ABSTRACT

The responses of soil P availability and cotton growth to biochar addition under different P supply levels are not well documented. Thus, a pot experiment was conducted to investigate the effects of biochar addition on soil nutrient status, microbial characteristics related to P cycling and cotton growth with or without adequate P supply. Biochar was added to soil grown cotton at three rates of 0, 3 and 30 t ha⁻¹ under two P fertilizer levels of 0 and 150 kg P₂O₅ ha⁻¹, respectively. Results showed that biochar addition had significantly positive effects on soil P availability, phosphate solubilizing bacteria number, phosphatase activities (except acid phosphatase activity), cotton nutrients uptake and seedcotton yield, regardless of P fertilization level. The magnitude of soil available P content increase after biochar addition with P fertilizer was greater than without P fertilizer. And 3 t ha⁻¹ biochar was better than 30 t ha⁻¹ biochar for converting soil P into available P. Under a given P fertilizer level, biochar addition had fertilizer-like diminishing effect on seedcotton yield. Conclusively, the co-application of P fertilizer and the appropriate amount of biochar could be beneficial for soil P availability in cotton production.

摘要

在不同的磷供应水平下，土壤磷有效性和棉花生长对生物炭添加的响应没有得到很好的记录。因此，进行了一项盆栽试验，以研究添加生物炭对土壤养分状况、与磷循环相关的微生物特性以及在有或没有足够磷供应的情况下棉花生长的影响。_{在 0 和 150 kg P 2} O ₅ ha ^-1两种磷肥水平下，以 0、3和 30 t ha ^-1三种比例将生物炭添加到土壤种植的棉花中， 分别。结果表明，无论施磷水平如何，添加生物炭对土壤磷有效性、溶磷菌数量、磷酸酶活性（酸性磷酸酶活性除外）、棉花养分吸收和籽棉产量均有显着正向影响。添加磷肥生物炭后土壤速效磷含量增加的幅度大于不添加磷肥的生物炭。3 t ha ^-1生物炭比30 t ha ^-1生物炭更能将土壤磷转化为有效磷。在给定的磷肥水平下，生物炭的添加对籽棉产量具有类似肥料的递减效应。综上所述，磷肥与适量生物炭配合施用有利于棉花生产中土壤磷的有效性。