BackgroundCassava is a heavy feeder crop that can cause serious depletion to soil nutrient stocks. This research aimed to explore soil fertility status and nutrient supply capacity at different growth stages of cassava fields under combined application of organic manure and NPK fertilizers in two agroecologies of Zambia. Topsoil (0–20 cm) samples were collected from cassava fields treated with factorial combination of four levels of chicken manure (0, 1.4, 2.8, and 4.2 ton ha−1) and four levels of NPK (control, 50N-11P-41.5K, 100N-22P-83K, and 150N-33P-124.5P). The soils were sampled under the cassava canopy to determine soil pH, available phosphorus (AP), total nitrogen (TN), organic carbon (OC), cation exchange capacity (CEC), exchangeable bases and micronutrients (Fe, Cu, Mn, and Zn). The samples were collected before planting andafter establishment at 4, 8, and 12 months after planting (MAP).ResultsManure application significantly (p < 0.05) increased soil pH, while the application of mineral fertilizer reduced soil pH at all the plant growth stages. Similarly, manure application and their interaction with mineral fertilizer increased OC and TN levels, especially at harvest. By contrast, OC and TN decreased with the application of mineral fertilizer. AP levels increased following the application of both fertilizers. In addition, manure application significantly increased soil Zn content from 0.69 mg kg−1 in the control to 3.54 mg kg−1 for the highest level of manure at harvest. The interaction between manure and NPK significantly affected Fe and Mn content in the soil.ConclusionThe results revealed that sole chicken manure application or its combination with mineral fertilizer improves soil nutrient status of cassava fields in Zambian condition.

中文翻译：

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赞比亚粪肥与氮磷钾肥复合处理木薯田的土壤肥力状况

背景木薯是一种重度饲养作物，可导致土壤养分储备严重枯竭。本研究旨在探讨赞比亚两种农业生态系统中有机肥与氮磷钾复合肥配施下木薯田不同生育阶段的土壤肥力状况和养分供应能力。从用四种水平的鸡粪（0、1.4、2.8 和 4.2 吨 ha-1）和四种水平的 NPK（对照，50N-11P-41.5）的因子组合处理的木薯田收集表土（0-20 厘米）样品K、100N-22P-83K 和 150N-33P-124.5P）。在木薯冠层下对土壤进行取样，以确定土壤 pH 值、有效磷 (AP)、总氮 (TN)、有机碳 (OC)、阳离子交换能力 (CEC)、可交换碱和微量营养素 (Fe、Cu、Mn 和锌）。在种植前和种植后 4、8 和 12 个月（MAP）采集样品。结果施肥显着（p < 0.05）增加了土壤 pH 值，而施用矿物肥料降低了所有植物生长阶段的土壤 pH 值。同样，粪肥施用及其与矿物肥料的相互作用增加了 OC 和 TN 水平，尤其是在收获时。相比之下，OC和TN随着矿物肥料的施用而减少。施用两种肥料后，AP 水平增加。此外，施肥显着增加了土壤锌含量，从对照的 0.69 mg kg-1 增加到收获时最高水平的 3.54 mg kg-1。粪便与 NPK 之间的相互作用显着影响土壤中的 Fe 和 Mn 含量。