Summary of Recommendations on Tarahumara Soil, Water and Seed Resource Management
by Ruth Mendum and Ray Weil
In the five villages that the team visited, a common pattern of problems was evident. Each village had specific limitations but in general the following recommendations apply to all the locations visited.
a. Because the soil pH was generally acidic, especially on the hillsides, it may be useful to save the ashes from home cooking fires and spread them lightly but evenly over the fields, especially those farthest from the houses and with the steepest slopes. It is important to avoid dumping all the ashes in one place where the soil will then become too alkaline while the rest of the field remains too acidic. Cooking fire ash that has been protected from rain also usually contains significant amounts of the plant nutrients phosphorus, sulfur, potassium, magnesium and calcium, but little nitrogen.
b. Maize cobs should be dumped into the corrals where the animals are kept to soak up urine and compost with manure. After the materials have decomposed, they can be beneficially applied to the crop fields. Moving the corrals from time to time as was practiced to some degree in one of the villages is a useful practice and helps spread the manure.
c. All of the villages had at least one gully running through or near a maize field. Simple – but properly constructed check dams of local rock – can help stabilize the smaller gullies (up to 1 m deep) and reclaim productive land for crop production. These simple check dams need to be built to include these features:
a. The ends of the dam must be anchored into excavated notches in the sides of the gully to prevent water from cutting around the dam.
b. The center 1/3 of the dam must be lower to from a “spout” for controlled water flow.
c. A spill plate of rock must be installed below the dam to receive the water flow without allowing further cutting into the gully bottom.
d. Large rocks (that will not wash away with heavy water flow) must be used, especially for the upper layer of the dam.
e. The dam must be carefully leveled (using a simple “A”-frame or glass of water and board) to avoid allowing flow to go around one side.
f. Multiple dams must be built at suitable intervals. As a rule of thumb, the spill plate of one dam should be at the same elevation (can be checked with a level or A-frame) as the top of the next lower dam in the gully.
The larger gullies may need larger concrete-reinforced check dams.
d. A winter cover crop of vetch and rye or oats should be planted on most fields. Animals should not be allowed to graze on these fields until the vetch is well established. Even then, part of the cover crop should be protected to provide seeds for the next year. In addition, when grazing on fields, the cover crop should never be grazed to the ground. As with the natural grass pasture, the animals should be removed and the plants rested for about 4 weeks when1/3 of the plant height is left remains.
e. Optimal grazing requires a rotation of 25-30 days to allow the grass in pastures to re-grow. Adult women now control the herds with a great deal of precision. It would be helpful to consult with these women to learn their priorities and strategies for raising their animals. From there it might be possible to introduce a pilot plot on which grasses would be allowed to grow to full height protected from animals. Animals could then graze the pilot plot to 1/3 of the height of full growth, followed by a 25 day period of rest. It would be our hope that this approach would allow the women in charge of the herds to make the choice to alter their grazing habits to allow better growth in pastures.
f. In fields – or parts of fields - where the crop growth is so poor that the yield will be extremely low, crops should not be planted next year. Planting crops on these areas just accelerates the soil degradation and wastes effort and inputs would give a better return on the more fertile areas. Instead those fields should be planted with cover crops like hairy vetch and rye. If that is not possible, the fields should be allowed to lie fallow and grow weeds and natural forage, but not grazed until the best grasses can grow to their full size (just before the best grasses begin to flower).
g. Simple water diversion structures can be used in many villages to spread water over fields and ensure better irrigation of crops. Each slope requires a unique treatment that usually will involve cooperation among adjacent field holders.
h. Over the course of this growing season farmers should be encouraged to observe and mark those individual maize (or bean) plants that are growing well and those that are not. Those marked plants which were particularly healthy or produced heavily should have their cobs saved separately. Next year, the seeds from the best plants should be replanted in the most fertile spots. For example, they should be placed in a part of a field where goat manure has been spread as well as ashes. This will help to optimize yield and other positive plant characteristics.
i. The Coordination has begun an excellent initiative to grow mountain bred corn varieties on commercial farms in the valley with the intention of redistributing the seeds to mountain villages. This initiative represents a potentially vital source of quality seeds for the Tarahumara. To insure the usefulness of the project a few criteria should be observed:
i. When growing seed maize in the valley fields, care should be exercised to sufficiently isolate distinct varieties from each other.
ii. When the seeds are distributed, it should be made clear to the recipients that they should expect to save those seeds rather than plan to receive government-sponsored seeds every year. This approach will ensure that the mountain varieties stay adapted to the microclimates from whence they came. It will also allow the Coordination’s resources to stretch further and serve more communities. Additionally, it is important not to undermine seed saving practices in the villages, especially since both genetic diversity and seed saving expertise could be lost in the process.
iii. In several locations we noticed that up to eight varieties of maize were being grown. Juan Daniel is an excellent source of information about how many and what kinds of maize are grown. Optimally, each year the Coordination would grow out two new varieties obtained from the villages rather than having the Coordination save seeds for their own replanting program. While this may seem contradictory, seeds saved from one year to the next in the valley will adapt to valley conditions. At the same time, communities will be more likely to grow maize varieties that they know the Coordination is growing in case of crop failure. The overall result could be a reduction in maize diversity.
iv. It would be beneficial if small pilot plots of other grains could be grown, including amaranth which has a cultural history with the Tarahumara.
j. Drip irrigation could be helpful in those villages where there were fields being irrigated from springs. Drip irrigation could also be used to keep young trees alive on the banks of stream beds and other locations where erosion is a problem. Currently the Tarahumara told us they have access to tree stock but either lack sufficient water or the manpower to carry water to the young trees during their first two years of growth. It is also vital that grazing animals (especially goats) be kept away from young trees. Generally grazing in forested areas is also to be avoided as it is destructive to the forest and offers little fodder for the livestock.
k. In several locations we observed large scale erosion. It is possible that logging upstream from villages may be contributing to increased destruction of prime farmland for the Tarahumara. We did not have the opportunity to investigate this possibility but it might be helpful to replant and provide erosion control on lands where there has been extensive logging to protect villages downstream.