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有机碳和养分含量天然较低，而且往往因不可持续的土地管理做法而进一步退化，导致作物产量低下。保持或更好地增加土壤有机碳在提高土壤肥力以促进可持续农业生产方面发挥着至关重要的作用。然而，在非洲，增加有机碳水平的材料的可用性是有限的，它们的使用往往伴随着快速矿化和高沥滤损失。有机家庭和市场废物堆肥在某些地区是一项新兴技术，但在生产过程中和实地应用后，碳和氮的大量损失降低了其效率。根据其他研究和一些自己的初步结果，添加生物炭似乎是一个很有前途的选择，增加堆肥稳定性，从而提高土壤肥力的适用性。然而，在共同堆肥和土壤掺入的C和养分保留的基本机制仍然知之甚少。因此，该项目的总体目标是：i）调查生物炭联合堆肥对堆肥过程中C和N动态的影响; ii）研究和记录堆肥生物炭应用对土壤质量指标影响的机制，温室气体排放和作物产量在加纳用于农业生产的典型土壤。该项目将作为一项合作研究与Kwame Frimpong博士进行该项目由海岸角大学（加纳）提供，涉及加纳的堆肥生产、温室实验和田间试验，以及波鸿的实验室实验和综合物理、化学和生物堆肥及土壤特性。堆肥将由有机家庭废物、稻草和家禽粪便的混合物制成，并以不同比例添加两种不同的生物炭（来自稻壳和玉米棒）。在堆肥生产过程中以及在加纳的三个实地应用之后，将监测温室气体（CO2、N2 O、NH3和CH 4）的排放。生物炭和生物炭堆肥特性的相关变化将在堆肥和田间的网袋中暴露的样品中进行分析。源分化的碳平衡将计算13 C数据和C稳定机制将确定从连续提取和密度和聚集分数。结合温室和田间试验的产量数据，本研究的结果将表明，生物炭共堆肥的生产和应用是否可以提高这些热带土壤的碳固存，土壤肥力和作物产量。