针对长期不合理高化肥投入量导致城郊区菜地土壤环境恶化的现状,为探讨氮肥减施对城郊区菜地土壤氮磷累积及蔬菜产量品质的影响,应用田间小区试验,研究了长沙市郊2种不同菜地土壤中,氮肥减施20%与缓释尿素,脲酶抑制剂/硝化抑制剂,土壤调理剂配合施用的环境和农学效应。结果表明:与常规施肥处理相比,采用缓释尿素减施20%化学氮肥(80%N(CRU))有效降低了菜地土壤Olsen-P和NO3--N的含量,减少了其面源污染风险,但该处理蔬菜可食部分容易累积硝酸盐,也增加了食用风险;通过添加脲酶抑制剂/硝化抑制剂减施20%化学氮肥(80%N+QD),生育中期土壤NH4+-N含量和蔬菜鲜样产量分别增加了69.2%,262.0%(p〈0.05)和2.5%,12.1%(p〈0.05),对土壤Olsen-P、NO3--N以及可食部分硝酸盐含量影响不显著;减施20%化学氮肥配以添加土壤调理剂(80%N+SC)在2种种植年限的菜地中效果欠稳定。兼顾经济、食用风险、生态环境等效益,建议在高肥力菜地施肥实践中,氮肥减施与脲酶抑制剂/硝化抑制剂配合施用。
In order to explore soil nitrogen and phosphorus accumulation,vegetable yeild and quality influenced by reduction and optimization of nitrogen fertilizer application in peri-urban,two field experiments were carried out in vegetable fields to investigate the environmental and agronomic effects.N was reduced by 20% with following optimized fertilization strategies,referred to as slow-release urea(80%N(CRU));urease/nitrification inhibitors(80%N+QD);soil conditioner(80%N+SC),respectively.The results showed that,compared with conventional fertilization strategy(CF),the strategy of 80%N(CRU) reduced soil NO-3-N and Olsen-P effectively,while increased the NO-3 in edible parts of vegetable.The strategy of(80%N+QD) had no significance effects on Olsen-P,NO-3-N in soil and NO-3 in edible parts,but increased soil NH+4-N in growth medium and the fresh production in harvest obviously,69.2%,262.0%(p0.05)and 2.5%,12.1%(p0.05) respectively.However,the strategy of(80%N+SC) was proved to be no significant in the two test fields.Considering the production,health safety and ecological benefits,it was suggested that the use of urease inhibitors/nitrification inhibitors with reduced nitrogen fertilizer should be adopted in the fertile vegetable cultivation soils.