Conservation agriculture Tanzania_casestudy.pdf - Sokoine ...

Crop and livestock interactionLivestock is the main source of wealth, food and employment in many parts ofthe district. At present only 58,762 ha are devoted to livestock grazing, which isconsidered inadequate for the number of animals. Both zero-grazing and freerangesystems are practised. Free-range grazing is confined to the steep slopes ofMt Meru and Sakila and to the less fertile and arid areas of Mukulat and MbuguniDivisions. Most domestic livestock found in the district are indigenous, with cattle,goats and sheep making up to 60% of the total livestock production (Nyaki et al.1991). Numbers according to district records are 432,462 indigenous cattle, 326,807goats, 304,888 sheep, 136,250 donkeys, and 60,000 dairy cattle.There is much crop and livestock interaction. Many poor farmers use draught animals.Donkeys are mainly used to transport fuel, wood, water and other farm products.Animals are a manure source to many households as well as a means of incomefrom animal products. Heifer Project International has promoted dairy cattle. Thishas increased zero-grazing and diversified income through selling milk; free range isstill largely preferred despite village bylaws. Farmers practising zero-grazing use cropresidue to feed their animals and use the farmyard manure to fertilize their land. InManyire and Likamba manure is required to plant banana suckers.Soil conservationSoil conservation includes both physical measures to control runoff and biologicalmeasures. Mechanical structures include fanya juu, a technique originating fromKenya. The soil is thrown on the upper side of the 50–60-cm drain channelthat follows the contour. It can be either graded or done on a dead level contour,depending on the nature of the region (Elijah et al. 2000). Fodder crops are grownalong the contour bunds to control soil erosion where water concentrates.Contouring was promoted as early as the colonial period, when it was mandatoryfor farms to have contours. These practices have been promoted by governmentagencies through agricultural extension and development agents. Contours needconstant maintenance. Many are already losing shape and capacity to prevent soilerosion, especially the ones developed during colonial times. However, areas withcontour bunds are better off than those without contours in controlling soil erosionand reducing runoff. Making and maintaining contours is labour intensive andtime consuming, leading to their unpopularity among the farmers.Vetiver grass is planted on contours and its dense root network enables it to stop soilmovement and trap silt. The large-scale farmers in Arumeru, particularly GombaEstates Limited, use it. It has endured roaming animals and droughts, since vetiveris edible to animals only when young and is very drought resistant.Fodder grasses such as elephant grass or Napier grass and tree legumes such asLeucaena leucocephala, L. diversifolia, Calliandra calothyrus and Sesbania sesban are plantedalong contours for fodder and controlling soil. Trees are traditionally grown byfarmers, especially around Mt Meru. They provide shade, wind protection, fodderand fruit. They are planted along field boundaries, particularly around homesteads,roadsides and badly eroded areas. Live fencing is also used with species useful foranimal feed and occasionally for mulching.Arumeru District 17