Planting Pits
Zai or tassa planting pits are a special cultivation method for degraded land.
The method involves digging holes into the ground (preferentially at the beginning of the dry season) in which plants like millet or sorghum can be sawn later on at the start of the rainy season. The pits measure between 10 and 20 cm in depth and 20 and 40 cm in diameter and are spaced approximately 1 m apart from each other. In addition to this, accruing excavated earth is formed to a small ridge downslope of each hole and, if available, organic fertilizer or compost is added to the pits. The described arrangement of the planting pits ensures an efficient collection and concentration of rainfall, runoff and nutrients and therefore makes it possible to bring degraded land back into cultivation. To optimize the situation on the fields, planting pits are often used in combination with contour stone bunds. The costs for planting pits mainly consist out of labour costs and are estimated to amount approximately 160 $ per ha.
Stone Lines / Contour Stone Bunds
The installation of contour stone bunds is a technique to minimize the erosion on cropland caused by water runoff.
Contour stone bunds (35-40 cm wide and approx. 25 cm high) are made of a mixture of small and large stones which are embedded 5 to 15 cm in the ground. They are constructed along the natural contour of the land in series behind each other, usually spaced 20-50 m apart depending on the slope of the terrain. Arranged like this, the bunds form a barrier that slows down runoff and therefore reduces erosion and increases water infiltration into the underground. In addition to this they act like a filter, trapping waterborne rich sediment particles, which results in an improved soil fertility. This effect is increased when small stones are placed at the upslope and larger stones on the downslope side of the contour bund. The costs for contour stone bunds usually lie in between 30-60 $ per ha depending on the distance to the nearest quarry.
Perhaps the greatest question when starting to introduce 'new technologies' is how to maximize the uptake or acceptance of the chosen topic/method by the stakeholders whom you wish to assist by the use of the 'new technology'.
We tend to forget that stakeholders have a never ceasing struggle to survive, that taking time to learn a 'new technology' means time spent away from the requirements of sheer survival,raising & feeding their family among other demands; thus while we (the learned teachers) strive to pass on the knowledge that we feel sure will impact the stakeholders life we miss the fact that for the most disadvantaged absorption, acceptance and utilization of any given technology rides on how quickly it will work or conversely how much time can be saved/realized by the use of a given technology/methodology.
Agriculture is by its very nature,time consuming, therefore 'improved methodologies' must reduce the time spent in cultivation OR increase the net amount harvested in the same amount of time. taking several pages from history we note that the use of charcoal as been practiced by man across civilizations & continents. from midden pits of Scotland to terra preta dos Indios man has found significant benefit from incorporation of charcoal in planting beds.
Using a trench some 2 ft deep by width of desired bed and placing a 4 inch layer of charcoal at the bottom, water & nutrient retention is dramatically improved ( the remaining space is back-filled with ordinary soil), adding a rudimentary irrigation system (4 ft lengths of bamboo with all but the bottom 'node' removed then drilled with 4 holes approximately 4 then 8 inches from the bottom of the bamboo, spaced every 4-6 ft) creates a refillable water reservoir, which slowly releases the water/nutrient tea into the charcoal & soil planting bed. Water dispersal is directly into the root system encouraging root growth-better resistance to drought- while minimizing the effects of water on leaves (fungus/virus) the result being less water used per plant, better utilization of water by plant, greater crop production as the plant is spared the dry/wet/dry syndrome so often responsible for poor yields, evaporation is significantly reduced versus drip irrigation without the maintenance requirements of drip irrigation; material is readily available at most sites and results easily observed and appreciated. Once established the beds are constantly providing the same benefits for each successive crop cycle. this method will improve yields & quality of crops under most conditions it creates a better environment than surrounding soils while needing minimal maintenance- exactly what we set out to do when we arrived 'on-site'.
We strive to refine our service delivery to stakeholders but often forget that they know what they need (even if, at times, they have difficulty in articulating the desire).
