Conservation agriculture Tanzania_casestudy.pdf - Sokoine ...

Executive summaryA case study was undertaken to establish experience with conservation agriculture inKaratu District by documenting its practices, achievements, challenges and gaps, andfuture aspects of these technologies in the study area. The study employed a wide rangeof methods: literature review, interviews with key conservation agriculture stakeholders,field visits, participatory rural appraisal workshops and focus group discussions.For a long time in Karatu crop production by small-scale farmers has beenperforming poorly, primarily due to inadequate rainfall, shortage of labour, drudgerybecause of using inefficient implements like hand hoes, and declining soil fertility andproductivity due to nutrient mining, soil erosion, depletion of organic matter anddestruction of soil structure leading to the formation of hardpan. Climatic conditionshave become increasingly unpredictable; precipitation has become highly erraticand the area has been subject to increasingly longer dry periods. On-site effectsof soil erosion include the loss of fertile topsoil and large fluctuations in the flowof rivers and springs, leaving behind degraded terrain. Degraded land stores lesswater, making crops vulnerable to drought, and it has a serious negative effect onthe supply of water into Lakes Manyara and Eyasi. Off-site effects of soil erosioncause pollution of water bodies, sedimentation on farmlands, and physical damage tocrops and infrastructure. There is serious concern over the increase of sedimentationin Lake Manyara, which is reducing the water depth and exposing more water toevaporation. The environmental degradation in Lake Manyara National Park, oneof the famous tourist sites in Tanzania, may affect wildlife.Workforce for farming has been declining over time as many youth find the systemused by small-scale farmers tedious with little returns and opt either to migrate totowns or to remain jobless in the village, loitering and becoming a drunkard. TheHIV/AIDS epidemic has also affected the labour supply significantly.Among the conservation agriculture practices in use are subsoiling, that is, using aMagoye ripper to break hardpan. Direct seeding in planting is done with jab plantersor hand hoes while crop rotation with lablab and wheat is practised. Some indigenousconservation agriculture practices include planting pigeon pea and pumpkin as covercrops. Cover crops such as Dolichos lablab and Mucuna are intercropped or relayed withmaize as a main crop. Practices aimed at conserving soil include establishing contours,especially on sloping areas, and agroforestry techniques for soil and water conservation.The main driving force for introducing conservation agriculture principles wasthe need to increase yield per unit area as yield continued to decline year afteryear. Research findings revealed that soil productivity was the most limiting factorwhere soil hardpan and low organic matter disrupted the soil structure, ultimatelyresulting in low moisture-holding capacity and microbial activities. Conventionalmethods of cultivation and the use of inorganic fertilizers did not solve much.The conservation agriculture entry point in Karatu aimed at counteracting thedrought circumstances by using draught-animal power and ripping through tobreak the hardpan and at the same time instituting in situ rainwater harvesting,considered a labour-saving technology.Karatu District 55