Conservation agriculture Tanzania_casestudy.pdf - Sokoine ...

Soil coverProviding adequate soil cover is a cornerstone of conservation agriculture. Yet mostfarmers face great difficulties in achieving it. Farmers tend to collect residue orallow livestock herds to graze freely on crop residue. This may be an individualdecision, or it may be the result of agreements and traditions regulating therelationships between farmers and pastoralists, such as with the Maasai in northernTanzania. Producing enough biomass to cater for both adequate soil cover andlivestock demands is a challenge. Replacing a food legume used traditionally inintercropping (such as beans) by a cover crop (such as canavalia or mucuna) mightnot be attractive to a farmer whose primary objective is achieving food security. Thismay explain the success that Dolichos lablab is having with Kenyan and Tanzanianfarmers, as it is a multiple-purpose cover crop, able to provide food (both grain andleaves are edible), income, forage and soil cover.Weed controlWeed control remains a challenge, especially when farming is done manually. Asmost farmers do not manage to keep their soils adequately covered, reducing tillagetends to increase aggressive weed growth. Controlling weeds adequately, which iscritical to avoid crop failure, requires hoeing numerous times 8 or using herbicidessuch as glyphosate. For many farm families, neither option is feasible. Labourresources are scarce or expensive, or access to herbicides and sprayers is restricted.More efforts are definitely needed to identify suitable cover crops and to achieve soilcover if herbicide dependency is deemed undesirable.Equipment and inputsReduced tillage implements such as rippers and no-till seeders have been madeavailable to farmers on an experimental basis. Often implements are importedfrom Brazil. Farmers are also being helped to get specific inputs, such as herbicidesand cover crop seeds. Many farmers have restricted access to both implementsand inputs; thus they are likely to delay planting, which adversely affects yield andincome.Family labour is increasingly scarce. This situation should ultimately lead totechnologies such as reduced tillage systems, direct seeding technologies, herbicides,weed wipes or sprayers that save labour, although many farmers may not find themaccessible or affordable.Large-scale adoption of conservation agriculture practices requires a functioninginput supply chain. This means both private and public sectors must play a moreproactive role in developing local capacity for manufacturing and making availableappropriate implements and in devising innovative implement-sharing schemes(hire services, Laikipia) and adequate rural finance systems. Empowered farmersgroups are perceived as being the right entry point for making inputs and servicesavailable.8 For example, in southern Zambia conservation agriculture promoters recommendweeding four to six times.xviShetto, Owenya