改性果木生物炭对石灰性土壤磷有效性及小麦生长的影响OA

To investigate the regulatory effects of fruit-wood biochar modified by different chemical methods on phosphorus availabili-ty in calcareous soil and wheat growth,and to optimize the application strategy of biochar in phosphorus management,the effects of fruit-wood biochar modified by KH2PO4,citric acid,and HCl on the available phosphorus content in calcareous soil,the dry weight of wheat,and the phosphorus uptake in wheat shoots were systematically evaluated through an incubation experiment and a pot experi-ment.The results showed that among the three modified treatments,there was no significant difference in the available phosphorus con-tent between the rinsed and unrinsed biochar,so the unrinsed biochar was uniformly used in the subsequent experiments.The modifi-cation with KH2PO4 significantly increased the available phosphorus content of the biochar.After application to the soil,it could re-lease phosphorus,causing the soil available phosphorus content to reach a peak at 14 days and maintain a relatively high level for a long period.At an application rate of 2.0％,a second release peak appeared at 40 days,demonstrating a good slow-release property.The biochar modified by KH2PO4 showed the best effect at an application rate of 1.0％,which not only significantly increased the dry weight of wheat but also significantly enhanced the phosphorus uptake in wheat shoots.After the application of biochar modified by cit-ric acid or HCl to the soil,there was no obvious change in the soil available phosphorus content.The biochar modified by KH2PO4 was more suitable as a slow-release phosphorus carrier for the amelioration of calcareous soil.