摘要
为控制我国南方太湖地区设施蔬菜管理体系中夏季休闲期氮素淋失,减轻其对地下水污染的风险,本田间试验在太湖地区设施菜地夏季揭棚休闲期种植填闲作物(甜玉米),研究了不同施氮条件下甜玉米填闲处理对土壤硝态氮含量、电导率和pH变化的影响,并通过收集淋洗液的方法观测了甜玉米对土壤氮素淋洗及对下茬作物莴苣产量的影响。结果表明:与休闲相比,甜玉米填闲处理可使表层0～10 cm土壤硝态氮含量从251.4 mg kg-1下降至143.5 mg kg-1,0～50 cm土壤硝态氮残留减少4.19%～30.72%;种植甜玉米可显著降低土壤(0～10 cm)电导率,降幅达30%以上,但对pH影响不显著。从减少氮素淋洗角度看,甜玉米填闲处理虽不影响淋洗液体积,但可使农民习惯施氮量条件下淋洗液中总氮浓度从102.6 mg kg-1降低至53.7 mg kg-1。与休闲相比,甜玉米填闲处理可减少总氮淋洗30.4%,且对下茬莴苣产量无显著影响。在南方设施菜地夏季休闲期,利用种植填闲作物甜玉米的方式降低土壤氮素淋失风险是较直接有效的措施。
To explore ways to control nitrogen leaching loss from protected vegetable production systems during the summer fallow season and hence to mitigate the risk of N pollution of groundwater in the Taihu Lake region, a field experi- ment was conducted to evaluate effects of planting sweet corn as catch crop on NO~ -N content, soil electrical conductivity and pH in soils different in N application rate and further to observe its effects on nitrognn leaching using lysimeters and on yield of the following crop, lettuce. It was found that relative to fallow, planting sweet corn as catch crop reduced soil NO3-N concentration from 251.4 mg kg-1 to 143.5 mg kg-1 in the surface soil layer （0 - 10 cm） and by 4.2%-30.7% in the top soil （0 - 50 cm）. Besides, it reduced soil conductivity significantly, or by over 30% in the surface soil layer, but did not affect pH much. Although planting sweet corn didn＇t affect volume of leachate, it did reduce the total N conce- tration from 102.6 mg kg-1 to 53.7 mg kg-1 in leachate from plots receiving a high rate of N fertilizer under the conven- tional management practice. Compared with the fallow treatment, the sweet corn treatment reduced the total N leaching by 30.4% , which, however, did not have any effect, either positive or negative, on yield of the succeeding crop, lettuce. The findings indicate that in summer, the protected vegetable land in South China can be used to plant sweet corn as catch crop, instead of being left in fallow, which can be extrapolated as an efficient approach to reducing the risk of nitrogen leaching.
出处
《土壤学报》
CAS
CSCD
北大核心
2013年第2期331-339,共9页
Acta Pedologica Sinica
基金
公益性行业(农业)科研专项(201003014-1)
浙江农林大学科研发展基金(人才引进)(2010FR097)资助
关键词
太湖地区
设施菜地
填闲作物
氮淋洗
Taihu Lake region
Protected vegetable production
Catch crop
Nitrogen leaching loss
