbar.
4. Since this type of contour line will be used to construct structures to divert water, an arrow should be placed pointing toward the rawer foot to indicate the direction of water flow
5. As in the previous calibration, if desired a small level can be fastened to the cross bar.
3. Use of the A-Frame level:
The A-Frame level is used to survey contour lines by placing stakes at the position of the feet when the level gives the desired reading. Stakes should all be placed an the same side of the level, all upslope or all downslope, in order to avoid errors. When not being used the level should be stored in a dry, shady place.
Fig. 40. Simple line level for
surveying contour lines.
1. Construction:
The materials required are 2 straight boards or sticks, a string of desired length and a line level.
2. Calibration:
The level should be calibrated every day before using as bending of the hooks on the line level or warping or chipping of the sticks can greatly change the results. a. Calibration of 0%
1. Slots are cut in each stick at the same distance from one end.
2. The string is tied firmly to each stick so that it cannot slip out of the slots.
3. Hook the line level on the string and find a place on firm ground which gives a level reading.
4. Reverse the direction of the line level on the string while maintaining the position of the sticks. If the reading changes, the hocks of the line level must he adjusted slightly by bending them.
5. Repeat steps 3 and 4 until the line level gives identical readings upon reversal.
b. Calibration of 1%
1. Repeat the steps as in the calibration of 0%. However this
time the slots on the sticks should be placed so that a 1% drop occurs over the
distance of the string. (example: if the string measures 2m then the slot on one
stick should be 2 cm higher than on the other).
2. Remember that the stick
which has the slot located higher up actually represents the lower ground
surface when the reading of the string is level. Remember to mark the sticks so
that no confusion as to the direction of water flow will arise when surveying
contour lines.
c. Use
This type of level is easiest to use with. a least 3 people, two holding the sticks and the third reading the line level and placing slakes. When not in use the line level should be protected so that the glass vial and hooks are not damaged.
APPENDIX 5
One of the main problems faced by agricultural extensionists is gaining credibillity in a community. People are often unwilling to invest time or money to try new techniques that they do not understand, solely based on the word of an outsider. m e following demonstrations can help farmers understand more about their soils and how they might benefit by changing some of their traditional agricultural practices.
Fig. 41. Demonstrating erosive power
of raindrop impact
As water is dropped on the soil next to a piece of white paper, soil particles are dislodged and splash onto the paper. This demonstration done over a mulch-protected soil results in no dislodging of soil particles. This illustrates the value of a permanent ground cover or mulch in the prevention of soil erosion.
Fig. 42. Demonstrating the advantage
of contour cultivation practices over traditional agricultural methods.
Form two mounds of soil and scratch contour furrows in one and furrows straight up and down on the other. When watered, the mound with contour. furrows should erode less than the other mound.
This demonstration can be used to stress the importance of working the land along the contour. A trial run should be made before the actual demonstration to determine the appropriate watering intensity.
Fig. 43. Demonstrating the particulate
makeup of soils
Place soil in a bottle, add water, shake, and set on a stable level surface. The heavier sand-sized particles will settle out first followed by silt-sized and then clay-sized particles. This demonstration illustrates the particulate nature of soils and can be used to help farmers understand what soil texture means and how it can be important in affecting the drainage or erodability of a soil. The bottles should be allowed to remain undisturbed for a full day in order for the finer, clay-sized particles to settle out.
Fig. 44. Demonstrating soil profiles
By digging soil pits at the spots indicated in different parts of a field, the results of past erosion can be seen. The much thinner layers of the more fertile A and B horizons on the more steeply sloped areas can be helpful in explaining the need to introduce soil conservation measures.
Fig. 45. Growth trials in soils of
varying fertility.
Planting of 3-5 corn seeds in cans containing soils from different horizons or from eroded and non-eroded parts of the same field can demonstrate the difference in fertility between upper and lower soil horizons and the value of protecting the upper soil horizon from erosion. This demonstration requires 36 weeks to show best results.
Fig. 46. Growth trails using chemical
and organic fertilizers.
Similar to number 5, this demonstration can be used to show the benefits of using different techniques to maintain or increase soil fertility. Again 3-6 weeks are required for best results.
Growth trials such as the ones shown here can be carried out to show an unlimited number of comparisons. It might also be valuable to try mulched soil, repeatedly burned soil, waterlogged soil, another crop which could be grown to maturity (beans, radishes, carrots), etc.