Grass strips measuring 0.80 m to 1 m wide are planted 20 to 80 m apart on low-gradient terrain. Local grasses (for example, Andropogon gayanus, Cymbopogon schoenateus and Vetivera nigritiana) are sown or planted (plantlets) at the start of the rainy season. Like stone bunds, grass strips are planted along the natural contour of the land to slow down runoff, increase infiltration and retain sediment. Grass strips get bigger as sediment builds up, which maintains their capacity to retain water, unlike mechanical structures (stone bunds and dikes).
The species of grass are chosen according to what the farmers want to use them for (straw, hay, mat weaving, roofing, construction of straw granaries, brooms, etc.). In cattle and sheep raising areas, the use of fodder plants can increase interest in this technique and ensure wider acceptance. It is recommended that the development of grass strips be combined with assisted natural regeneration (woody species) or the planting of trees.
Designed as an erosion control measure, grass strips slow down runoff in the event of heavy rain. They distribute rainwater more evenly over the land and improve infiltration which is particularly important when there are dry spells in the rainy season. Sediment builds up behind the grass strips, thereby reducing the erosion of fertile soil layers. The roots of the plants bind the soil and hold it in place. Although the vegetation growing in the strips competes with the crops to some extent for water, the overall effect on yields is positive. Crops are also protected from wind erosion. Thanks to the vegetation cover they provide, grass strips contribute to lowering soil temperature.
Like contour stone bunds, grass strips reduce the harmful effects of heavy rain and violent downpours, events that are expected to increase as a result of climate change.
Compared with plots without grass strips, millet yields were 50 kg per hectare per year higher, and straw yields 125 kg higher on plots with grass strips. Yields can be substantially improved by combining grass strips with the application of organic fertiliser, mulch or pen manure. The best results, an average increase of 280 kg of millet grain per hectare (370 kg of straw per hectare), were achieved by combining them with mulching and pen manuring. Grass strips therefore improve yields of cereals and forage for livestock (straw and grass growing on the strips).
Increased crop output increases household food security and improves livestock feeding. The straw cut on the grass strips can also be used for other purposes (fencing and roofing). It is also a source of income, as traditional products made with straw, such as woven mats, can be sold.
Grass growth tends to be patchy, and resowing is required several times to fill in the gaps in the strip. In order to protect the grass strips from grazing animals during the first year, it is recommended that the area be monitored, which requires strict control over the village herds and flocks and those of nomadic livestock keepers.
Some grasses tend to invade crop fields. It is therefore important to control them by cutting them down before they flower and to tend the strips regularly, straightening and cutting back the edges.
Any dead plants in the grass strips must be regularly replaced. Grass strips are more likely to be maintained if they are economically profitable, for example, if they produce hay for livestock or their output can be sold as forage or construction material.
It is a technique designed mainly for cropland, but can also be used on rangeland, provided that the plants are protected when the grass strips are put in place. Grass strips are suitable for areas in the Sahel and the Sudan with rainfall ranging between 400 and 1,000 mm/year and gently sloping terrain (< 2%). Ecological units that benefit from the implementation of this measure include dune land, pediments and plains (highland pediments). Grass strips are particularly appropriate for non-stony land in areas with higher rainfall levels.
الموقع: Filingué, Ouallam, Tillabéri, Tera, Niger, النيجر
عدد مواقع تنفيذ التقنيةالتي تم تحليلها:
انتشار التقنية: منتشرة بالتساوي على مساحة (approx. 100-10 كم2)
في منطقة محمية بشكل دائم؟:
تاريخ التنفيذ: منذ 10-50 سنة
نوع التقديم
تحديد المدخلات | الوحدة | الكمية | التكاليف لكل وحدة (CFA Franc) | إجمالي التكاليف لكل مدخل (CFA Franc) | % من التكاليف التي يتحملها مستخدمو الأراضي |
العمالة | |||||
labour | ha | 1,0 | 46,7 | 46,7 | 100,0 |
المواد النباتية | |||||
seeds | ha | 1,0 | 3,3 | 3,3 | 100,0 |
إجمالي تكاليف إنشاء التقنية | 50.0 | ||||
إجمالي تكاليف إنشاء التقنية بالدولار الأمريكي | 50.0 |
Part of the plot is taken up by the grass strips, reducing the area left for growing crops
Increased crop output increases household food security and improves livestock feeding. The straw cut on the grass strips can also be used for other purposes (fencing and roofing). It is also a source of income, as traditional products made with straw, such as woven mats, can be sold.