炭基肥添加对蜜柚果园酸性土壤pH和交换性能的影响

为研究炭基肥添加对蜜柚果园酸性土壤pH和交换性能的影响,设不添加肥料空白(CK)、只添加尿素(N)、水稻秸秆炭基肥(rice straw biochar-based fertilizer,BR)和竹屑炭基肥(bamboo biochar-based fertilizer,BB)各4个用量梯度(2.5,5,10,20 g/kg)且配施尿素处理,开展60天室内培养试验。结果表明:随着培养进行,BR和BB处理土壤pH均先升高后降低,交换性酸和交换性盐基离子含量呈上升趋势。培养60天时,随着BR和BB施用量增加,对提升土壤pH、CEC及盐基饱和度,降低交换性酸、交换性铝等效果越明显,且BR效果优于BB。与N处理相比,BR和BB使土壤pH分别提升0.24~3.43和0.21~3.40个单位,交换性酸分别降低45.55%~97.25%和34.01%~96.70%,JP]交换性铝分别降低46.95%~99.75%和38.99%~99.00%,CEC分别提升7.02%~170.74%和6.52%~134.90%,盐基饱和度分别增加29.40%~51.61%和32.08%~53.90%。施用炭基肥可以提高蜜柚果园酸性土壤pH,减少土壤交换性酸,大幅度降低交换性铝含量,同时提升土壤CEC和盐基饱和度。蜜柚果园土壤酸化治理炭基肥适宜用量为2.5~5.0 g/kg,水稻秸秆炭基肥效果优于竹屑炭基肥。研究结果为蜜柚果园酸化土壤治理提供科学依据。

Effects of Biochar-based Fertilizer on pH and Exchange Capacity of Acidic Soil in Pomelo Orchard

This experiment explored the effects of the application of biochar-based fertilizer on the pH and exchange capacity of the acidic soil in pomelo orchard, and the laboratory culture experiments were conducted for 60 days. In the experiment, no fertilizer control (CK), single application of urea (N), rice straw biochar-based fertilizer (BR) and bamboo biochar-based fertilizer (BB) at four dosage gradients (2.5, 5, 10 and 20 g/kg) were set up, and urea was applied in all treatments. The results showed that with the development of culture experiment, the soil pH value of BR and BB increased first and then decreased, and the contents of exchangeable acid and base ions increased. After 60 days of culture, the improving effects of BR and BB on soil pH, exchangeable acid, exchangeable aluminum, CEC and base saturation became more obvious with the increasing of the dosage of BR and BB, and the effect of BR was better than that of BB. Compared with N treatment, in the BR and BB treatments, the soil pH increased by 0.24~3.43 and 0.21~3.40 units, the exchangeable acid decreased by 45.55%~97.25% and 34.01%~96.70%, the exchangeable aluminum decreased by 46.95%~99.75% and 38.99%~99.00%, the soil CEC increased by 7.02%~170.74% and 6.52%~134.90%, the base saturation increased by 29.40%~51.61% and 32.08%~53.90%, respectively. The application of biochar-based fertilizer could improve the pH of acidic soil, reduce exchangeable acid, greatly reduce exchangeable aluminum, and improve soil CEC and base saturation. Therefore, the optimum amount of biochar-based fertilizer for the acid soil of pomelo orchard was about 2.5~5.0 g/kg, and the effect of rice straw biochar-based fertilizer was better than bamboo biochar-based fertilizer. This experiment provided a scientific basis for the treatment of the acidified soil in pomelo orchard.