Conservation agriculture Tanzania_casestudy.pdf - Sokoine ...

Farmers were advised to slash the crop residues using the slasher, machete or billhook(nyengo) one month before sowing. Cutting them earlier risks fast decomposition andestablishing weeds. Dry seeding is recommended, and when this is done, there areno weeds. However, when there is a delay and seeding has to be done when weedshave already germinated, it is recommended to kill them with glyphosate two to fivedays before planting.Crop rotationCrop rotation was not common in the study area, presumably from limitedknowledge and the extensive intercropping practised by farmers. However, a fewfarmers rotated maize intercropped with beans and with sunflower intercroppedwith cowpeas. Bambara nut was normally grown on the least fertile soil that couldno longer support the maize and sunflower rotations.Indigenous conservation agricultureComponents of conservation agriculture have been practised by farmers in thesouthern highlands of Tanzania for generations. Planting with minimal soildisturbance has been traditional practice in the drier areas of Iringa, Njombe,Mbeya and Chunya Districts, to save labour and enhance planting timeliness. Inthe traditional kukomolea and kuberega systems, a planting stick, dibbler, or a hand hoewould make planting holes in the unploughed soil at the onset of the rains. Handhoeing or animal-drawn weeding would follow, in addition to mixed cropping witha legume, such as beans, cowpea or lablab. After the grains were harvested, freerangegrazing livestock or bush fires would destroy the soil cover. The little cropresidue left would be collected and burned a short time before the rains. In thefollowing season, the system started over.Faidherbia albida, locally known as mpogoro, is an indigenous legume tree that growswell in Wanging’ombe. It is recognized for its soil-enriching properties when grownin the field with other crops. It sheds its leaves during the rainy season when cropsare in the field and grows new ones in the dry season. Farmers would maintainit if it reseeded in their fields, but they did not know how to raise the seedlings.Farmers learned how to scarify seeds to enhance germination along with nurserymanagement under the agroforestry component of the soil fertility initiative ofMAFS. Farmers are now raising their own Faidherbia albida seedlings and growingthem in their fields.Mulching and no-tilling in the coffee and banana farming system in the highrainfallRungwe District of Mbeya is the only successful indigenous conservationagriculture practice in the zone. Maize, beans, taro and horticultural crops areintercropped with coffee and bananas. Planting holes are made with the hand hoe,and the few weeds that emerge from the banana leaf and chopped old pseudostemsoil cover were hand pulled or cut with the hoe. Fertility is maintained by applyingkitchen refuse, mulch and manure. However, this farming system has not attractedresearch. Different interventions are presented in appendix 3.Mbeya District 125