Effects of Compost from Jatropha curcas on Soil Biochemistry and Microbial Community Diversity

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Résumé

Agriculturally underutilized bioresources such as Jatropha curcas, rich in nitrogen, phosphorus, and potassium, may represent alternative low-cost fertilizers. The aim of the study was to evaluate the effect of different composts based on Jatropha curcas by-products on the biochemical and microbiological properties of soil. Composts based on Jatropha by-products were evaluated for their effect on soil biology and enzyme activity. The DGGE method was used to assess the diversity of microbial communities, and analysis of the results showed that the structure of the total soil bacterial community is influenced by the activators used for composting. The microbial biomass of the treatments varied significantly between 20 and 40 μgC.g−1 soil. The results show that the evolution of carbon mineralization is identical for all treatments. The rates of C-CO2 release did not differ statistically for either treatment on days J0, J1, or J2. Between days J3 and J7, the analysis of variance shows statistically greater differences in cumulative C-CO2 release for all the treated soils and the control soil. The activities of glycosyl hydrolase, i.e., β-glucosidase [EC 3.2. 1.21] varied from 17.2 ± 0.6 μg.p-NP.g(soil)−1.h−1 to 32.5 ± 7.8 μg.p-NP.g(soil)−1.h−1. The same applies to acid phosphatase activity, with values ranging from 57.7 ± 1.2 to 117.6 ± 2.2 μg.p-NP.g(soil)−1.h−1. The use of organic matter was efficient for microbial biomass. An agricultural intensification strategy could use biological control in the management of agricultural ecosystems by using bio-composts.

Mots-clés

Jatropha curcas L ,composts , biomass ,soil enzyme ,microbial community ,Burkina Faso