关键词: 生物炭, 土壤, 氮磷流失, 油菜

Abstract: It is a key issue in biochar applying technology to clear and definite the effects of biochar in reducing nitrogen and phosphorus loss of soil and crop  yield. Using tube experiment, this paper added different portions biochar (0.5%, 1.0%, 1.5%) to 20 cm soil layer, simulated rainfall and collected the liquid inside the tube, then tested and analyzed nitrogen and phosphorus contents. By this way, the paper studied the effects of adding different proportions of biochar on soil nitrogen and phosphorus leaching and rapeseed growth. The results showed that: ① Compared with no biochar treatment, 1.5% biochar treatment significantly reduced TN leaching loss, TN leaching concentration ratio, NO-3-N leaching loss, NO-3-N leaching concentration ratio, TP leaching loss and TP leaching concentration ratio; there was no significant difference in the leaching loss of NH+4-N and PO2-4-P among the treatments. ② During rapeseed growing period, the leaching loss of TN and NO-3-N decreased with the increase of biochar application, taking NO-3-N leaching loss as the major part. Affected by fertilization and utilization during crop growth, the rules of leaching loss of NH+4-N, TP and PO2-4-P were not obvious. ③ Biochar application increased rapeseed yield, mainly reflected in the increase in effective branching number, efficient pod number per plant and seed number per fruit.

Key words: biochar, soil, nitrogen and phosphorus loss, rapeseed