Carbon and nutrient dynamics in biochar co-composts and their effects on C balances, soil properties and crop yields in Ghana

加纳生物炭复合堆肥中的碳和养分动态及其对碳平衡、土壤性质和作物产量的影响

• 批准号: 410207775
• 负责人: Professor Dr. Bernd Marschner
• 金额: --
• 依托单位: Geographisches Institut
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/410207775?language=en
• 关键词: Carbon; nutrient; dynamics; biochar; co

Soils in Sub-Saharan Africa are naturally low in SOC and nutrients and are often further degraded by unsustainable land management practices, resulting in low crop yields. Maintaining or better, increasing soil organic carbon plays a crucial role in enhancing soil fertility for sustainable agricultural production. However, the availability of materials for increasing SOC levels is limited in Africa, and their use is often accompanied by rapid mineralization and high leaching losses. Composting organic household and market wastes is an emerging technology in some areas but high carbon and nitrogen losses during production and after field application reduce its efficiency. Based on other studies and some own preliminary results, the addition of biochar appears to be a promising option for increasing compost stability and thus its suitability for improving soil fertility. However, the underlying mechanisms for C and nutrient retention during co-composting and soil incorporation are still poorly understood. Therefore, the general objectives of the project are i) to investigate the effects of biochar co-composting on C and N dynamics during composting and ii) to study and document the mechanisms underlying the effect of composted biochar application on soil quality indicators, greenhouse gas emissions and crop yield in typical soils used for agricultural production in Ghana.The project will be conducted as a collaborative study with Dr. Kwame Frimpong from the University of Cape Coast (Ghana) involving compost production, greenhouse experiments and field trials in Ghana and laboratory experiments and comprehensive physical, chemical and biological compost and soil characterization in Bochum. Compost will be produced from a mixture of organic household wastes, rice straw and poultry manure, amended with different rates of two different biochars (from rice husks and corn cobs). During compost production and after its application to the three field sites in Ghana, the emissions of greenhouse gases (CO2, N2O, NH3 and CH4) will be monitored. The associated changes in biochar and biochar-compost properties will be analyzed in samples exposed in mesh bags in the compost and in the field. Source-differentiated C balances will be calculated from 13C data and C-stabilizing mechanisms will be determined from sequential extractions and from density and aggregate fractions. Together with the yield data from the greenhouse and field experiments, the results of this study will show if the production and application of biochar co-composts can enhance C sequestration, soil fertility and crop yield in these tropical soils.

撒哈拉以南非洲地区的土壤自然较低，养分较低，通常会因不可持续的土地管理实践而进一步降低，导致农作物产量低。维持或更好的是，增加土壤有机碳在增强土壤生育能力的可持续农业生产方面起着至关重要的作用。但是，非洲的材料可用于提高SOC水平的材料受到限制，并且它们的使用通常伴随着快速的矿化和高浸出损失。在某些地区堆肥有机家庭和市场浪费是一种新兴技术，但是在生产期间和现场应用程序后，高碳和氮损失降低了效率。基于其他研究和一些自己的初步结果，加入生物炭似乎是提高堆肥稳定性的有前途的选择，从而适合改善土壤生育能力。然而，在共同体和土壤掺入过程中C和养分保留的基本机制仍然很少了解。因此，该项目的一般目标是i）研究堆肥过程中生物炭共同组合对C和N动态的影响。 （加纳）涉及加纳和实验室实验中的堆肥生产，温室实验和现场试验，以及Bochum中综合的物理，化学和生物堆肥和土壤表征。堆肥将是由有机家庭废物，稻草和家禽粪的混合物产生的，该肥料以不同的生物壳（来自稻壳和玉米棒）进行了修改。在堆肥生产中以及在加纳的三个田间现场应用后，将监测温室气体（CO2，N2O，NH3和CH4）的排放。将在堆肥和现场的网格袋中暴露的样品中分析生物炭和生物炭塑料的相关变化。源划分的C平衡将根据13C数据计算，C稳定机制将由顺序提取以及密度和聚集分数确定。连同温室和田间实验的产量数据，这项研究的结果将表明生物炭共同塑料的生产和应用是否可以增强这些热带土壤中的C隔离，土壤生育能力和作物产量。