Decision support tools for site-specific fertilizer recommendations and agricultural planning in selected countries in sub-Sahara Africa

Peer Revie

Science du sol et développement agricole au Rwanda : état de la question (synthèse bibliographique)

Soil science and agricultural development in Rwanda: state of the art. A review. Poor agricultural productivity remains a crucial problem in Rwanda in spite of numerous technological interventions, including aspects of soil management. The objective of this study was to draw lessons from the past with the view to better orient future interventions in soil fertility management. The literature review and iterative field observations were the sources of information. Findings from this study show that substantial progress has been made in the identification of different soil types and their spatial distribution. Factors related to low level of productivity have been identified and sustainable soil fertility management options have been developed at plot level. However, the widespread adoption of these technologies has been problematic. The main reason is the failure to tailor soil fertility management technologies to specific soil types. The study has demonstrated that the soil map of Rwanda (CPR for Carte Pédologique du Rwanda) – 1:50,000 – offers a remarkable potential to constitute a tool to solve this problem. In practice however, the CPR remains underutilized, mainly because of its inaccessibility to its potential users (e.g. policy makers, soil fertility experts, agronomists and extensionists). For its effective use, the following is recommended: Rwandan soil scientists need to increase policy makers' awareness about the usefulness of this soil map; agricultural research needs to adapt from the conventional model to a truly participatory and integrated approach; the CPR legend should be elucidated by providing information on the land units in which soils occur and by bridging Soil Taxonomy with the farmers' soil nomenclature; regional soil reference systems should be established that allow linking soil types with the fertility status of arable land and crop yields. This implies the need for training of Rwandan soil scientists in both Soil Taxonomy (the language of the CPR) and the farmers' soil nomenclature so that they can serve as interpreter for scientists from other disciplines and farmers. Rwandan soil scientists should be trained in the use of Geographic Information System (GIS) software to enable them to exploit the digitized version/soft copy of the CPR and to become familiar with the Rwandan biophysical environment

Can agroforestry enhance the resilience of agricultural commodity production systems?

Agricultural commodity production in a changing climate scenario is undergoing sustainability challenges due to degradation of soil fertility, water and biodiversity resources. In Africa, yields for important cereals (e.g., maize) have stagnated at 1 t ha−1 due to land degradation, low fertilizer use and water stress. Resource-conserving options such as agroforestry promote integrated management systems that relate livelihoods and ecosystem service functions to agricultural production. Low input practices including improved fallows using legumes in rotations or intercrops can restore soil nutrients, improve soil carbon and reduce reliance on fertilizer use by 50%. We review how agroforestry can sustain agricultural intensification in Africa by regulating ecosystem functions such as nutrient recycling, water use, species diversity and agrochemical pollution

A typology of farm households for the Umutara Province in Rwanda

Rwanda, Farm household, Farm typology, Technology adoption, Multivariate analysis,