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Coffee is a crop that exports significant amounts of minerals from the soil, particularly through crop and pruning products. Maintaining sustainable productivity requires good knowledge and rational management of factors related to soil fertility and plant nutritional status, which would limit production. The objective of this study was to diagnose the mineral requirements of coffee plants in different production regions in order to recommend nutrient quantities adapted to the characteristics of each soil type for sustainable coffee production. Chemical analysis of 156 soil samples representative of the soil units of the coffee growing areas using a soil diagnostic model specific to coffee fertilization was used to determine the nutrient requirements of each soil unit studied. The results generally indicate that soil fertility levels were below the reference threshold values. Nutrient inputs are essential for all soils under coffee in large production areas. Nitrogen inputs are required in all soil units studied. The majority of the soils also showed a very pronounced potassium and calcium deficiency, while the phosphorus deficiency was not very pronounced. Magnesium, although generally in sufficient quantity in soils, has been readjusted to respect the balance in exchangeable bases. The amounts of nutrients to be supplied varied from one soil unit to another. Soils with low organic matter content showed relatively high requirements. Recommendations for appropriate soil fertility management per soil unit were presented in this work.

Coffee production in Côte d'Ivoire has been declining sharply for more than twenty years due to degradation in soil fertility status. The objective of this study was to map the mineral requirements of coffee trees in different production regions and to recommend immediate and long-term intervention strategies for soil management. In this study, the diagnosis of the chemical needs of 156 soil samples from major coffee production areas was used. We used a soil diagnostic model specific to coffee fertilization combined with geographic information systems (GIS). The combination of fertilizer formulas from the coffee soil diagnostic model, recent climatic data and soil units of the coffee growing areas allowed the elaboration of a thematic map showing a total of five basic formulas (N-P2O5-K2O-CaO-MgO) adapted to the real nutritional needs of coffee trees according to their agropedoclimatic environments. Two of these formulas cover 90% of the area studied. This study will enable appropriate soil management for the sustainable productivity of coffee trees in Côte d'Ivoire.

BACKGROUND: Phytophthora blight induced by Phytophthora capsici is responsible for serious yield loss in vegetable production in the United States and other countries. This study was conducted to evaluate the efficacy of Brassica cover crops used as soil amendments for managing Phytophthora blight of squash. RESULTS: In greenhouse studies, disease incidence on squash plants was significantly reduced by soil amendment with mustard shoots or roots used at 1 and 2.5% (plant tissue/soil, w/w). The shoots of canola used at 1 or 2.5% also suppressed disease, while the roots of canola or other crops did not reduce disease significantly. In field studies, soil amendments with mustard and canola provided the greatest disease reduction and increased squash yield significantly compared with the non-treated control. Mustard and canola did not appear to be susceptible to P. capsici. CONCLUSION: The results indicated that some Brassica crops, particularly mustard and canola, had the potential to significantly reduce Phytophthora blight on squash when used as soil amendments. As P. capsici has a remarkable ability to develop resistance to chemical fungicides, use of effective Brassica cover crops could be a biorational alternative to fungicides and a valuable component in developing integrated disease management programs. Copyright © 2011 Society of Chemical Industry