In Tanzania, conservation agriculture has been in practice for many years ago albeit in some areas it is still in adoption stage (Kimaro et al. 2015). Agronomic practices such as mulching, crop rotation, terraces, no-tillage and agroforestry to mention few are the most applicable soil organic management practices in Tanzania representing conservation agriculture. Maize, millet and sorghum are good example of crops involved in conservation agriculture because their straws are recommendable in organic matter formation (Partey et al. 2011). There are spatial differences in the principles and types of conservation agriculture in different regions of the country. Dodoma, Manyara and Arusha are good examples of the region where conservation agriculture is well adopted and has brought significant contribution to crop yields. Findings show that in Karatu District (Manyara Region) conservation agriculture has improved food security protected ecosystems. In Dodoma Region the use of large pits locally called chololo pits have significant contribution to maize, sorghum and millet production (Sosoveli et al. 1999).
Some of the existing conservational agricultural processes are indigenous based (Indigenous Knowledge). These include Organic farming in Ukara Island (Mwanza region), Rotational grazing in (Arusha region), Matengo Pits or Ngoro system in (Ruvuma region). Ngitiri pasture conservation (Shinyanga and Mwanza regions), Terracing and contouring (Arusha, Kilimanjaro, Tanga and Morogoro regions), Mounds and ridges in Rukwa region, Stone barriers on slopes in Korogwe district (Tanga region), Intercropping with trees (Arusha and Kilimanjaro regions), These managements of conservational agriculture have tremendous contribution to the conservation of soil fertility (He et al. 2015; Liaudanskiene et al. 2013). However, these practices are insufficient to curb food insecurity in Tanzania (FAO 2012). The rate of adopting conservation agriculture in Tanzania has a temporal and spatial variation. In areas with stressed environment are likely to adopt than those with less environmental stress. Central and northern parts of Tanzania seem to have implemented more conservation agriculture than other parts probably because they are in semi-arid (Branca et al. 2013). A number of projects have been done in those areas to stimulate and in still a sense of conservation agriculture adoption. According to the report by FAO (2006) about 85 % of farmers had adopted conservation agriculture practices to meet the aims of Sustainable Agriculture and Rural Development project (SARD).
The majority farmers were having about 0.2 hectares under conservation agriculture (Shetto and Owenya 2007). Some farmers adopted reduced tillage in a small area (20 × 20 m) while other adopted live cover crops (dolices lablab or mucuna) in slight large area compared to the former. In the southern highlands, planting basins has been adopted by farmers facilitated by projects like Southern Agricultural Growth Corridor (SAGCOT). In Arusha about 60 % of the farmers have as well adopted planting basins as conservation agriculture. This helps to retain water around the plant root for long and reduce the magnitude of crop drying and wilting during dry season (Lobell and Burke 2008). Subsequently, about 70 % of farmers have adopted organic fertilization (crop straw and animal manure) in the area. Crop residues are left in the farm after harvest to allow soil decomposition and fertilization (Kimaro et al. 2015). Burning and grazing in the harvested farm is not allowed. This has happened even in some pastoralist societies. Thus, further adoption of conservation agriculture practices should be encouraged.
The authors conclude that Conservation agriculture has been in practice in Tanzania land for a long time. Indigenous knowledge was the guiding instrument to undertake conservation agriculture. The Matengo pits in Ruvuma, closed pasture (locally ngitiri) in Shinyanga region to mention few are some of the conservation agriculture practices done in Tanzania to increase crop yields, control erosion, to mention few. Conservation agriculture practices have contributed to increase crop yields, curb food insecurity and sequester atmospheric carbon dioxide into the soil. Despite of this meagre achievement; agricultural officers, politicians and other stakeholders emphasize the use of tractors and oxen plough to till the soil. They believe that agriculture without tillage is utopian. The desire to get more yield had driven some farmers to apply chemical fertilizer and other inputs to speed up crop production, however this chemical application has degraded the natural soil quality and increased the emission of greenhouse gases. The long-term chemical fertilization in various part of the country has degraded of soil. Ismani division in Tanzania is a good example of this severe degradation. The authors recommend the adoption of conservation agriculture practices in the farming systems taking into consideration spatial differentials in terms of biophysical and socioeconomic characteristics of the area. They suggest that Livestock keeping should be integrated with crop production to allow the efficiency of the practices. Animal manures and straw from crops (especially maize, rice, millet and sorghum) should be decomposed and used as organic matters in the farms to fertilize the soil. Planners, policy makers, agricultural experts and other agricultural stakeholders should consider conservation agriculture practices in Tanzanian agro-ecosystems for environmental conservation and sustainable agriculture.
Article extracted from a chapter “ Conservation Agriculture in Tanzania by Msafiri Mkonda and Xinhua He in © Springer International Publishing Switzerland 2017 309
E. Lichtfouse (ed.), Sustainable Agriculture Reviews, Sustainable Agriculture Reviews 22, DOI 10.1007/978-3-319-48006-0_10
The authors can be reached at
Department of Physical Sciences, Faculty of Science, Sokoine University of Agriculture,
3038, Morogoro, Tanzania
School of Plant Biology, University of Western Australia, 6009, Crawley, Australia