S13 - Session P1 - Ways of improved soil management through valorisation of crop residues in the Senegal River Valley

Authors: Daniel Kalnin *, Bettina Fähnrich

This study explores the feasibility of crop residue valorisation to improve soil quality for market gardening in Senegal. Horticultural farms in the Senegal River Valley mainly produce sweet corn, butternut and carrots. Crop residues of these represent a huge quantity that are currently left on the fields for the unaccounted use of indigene population. Market gardening in the sandy soil of Senegal often leads to soil depletion. Control of root and stem nematodes in corn is the most challenging plant protective task in the area. Transformed or direct crop residues incorporated into the soil can provide organic matter and nutrients to avoid loss of soil fertility. Furthermore, bioactive plant compounds can provide desired phytosanitary effects against soil-borne pathogens and pests. Three paths of valorisation of crop residues seem feasible: i) Transformation by use as animal feed can lead to a return of animal residues to the field after composting. ii) Composting of the biomass itself can create valuable fertilisers. iii) Leftovers of catch and cover crops in crop rotation may entail phytosanitary effects and avoid nutrient loss.Crop residues can be preserved as animal feed in a wet way (e.g. corn silage) or in a dry way (e.g. residues of peanut plants or green beans). Enhanced incorporation of indigenous, bioactive metabolites bearing plants (e.g. medicinal or aromatic crops) as catch crops can improve productivity of main crops and provide additional income. Our study wants to explore the status quo and address the economic feasibility as well as the marketing aspects of the described approaches on a single farm level for Senegalese conditions.