为探索适宜于青海高原春小麦的绿肥还田方式,本研究于2021-2022年进行田间试验,设置6个处理:常规施肥100%(F100)、70%(F70)、0%(F0),复种翻压绿肥配施化肥100%(F100+G)、70%(F70+G)、0%(F0+G),分析在不同处理下苗期、花期和收获期0~100 cm土层硝态氮和铵态氮的含量,以及春小麦整个生育期N2O的排放特征和小麦产量.结果表明:在复种翻压绿肥处理下春小麦穗数、穗粒数、千粒重和产量均显著提高(P<0.05),且F70+G处理的增产效果最佳,为6 025 kg/hm2;花期和成熟期硝态氮和铵态氮含量均表现为F70+G>F1 00+G>F70>F0+G>F1 00>F0.复种翻压绿肥配施化肥较单施化肥减少了农田N2O的排放,其中F70+G处理的N2O排放量较F70处理显著减少(P<0.05).同时,F70+G处理的N2O排放强度最低.因此,复种翻压绿肥配施70%化肥为青海高原春小麦最佳栽培方式.
The field experiments were conducted from 2021 to 2022 to investigate the effects of multi-ple cropping and applying green manure during the autumn fallow period on the yield,soil nitrogen content and N2O emission of spring wheat in Qinghai.A total of six treatments are set up,including conventional fertilization at 100%(F100),70%(F70),0%(F0)and multiple cropping and ap-plying green manure combined with chemical fertilizer at 100%(F100+G),70%(F70+G)and 0%(F0+G).The content of nitrate nitrogen and ammonium nitrogen in the 0~100 cm soil during the seedling,flowering and harvest stages is analyzed under different treatments.The characteristics of N2O emission and wheat yield are analyzed throughout the entire growth period.The results show that the numbers of ears,grains per ear,thousand grain weight and yield of spring wheat are signifi-cantly increased(P<0.05)with the treatment of multiple cropping and applying green manure.The treatment F70+G has the best yield increasing effect,reaching 6 025 kg/hm2.The content of nitrate nitrogen and ammonium nitrogen during the flowering and maturity stages is F70+G>F100+G>F70>F0+G>Fl00>F0.Compared with applying chemical fertilizer alone,the application of mul-tiple cropping and green manure combined with chemical fertilizer can reduce N2O emissions,with the treatment F70+G significantly reducing N2O emission compared to the treatment F70(P<0.05).The treatment F70+G has the lowest N2O emission intensity.Therefore,the optimal cultiva-tion method for spring wheat in Qinghai is to combine multiple cropping with green manure and 70%chemical fertilizer.