有机无机氮肥配施对典型菜地土壤微生物和酶活性的影响

为了比较不同种类有机无机氮(N)肥配施后典型菜地土壤微生物和酶活性的差异,揭示施用有机物料后微生物在调节土壤肥力中的作用,以猪粪、沼渣沼液和猪粪堆肥为供试材料,采用田间小区试验,设置不施肥(CK)、不施N肥(PK)、纯施化肥(NPK)、有机无机肥配施1(20%猪粪N+80%化肥N,NPKM1)、有机无机肥配施2(20%沼渣沼液N+80%化肥N,NPKM2)和有机无机肥配施3(20%猪粪堆肥N+80%化肥N,NPKM3)等6种施肥模式,连续3年(2011-2013年)研究不同有机无机N肥配施对典型菜地土壤微生物和酶活性的影响。结果表明:小白菜季和莴苣季生育期间土壤细菌数量呈上升趋势,土壤真菌、放线菌数量呈先升后降趋势,且栽培后季较前季高。与NPK处理相比,NPKM1、NPKM2、NPKM3处理土壤细菌数量提高2.27%~26.16%(小白菜季),15.06%~40.82%(莴苣季);真菌数量提高33.62%~47.10%(小白菜季),39.64%~52.27%(莴苣季);放线菌数量提高6.59%~38.21%(小白菜季),20.97%~29.66%(莴苣季)。有机无机N肥配施可以促进菜地土壤微生物大量繁殖。与NPK处理相比,NPKM1、NPKM2、NPKM3处理提高土壤脲酶、磷酸酶、过氧化氢酶、纤维素酶的活性。有机无机N肥配施可以促进菜地土壤酶活性的提高。各处理蔬菜产量分别为6.73~22.50 t/hm2(小白菜),21.54~47.79 t/hm2(莴苣),大小均表现为NPKM3NPKM1NPKM2NPKPKCK。相关分析表明,小白菜和莴苣产量与土壤微生物数量和酶活性之间均存在密切关系。总之,有机无机N肥配施可以有效提高土壤中微生物数量和酶活性,维持菜地较高的土壤肥力,有利于蔬菜种植的可持续和高效生产,以猪粪堆肥配施效果最佳。

Effects of Organic and Inorganic Nitrogen Fertilizer on Soil Microorganism and Enzyme Activity of Typical Vegetable Soil

Field experiments were conducted to study the effects of different organic and inorganic nitrogen (N) fertilizers on soil microorganism and enzyme activity of typical vegetable soil for pakchoi and lettuce across three years from 2011 to 2013,using pig manure,biogas manure and pig manure composting as materials,including no fertilizer (CK),no N fertilizer (PK),chemical fertilizer (NPK),organic and inorganic fertilizer 1 (20% pig manure N + 80% chemical fertilizer N,NPKM1),organic and inorganic fertilizer 2 (20% biogas manure N + 80% chemical fertilizer N,NPKM2)and organic and inorganic fertilizer 3 (20% pig manure composting N + 80% chemical fertilizer N,NPKM3).Results showed that soil bacteria number was on the rise,while soil fungi and actinomycetes number appeared to rise first and then fall later during vegetable growing season,and the microbial population in following season were higher than that of previous season.Compared with NPK treatment,NPKM1,NPKM2,NPKM3 treatments increased soil bacteria number by 2.27%-26.16% (Pakchoi),15.06%-40.82% (Lettuce);soil fungi number by 33.62%-47.10% (Pakchoi),39.64%-52.27% (Lettuce);soil actinomyces number by 6.59%-38.21% (Pakchoi),20.97%-29.66% (Lettuce).Organic and inorganic N fertilizer application could promote the reproducing of soil microorganisms in vegetable field.Compared with NPK treatment,NPKM1,NPKM2,NPKM3 treatments increased the activities of soil urease,phosphatase,catalase,and cellulase.Organic and inorganic N fertilizer application could promote the improvement of soil enzyme activity in vegetable field.The yield of each treatment were among 6.73-22.50 t/ha(Pakchoi) and 21.54-47.79 t/ha(Lettuce),and in the range of NPKM3>NPKM1>NPKM2>NPK>PK>CK.Correlation analysis showed that there was a close relationship between soil microorganism quantity,enzyme activity and yield for pakchoi and lettuce.In conclusion,organic and inorganic N application,especially pig manure composting,could effectively improve the soil microbial population and enzyme activities,and maintain high soil fertility plantation,facilitating the sustainable development and efficient production of vegetable.