We conducted an experiment with five treatments in winter wheat of the dryland of Northwest China, i.e. 30 t·hm-2 cow dung (M) plus different doses of nitrogen fertilizer (0, 75, 150, 225, and 300 kg N·hm-2), denoted by M+N0, M+N75, M+N150, M+N225, and M+N300, respectively. After three years of treatment, wheat yield, grain quality, and soil biological characteristics were measured in two consecutive years (2018 and 2019). The results showed that the combination of manure with nitrogen fertilizer significantly increased wheat yield compared with the manure-only treatment (M+N0). Compared with the manure-only treatment, the combined treatments significantly increased wheat grain protein content, wet gluten, sedimentation value, and extensibility, but not for starch content. Neither wheat yield nor grain quality had significant differences among the M+N150, M+N225, and M+N300 treatments, but both were prominently higher than those of M+N75. Soil microbial biomass carbon (MBC) and nitrogen (MBN) reached highest in M+N150 for both years, which were distinctly higher than those of M+N0, M+N225, and M+N300. In 2018, soil β-1, 4-glucosidase, cellobiohydrolase, L-leucine aminopeptidase, β-1,4-N-acetyl glucosaminidase, and alkaline phosphatase activities in M+N150 treatment were higher than those of other treatments. In 2019, soil enzyme activities (excluding L-leucine aminopeptidase) in M+N150 were higher than those of M+N0 and M+N225. MBC significantly positively correlated with MBN, and both significantly positively correlated with the activities of cellobiohydrolase, β-1, 4-N-acetyl glucosaminidase, and alkaline phosphatase. MBN significantly positively correlated with total nitrogen content and negatively correlated with NO3-. Considering winter wheat yield, grain quality, and soil biological characteristics, M+N150 was conducive to sustainable production of winter wheat in drylands of Northwest China.
在西北旱地冬小麦进行有机肥和化肥配施试验,共设5个处理,有机肥(牛粪,M)施用量30 t·hm-2,配以不同量的化学氮肥(0、75、150、225、300 kg N·hm-2,分别用M+N0、M+N75、M+N150、M+N225、M+N300表示)。试验进行3年后,连续两年(2018、2019年)测定小麦产量、品质和土壤生物学特性。结果表明: 有机肥配施氮肥小麦产量均显著高于单施有机肥的M+N0处理;M+N150、M+N225和M+N300 3个处理产量均显著高于M+N75处理,3个处理之间差异不显著。除淀粉含量外,有机肥配施氮肥小麦籽粒粗蛋白含量、湿面筋含量、沉降值、延伸性均显著高于M+N0处理,且M+N150、M+N225、M+N300处理均显著高于M+N75处理,但3个处理之间差异不显著。M+N150处理两年的土壤微生物生物量碳氮均最高,显著高于M+N0、M+N225、M+N300处理。2018年M+N150处理β-1,4-葡萄糖苷酶(βG)、纤维二糖水解酶(CBH)、L-亮氨酸氨基肽酶(LAP)、β-1,4-N-乙酰基氨基葡萄糖苷酶(NAG)、碱性磷酸酶(AKP)活性均显著高于其他处理;2019年,除L-亮氨酸氨基肽酶活性外,M+N150处理的其他酶活性均显著高于M+N0和M+N225处理。相关分析显示,MBC与MBN呈极显著正相关,MBC、MBN与CBH、NAG、AKP均呈显著正相关,MBN与TN呈显著正相关、与NO3-呈显著负相关。综合考虑冬小麦产量、品质、土壤生物学特性等因素,M+N150更有利于西北旱地麦田的可持续利用。.
Keywords: nitrogen fertilizer; organic fertilizer; quality; soil enzyme activity; soil microbial biomass; wheat; yield.