覆盖和粮草间作对作物氮素吸收利用和土壤硝态氮累积的影响

摘要

In order to maintain the sustainable development of agriculture and to reduce the inputs of nitro-gen fertilizer and common plastic film in agricultural production,a experitment with completely randomized split-plot design was conducted from March to October in 2013 at Gansu Agricultural University Experiment Station,Huangyang Town,Wuwei City,Gansu Province.Effects of planting patterns (maize monoculture, maize//hairy vetch intercropping and maize//common vetch intercropping)and mulching methods (common plastic film mulching,biodegradable film mulching,straw mulching and no-mulching)on crop nitrogen uptake and nitrate nitrogen (NO-3 -N)accumulation in soil were studied in the experiment.The results showed that mulching and intercropping promoted the nitrogen uptake by crops.At maize harvesting stage,compared with no-mulching,the increases of nitrogen uptake by maize under common plastic film mulching,biodegradable film mulching and straw mulching were 21.46%,1 1.22% and 34.63%,respectively.Compared with maize monocul-ture,the increases of nitrogen uptake by maize with maize//hairy vetch intercropping and maize//common vetch intercropping were 6.94% and 6.26%,respectively.At maize harvesting stage,compared with common plastic film mulching,biodegradable film mulching and no-mulching,the increases of nitrogen uptake by forages under straw mulching.were 46.75%,72.31% and 21.76%,respectively,Compared with intercropping common vetch, the nitrogen uptake of intercropping hairy vetch significantly increased by 25.26%.At maize harvesting stage, the soil NO-3 -N accumulation from 0 to 140 cm in the maize belts and forage belts were below than that at fora-ges harvesting stage.Whether at forages or maize harvesting stage,soil NO-3 -N accumulation in the maize belts and forage belts of maize monoculture were below than that in intercropping maize.At maize harvesting stage, compared with no-mulching,the increases of soil NO-3 -N accumulation in the maize belts under common plastic film mulching and biodegradable film mulching were 32.87% and 27.82%,respectively.Compared with biode-gradable film mulching,straw mulching and no-mulching,the increases of soil NO-3 -N accumulation in the for-age belts under common plastic film mulching were 9.17%,6.07% and 27.82%,respectively.%为了减少普通地膜和氮肥的投入,实现该地区农业生态良性循环和土壤的可持续利用,在甘肃武威试验站采用完全随机裂区设计,研究了不同种植模式(玉米单作、玉米//毛苕子和玉米//箭筈豌豆)和覆盖方式(普通地膜覆盖、生物可降解地膜覆盖、秸秆覆盖和无覆盖)对玉米和绿肥作物氮素吸收以及土壤硝态氮累积的影响。结果表明：覆盖和间作对作物的氮素吸收利用具有显著促进作用。玉米收获期,与无覆盖相比,普通地膜覆盖、生物可降解地膜覆盖和秸秆覆盖的玉米植株吸氮量分别增加21.46%,11.22%和34.63%,与玉米单作相比,玉米//毛苕子和玉米//箭筈豌豆的玉米吸氮量分别增加6.94%和6.26%。玉米收获期,秸秆覆盖的牧草植株吸氮量较普通地膜覆盖、生物可降解地膜覆盖和无覆盖分别增加46.75%,72.31%和21.76%,间作毛苕子的吸氮量较间作箭筈豌豆增加25.26%。玉米收获期,各处理玉米带、牧草(裸露)带0~140 cm 土壤硝态氮累积量均低于牧草收获期,无论牧草收获期还是玉米收获期,单作玉米的玉米带、裸露带土壤硝态氮累积量均低于间作玉米。玉米收获期,普通地膜覆盖和生物可降解地膜覆盖的玉米带0 ~140 cm 土壤硝态氮累积量较无覆盖分别显著增加32.87%和27.82%,普通地膜覆盖的牧草(裸露)带0~140 cm 土壤硝态氮累积量较生物可降解地膜覆盖、秸秆覆盖和无覆盖分别增加9.17%、6.07%和35.45%。