覆膜免耕对玉米间作豌豆农田土壤有机碳和氮的影响

Effects of No-tillage with Mulching of Plastic Film on Soil Organic Carbon and Total Nitrogen in Maize/Pea Intercropping System

借助2013年在河西绿洲灌区建立的不同耕作措施长期定位试验,通过探究耕作措施与种植模式对土壤有机碳和氮的变化特征,以期为构建试验区农田高效生产技术提供理论依据。试验设置耕作方式和种植模式两个因素,包括传统覆膜耕作(CT)和覆膜免耕(NT)2种耕作方式;单作玉米(M)、玉米间作豌豆(M/P)、单作豌豆(P)3种种植模式,共6个处理;通过分析不同种植模式下0~20 cm、20~40 cm土层土壤有机碳、全氮、硝态氮、铵态氮和C/N,明确覆膜免耕对禾豆间作农田土壤碳氮的影响。结果表明:与传统覆膜耕作相比,覆膜免耕显著增加0~20 cm土层土壤有机碳、全氮、硝态氮和铵态氮含量,2 a平均分别增加4.8%、5.3%、11.1%、17.8%,同时也增加20~40 cm土壤的有机碳、硝态氮和铵态氮含量,但对全氮含量影响不显著。在覆膜免耕措施下,玉米间作豌豆较单作玉米显著提高0~20 cm土层土壤有机碳、全氮、硝态氮和铵态氮含量,分别提高4.6%、7.0%、14.5%和21.6%,而20~40 cm土层中仅土壤全氮含量无显著差异。覆膜免耕较传统覆膜耕作降低0~20 cm土层的C/N,而种植模式之间土壤C/N表现为玉米间作豌豆小于单作玉米。相对于其他处理,覆膜免耕玉米间作豌豆体系能有效提高土壤有机碳、全氮及其组分。因此,在河西绿洲灌区玉米间作豌豆体系中,覆膜免耕玉米间作豌豆为该区域高效、可持续种植模式。

Based on the long-term positioning experiment of different tillage practices in Hexi oasis irrigation area since 2013,the effect of tillage practices and planting patterns on characteristics of soil organic carbon and nitrogen was explored,so as to provide a theoretical basis for the construction of high-efficiency farmland production technologies in this area.The two factors,including tillage practice and planting mode,were designed.Tillage practice included conventional tillage(CT)and no-tillage with mulching of plastic film(NT);and planting mode included sole maize(M),maize/pea intercropping(M/P),sole pea(P).The effect of no-tillage with mulching of plastic film on soil carbon and nitrogen in cereal/legume intercropping was determined by analysis of soil organic carbon,total nitrogen,nitrate nitrogen,ammonium nitrogen content and C/N at 0-20 cm and 20-40 cm soil layers under different planting modes.The results showed that compared with conventional tillage,no-tillage with mulching of plastic film increased the contents of soil organic carbon,total nitrogen,nitrate nitrogen and ammonium nitrogen in 0-20 cm soil layer by 4.8%,5.3%,11.1%and 17.8%respectively,and also increased the contents of soil organic carbon,nitrate nitrogen and ammonium nitrogen in 20-40 cm soil layers,but the effect on total nitrogen content was not significant.Under treatment of no-tillage with mulching of plastic film,compared with sole maize,maize/pea intercropping significantly increased the contents of soil organic carbon,total nitrogen,nitrate nitrogen and ammonium nitrogen in 0-20 cm soil layer by 4.6%,7.0%,14.5%and 21.6%respectively.Whereas,there was no significant difference of total nitrogen content in 20-40 cm soil layer compared with conventional tillage,No-tillage with mulching of plastic film reduced the soil C/N in 0-20 cm soil layer,and the soil C/N of maize/pea intercropping was lower than that of sole maize.Compared with other treatments,maize/pea intercropping system under the no-tillage with mulching of plastic film could significantly increase the soil organic carbon,total nitrogen and its components.Therefore,no-tillage with mulching of plastic film in maize/pea intercropping is an efficient and sustainable agronomic practice in Hexi oasis irrigation area.