Effect of Mixed Biochar-Compost Based on Dead Biomasses of Prosopis juliflora and Eichhornia crassipes on the Productivity and Biodiversity of Arid Sandy Soils in the Sahelian Zone

The Biochar-Compost mixture based on the dead biomass of Prosopis juliflora and Eichhornia crassipes can be used as an input in agricultural production. The objective of this study is to determine the capacity of the Biochar-Compost mixture based on the dead biomass of Prosopis juliflora and Eichhornia crassipes on the restoration and productivity of degraded arid soils in the Cameroonian Sahel. A randomized complete block design (RCBD) was used to test the effect of the Biochar-Compost mixture on a sandy-clay soil (95%-05%) with and without Compost_Biochar based on Prosopis juliflora_Eichhornia crassipes. The Berkley rapid composting method was used to produce the compost while the carbonization method developed by SAHEL NATURE CONSULTING FOR COMMUNITIES was used to produce the biochar. In this experiment, the Biochar-Compost mixture based on the dead biomass of Prosopis juliflora and Eichhornia crassipes was applied to the cultures of Zea mays and Solanum lycopersicum L. above at 5, 10, 15, and 20 t/ha with and without Compost_Biochar based on Prosopis juliflora_Eichhornia crassipes. The results showed a significant increase in seed germination percentage as we applied more of 15 t/ha of Compost_Biochar 2 (47.36-52.63)% based on Prosopis juliflora_Eichhornia crassipes to agricultural land abandoned due to its degradation due to aridity and silting. The study also showed an increase in crop biomass using Biochar (100%) based on Prosopis juliflora_Eichhornia crassipes alone and/or in combination with Compost based on Prosopis juliflora_Eichhornia crassipes on sandy clay soil T03 (95% -05%). The application of this Compost_Biochar based on Prosopis juliflora_Eichhornia crassipes on sandy clay soil T03 (95%-05%) also increases the growth of shoots and roots of crops, then improves crop yield by improving the physicochemical properties and biological soils, which is probably the reason why Compost_Biochar based on Prosopis juliflora_Eichhornia crassipes on sandy clay soil T03 (95%-05%) could contribute to plant productivity. In view of the percentage of leaching obtained due to runoff water, we conclude that, even in conditions of high precipitation (floods or irregular rainfall), leached soils from highlands for example could be sustainably improved by an amendment to Compost_Biochar based on Prosopis juliflora_Eichhornia crassipes. Based on the results of the study, it can be recommended that the application of Compost_Biochar based on Prosopis juliflora_Eichhornia crassipes on a sandy clay soil T03 (95%-05%) with a view to restoring degraded agricultural soil and improve seed germination potential, crop growth performance and dry matter yield without chemical fertilizer.

以牧豆树（Prosopis juliflora）和凤眼蓝（Eichhornia crassipes）枯死生物质制备的生物炭-堆肥混合物，可作为农业生产的投入物料。本研究旨在明确该牧豆树-凤眼蓝基生物炭-堆肥混合物对喀麦隆萨赫勒地区退化干旱土壤的修复潜力与生产力提升效能。实验采用完全随机区组设计（Randomized Complete Block Design, RCBD），在砂质黏土（95%砂-5%黏土）土壤上设置添加与不添加牧豆树-凤眼蓝基堆肥-生物炭的两组处理。堆肥采用伯克利快速堆肥法制备，生物炭则由SAHEL NATURE CONSULTING FOR COMMUNITIES研发的炭化工艺制备。本实验中，研究人员将该牧豆树-凤眼蓝基生物炭-堆肥混合物以5、10、15、20 t/ha的施用量，施加于玉米（Zea mays）与栽培番茄（Solanum lycopersicum L.）的栽培体系中，同时设置未添加该改良剂的对照处理。结果显示，向因干旱与淤积退化而撂荒的农田施加15 t/ha以上的牧豆树-凤眼蓝基堆肥-生物炭2号（47.36%~52.63%）时，种子发芽率显著提升。研究还发现，在T03号砂质黏土（95%砂-5%黏土）土壤中，单独施用100%用量的牧豆树-凤眼蓝基生物炭，或其与牧豆树-凤眼蓝基堆肥配施，均可提升作物生物量。向T03号砂质黏土土壤施加该牧豆树-凤眼蓝基堆肥-生物炭，还可促进作物地上部与根系生长，并通过改善土壤理化性质与土壤生物学特性提升作物产量，这也是该改良剂助力植物生产力提升的潜在机制。基于径流引发的淋溶占比数据，本研究得出结论：即使在强降水（洪涝或降雨不均）条件下，高地淋溶土壤等退化农田也可通过施加牧豆树-凤眼蓝基堆肥-生物炭实现可持续改良。基于本研究结果，建议在T03号砂质黏土（95%砂-5%黏土）土壤中施加该牧豆树-凤眼蓝基堆肥-生物炭，以修复退化农田，提升种子发芽潜力、作物生长性能与干物质产量，且无需额外施用化学肥料。