The residual effects of biochar are yet to receive adequate research attention in Sub-Saharan Africa despite the assumption that the positive effect of biochar may last longer on degraded tropical soil. Hence a field experiment was conducted to assess the residual effects of biochar, farmyard compost and NPK fertilizer applications on a Ferralsol in central Uganda. The field used for the study was previously used to conduct experiments for two seasons to assess the contribution of corncob biochar to the chemical properties of this highly degraded tropical soil. The co-applied biochar with compost and NPK fertilizer significantly (p < 0.05) increased some soil chemical properties such as soil pH, available phosphorus, soil organic carbon, and potassium than the control. The co-applied biochar with compost also significantly (p < 0.05) increased the soil pH and effective cation exchange capacity compared to the solely applied compost and NPK fertilizer. Collard plant height, canopy, stem girth, number of leaves, leaf length, and total biomass were significantly (p < 0.05) higher in the biochar amended soil than the unamended soil. It was concluded that the addition of biochar with compost and NPK fertilizer had a significant residual effect on degraded tropical soils than solely applied NPK and compost.

中文翻译：

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玉米芯生物炭对乌干达中部热带退化土壤的残留影响

尽管假设生物炭对退化的热带土壤的积极影响可能会持续更长时间，但生物炭的残留效应在撒哈拉以南非洲尚未得到足够的研究关注。因此，进行了田间试验以评估生物炭、农家堆肥和 NPK 肥料对乌干达中部 Ferralsol 的残留影响。用于研究的田地以前用于进行两个季节的实验，以评估玉米芯生物炭对这种高度退化的热带土壤化学性质的贡献。与对照相比，生物炭与堆肥和 NPK 肥料的共同施用显着（p < 0.05）增加了一些土壤化学性质，如土壤 pH 值、有效磷、土壤有机碳和钾。与堆肥共同施用的生物炭也显着（p < 0。05) 与单独施用堆肥和 NPK 肥料相比，增加了土壤 pH 值和有效阳离子交换能力。生物炭改良土壤中的羽衣甘蓝植物高度、冠层、茎围、叶数、叶长和总生物量显着高于未改良土壤（p < 0.05）。结果表明，与单独施用 NPK 和堆肥相比，生物炭与堆肥和 NPK 肥料的添加对退化的热带土壤具有显着的残留影响。