郭蓉 霍志纯 林子欣 郭子韶 封力元 宋明萱 卢树昌

摘    要：针对集约化设施菜田夏季土壤磷素淋失严重的问题，本文研究了不同用量生物炭（0%，0.5%，2%，4%，8%）施用下填闲作物（甜高粱）对阻控和缓解磷淋失以及减少磷累积的规律。结果表明，2%生物炭处理更有利于甜高粱的生长，随着生物炭用量增加，饲用甜高粱生物量以及吸磷量均出现先增加后减小的特点。4%和8%处理显著增加了土壤有机碳含量，土壤溶解有机碳（DOC）和微生物量碳含量则是先增大后减小，峰值出现在2%处理，分别为639.32，237.42 mg·kg-1。种植甜高粱以后，土壤磷素水平显著降低，5%和2%处理全磷最多降低了1.9%，水溶性磷（0～30 cm）最多下降了50.8%，90～120 cm土层下降幅度最多达到了100%。因此，在本试验条件下得出，0.5%～2%生物炭施用水平为最佳用量范围，即添加12～48 t·hm-2最有利于阻控和缓解磷素的淋失。

关键词：生物炭;磷素吸收;碳磷形态;设施菜田;甜高粱

中图分类号：S514;S156       文献标识码：A      DOI 编码：10.3969/j.issn.1006-6500.2021.07.015

Abstract： In order to solve the serious problem of phosphorus leaching from soil of vegetable fields under intensive facilities in summer， this paper studied different amounts of biochar 0%， 0.5%，2%，4%，8%. The application of catch crops （sweet sorghum， Sorghum bicolor （L.） Menoch） has the effect of preventing and alleviating phosphorus leaching loss and reducing phosphorus accumulation.The results showed that 2% treatment was more conducive to the growth of sweet sorghum. As the amount of biochar increased， the biomass of forage sweet sorghum and phosphorus uptake both increased first and then decreased. The 4% and 8% treatments significantly increased the soil organic carbon content， while the soil dissolved organic carbon （DOC） and microbial biomass carbon content first increased and then decreased. The peaks appeared in the 2% treatment， which were 639.32 mg·kg-1 and 237.42 mg·kg-1 respectively. After planting sweet sorghum， the soil phosphorus level was significantly reduced. the total phosphorus of 0.5% and 2% treatment was reduced by 1.9% at most， the water-soluble phosphorus（0-30cm） was decreased by 50.8% at most， and the soil layer of 90-120cm was decreased by 100% at most. Therefore， under the experimental conditions， the 0.5%-2% biochar application level is the best dosage range， that is， the addition of 12-48 t·hm-2 is most conducive to controlling and alleviating phosphorus leaching.

Key words： biochar; phosphorus absorption; carbon and phosphorus forms; facility vegetable field;sweet sorghum

集約化设施菜田的磷肥施用过量导致土壤磷过度累积，通过地表径流、侵蚀、淋溶和菜田排水等进入地表和地下水，从而给周边环境造成巨大威胁[1]。大量未被植物吸收和利用的养分残留在土壤中，造成土壤酸化、面源污染等环境生态污染问题[2-3]，同时过量的磷不利于设施土壤的再种植，对作物生长和养分吸收产生不好的影响[4]。夏季气温与降水的影响对于磷素淋失的问题更为显著[5]，降低磷素环境污染的关键在于减少土壤中残留的磷素数量，这就需要提高磷素的资源利用率，同时控制菜田土壤磷素积累，降低其移动性[6]。……