This study verified the inter-related effect of ‘market distance’, defined as walking time, ‘farm typology’, defined as resource endowment, and ‘site’, defined as geographic location with contrasting agro-ecologies, as well as farmers’ indigenous knowledge on soil fertility variability in smallholder farming systems in two distinct regions (Bushumba, Mushinga) of South-Kivu, DR Congo. A total of 384 soil samples were selected from representative farmers’ fields and analysed for soil pH, soil organic carbon (SOC) content and quality, as well as nutrient contents, using midDRIFTS (mid-infrared diffuse reflectance Fourier transform spectroscopy) and wet chemistry analyses. MidDRIFTS was also used to calculate SOC stability indexes as SOC quality proxies. ‘Market distance’ and ‘farm typology’ were key determinants of soil fertility variability, both with contrasting trends in Bushumba and Mushinga. Decreasing soil fertility with increasing market distance was noted across all farm typologies. ‘Farm typology’ was related to exchangeable calcium and magnesium, while ‘site’ resulted in a difference of plant available phosphorus. SOC quality indexes were related to ‘site’, interacting with ‘market distance’. A ‘market distance’ effect became obvious in the medium wealthy and poor farms of Mushinga, where a lower SOC quality in remote fields plots was noted with increasing market distance. In agreement with farmers’ indigenous knowledge, soil fertility levels were higher in deep than shallow soils, which were reflected in higher nutrient stocks in deep soils receiving organic amendments. Our results inferred that soil fertility variability across smallholder farms must consider various inter-related determinants as basis for site-specific fertility management interventions.

中文翻译：

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市场准入和资源end赋决定了刚果民主共和国南基伍省小农耕作制度的土壤肥力状况

这项研究验证了“市场距离”（被定义为步行时间），“农场类型”（被定义为资源end赋）和“站点”（被定义为具有不同农业生态特征的地理位置）以及农民的土著居民之间的相互影响。刚果民主共和国南基伍两个不同地区（布什穆巴，穆西加）的小农耕作系统中土壤肥力变异性的知识。使用MidDRIFTS（中红外漫反射傅里叶变换光谱法）和湿化学法，从代表性的农民田地中选择了384个土壤样品，分析了土壤的pH值，土壤有机碳（SOC）的含量和质量以及养分含量。分析。MidDRIFTS还用于计算SOC稳定性指标作为SOC质量代理。“市场距离”和“农场类型”是决定土壤肥力变异性的关键因素，布什姆巴（Bushumba）和穆申加（Mushinga）的发展趋势截然相反。在所有农场类型中，土壤肥力都随着市场距离的增加而降低。“农场类型学”与可交换的钙和镁有关，而“位点”导致植物可利用磷的差异。SOC质量指标与“站点”相关，与“市场距离”相关。“市场距离”效应在Mushinga中等富裕和贫穷的农场中变得很明显，在偏远田地中，随着市场距离的增加，SOC质量下降。与农民的本地知识相一致，深层土壤的肥力水平高于浅层土壤，这反映在接受有机改良剂的深层土壤中较高的养分储备中。