Conservation agriculture Tanzania_casestudy.pdf - Sokoine ...

Most of the implements, except the hand hoes, pangas and slashers, have beenintroduced through conservation agriculture organizations. Small-scale farmersprefer less costly and uncomplicated equipment, such as jab planters, hand hoes andanimal-drawn rippers. Most conservation agriculture equipment was provided byprojects. This has led to sharing equipment, especially the animal-drawn ripper andthe direct seeder. If one is not available, farmers use hand implements to turn thesoil. Artisans who have been trained by the rural development project to maintainimplements assist in making them. The first locally produced rippers could notreach the required depth. Local artisans adjusted them.Subsoilers were introduced to both small- and large-scale farmers. The soilconservation programme demonstrated the Palabana subsoiler, widely used inZambia. The farmer service centre hired out their subsoilers at TZS 13,000 per hour,according to their 2003 price list, a cost most small-scale farmers could not afford,limiting their use. Large-scale farmers preferred to use subsoilers and benefit fromthe saving in fuel and labour. Animal-drawn subsoilers have just been introduced inthe district by the CASARD project, so little information is available.Ripping has been promoted and is done before the onset of rains to harvestrainwater. It is mainly done with a draught animal and is 30 cm deep, leavingripped lines to sow seeds with hand hoes and jab planters. This allows for propertiming with the rains.Minimum tillage aims to reduce soil erosion by using hand hoes, ripping, herbicides,direct planters and, for large-scale farmers, chisel ploughing. Zamwipes have notbeen widely adopted and institutions, especially SARI, are still demonstratingthem. Ripping has been promoted by institutions since 1998 in Arumeru District,but adoption has been slow. This can be attributed to uncoordinated efforts bystakeholders, lack of available equipment, especially after projects are phased out,and few trained artisans.Soil coverVarious cover crops have been introduced to maintain soil moisture, reduce runoff,increase infiltration, reduce erosion, and increase or maintain organic matterthroughout the year. Some farmers growing bananas have adopted grass strips andonly dig holes to plant the suckers and mulch with crop residue.In Arumeru District the cover crop choice usually depends on whether the crop canbe eaten as much as on its capacity to improve soil fertility, conserve soil moistureand increase soil organic matter. Because lablab, pigeon pea and pumpkin areedible they are secure in their inclusion as cover crops in Arumeru District.Good cover crops suppress weeds. In Manyire, intercropping is done after twoweeks and total cover is attained after four weeks. Permanent soil cover is still achallenge. During drought the cover crop competes for moisture with the maincrop. Livestock competes for the crop residue with free grazing. The maize stoveris used as fuel. Pests invade lablab. Conservation agriculture farmers struggle withthese challenges to maintain soil cover. Yet they do cover their soil, mainly fromcrop residue and from weeds uprooted and left to dry and die on the field rather24 Maguzu et al.