Integrated Soil Fertility and Plant Nutrient Management in Tropical Agro-Ecosystems: A Review

Abstract

The greatest challenge for tropical agriculture is land degradation and reduction in soil fertility for sustainable crop and livestock production. Associated problems include soil erosion, nutrient mining, competition for biomass for multiple uses, limited application of inorganic fertilizers, and limited capacity of farmers to recognize the decline in soil quality and its consequences on productivity. Integrated soil fertility management (ISFM) is an approach to improve crop yields, while preserving sustainable and long-term soil fertility through the combined judicious use of fertilizers, recycled organic resources, responsive crop varieties, and improved agronomic practices, which minimize nutrient losses and improve the nutrient-use efficiency of crops. Soil fertility and nutrient management studies in Ethiopia under on-station and on-farm conditions showed that the combined application of inorganic and organic fertilizers significantly increased crop yields compared to either alone in tropical agro-ecosystems. Yield benefits were more apparent when fertilizer application was accompanied by crop rotation, green manuring, or crop residue management. The combination of manure and NP fertilizer could increase wheat and faba bean grain yields by 50%-100%, whereas crop rotation with grain legumes could increase cereal grain yields by up to 200%. Although organic residues are key inputs for soil fertility management, about 85% of these residues is used for livestock feed and energy; thus, there is a need for increasing crop biomass. The main incentive for farmers to adopt ISFM practices is economic benefits. The success of ISFM also depends on research and development institutions to provide technical support, technology adoption, information dissemination, and creation of market incentives for farmers in tropical agro-ecosystems.

Soil Acidity and its Management Options in Ethiopia: A Review

“…The major mechanisms responsible for these improvements are thought to be the formation of organo-Al complexes that render the Al less toxic or direct neutralization of Al from the increase in pH caused by the organic matter. The possible alternative of using organic sources such as crop residues, manures, compost and biochar are substitutes for lime (Agegnehu and Amede, 2017). The authors demonstrated that organic sources raises pH and precipitate Al in direct proportion to its basic cation or ash alkalinity with a correction for the acidity produced during the oxidation of the N in the material.…”

Malting barley response to integrated organic and mineral nutrient sources in Nitisol

“…On the other hand, organic amendments are often not available on farm at the amounts required (Agegnehu and Amede 2017). The best alternative is integrating organic and mineral fertilizers for tackling soil fertility depletion and sustainably increasing crop yields (Agegnehu and Amede 2017;Getachew et al 2014b;Gete et al 2010).…”

Multi-level analysis of nutrient cycling within agro-sylvo-pastoral landscapes in West Africa using an agent-based model

“…Due to high demographic growth in West Africa, the demand for crop and livestock products is rapidly increasing, leading to the expansion of croplands onto rangelands, thereby constraining livestock mobility, see for instance in Burkina Faso (Vall et al, 2006). Consequently, the number of livestock and corresponding organic matter production are decreasing with a serious risk of soil fertility and crop productivity decline, as already pointed out by Pieri (1989), Lericollais (1999) and more recently by Agegnehu and Amede (2017). Two strategies to maintain livestock activities are commonly observed.…”