生物炭对土壤氮磷流失和油菜产量的影响

明确生物炭对土壤氮磷流失和作物产量的影响是生物炭应用技术中的关键问题。采用测筒试验,在20 cm土壤中添加不同比例(0.5%、1.0%、1.5%)的生物炭,并模拟降雨淋溶后收集测筒淋溶液分析氮磷含量,研究生物炭对土壤氮磷淋溶流失和油菜产量的影响。结果表明:(1)与不施用生物炭处理相比,1.5%生物炭处理极显著降低了TN淋溶损失量、TN淋溶浓度比率、NO~-_3-N淋溶损失量、NO~-_3-N淋溶浓度比率、TP淋溶损失量和TP淋溶浓度比率;各处理间NH~(+2)_4-N和PO~-_4-P淋溶损失量差异不显著。(2)油菜生长期间,TN、NO~-_3-N的淋溶损失量随生物炭施用量增加而减少,且以NO~-_3-N的淋溶流失为主;受施肥和作物生长吸收利用的影响,NH~+_4-N、TP和PO~(2-)_4-P的淋溶流失规律不明显。(3)施用生物炭增加了油菜的产量,主要表现为油菜一次有效分支数、单株有效角果数和每果粒数的增加。

Influences of Adding Biochar on Loss of Nitrogen and Phosphorus and Yield of Rape in Soil

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.