Long-term straw mulching with nitrogen fertilization increases nutrient and microbial determinants of soil quality in a maize-wheat rotation on China's Loess Plateau
Long-term straw mulching with nitrogen fertilization increases nutrient and microbial determinants of soil quality in a maize-wheat rotation on China's Loess Plateau
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长期秸秆覆盖加氮肥增加了中国黄土高原玉米小麦轮作土壤质量的养分和微生物决定因素
DOI：
10.1016/j.scitotenv.2021.145930
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发表时间：
2021-02-24
影响因子：
9.8
通讯作者：
Zhu, Yuanjun
中科院分区：
文献类型：
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作者：
Chen, Qiuyu;Liu, Zhanjun;Zhu, Yuanjun
在半干旱旱地，覆盖物和氮肥对提高作物产量至关重要。然而，它们对土壤理化性质，胞外酶活性，微生物群落结构的长期影响，因此通过开发土壤质量指数（SQI）的土壤质量仍然在很大程度上未被探索。因此，我们分析了14年后的覆盖（CT，无覆盖; RF，覆膜垄沟和秸秆覆盖沟; SM，秸秆覆盖）和施氮（0，120和240公斤公顷（-1））在中国黄土高原的玉米-小麦轮作处理的土壤。与CT相比，RF和SM显著增加了土壤水分含量（SMC），有机碳（SOC），磷酸酶和总磷脂脂肪酸（PLFA）。与RF相比，SM增加了SOC、全N、速效磷（AP）、速效钾（AK）、β-葡萄糖苷酶、N-乙酰氨基葡萄糖苷酶（NAG）、过氧化物酶、纤维二糖水解酶、革兰氏阴性菌（G（-））和真菌。因此，SQI在SM中最高（0.698），其次是RF（0.642）和CT（0.620）。施氮显著增加了土壤总N、NO3-、微生物生物量N、α-葡萄糖苷酶、NAG、PLFAs总量和G（-），但导致pH、AP、AK和G（+）：G（-）比值显著下降。各施氮处理的SQI值为N240（0.680）> N120（0.650）> N 0（0.630）。土壤有机碳含量与酶活性密切相关，而NO3-、SOC和SMC是调控微生物群落组成的关键变量。结构方程模型表明，覆盖和施氮通过调节土壤速效N、P、K、酶活性和微生物群落结构对SQI有显著的正向影响，覆盖对SQI的总效应（0.62）大于施氮（0.34）。总的来说，在SM + N240处理中观察到的最高SQI表明，秸秆覆盖，而不是塑料薄膜覆盖，结合高氮添加可能是一种可持续的土地管理实践，提高半干旱旱地农业系统的土壤质量。(C)2021爱思唯尔有限公司版权所有。
Mulching and nitrogen (N) fertilization are essential to increase crop yields in semiarid drylands. However, their long-term effects on soil physicochemical properties, extracellular enzyme activities, microbial community structure, and therefore soil quality via developing a soil quality index (SQI) remain largely unexplored. Hence, we analyzed soils after 14 years of mulching (CT, no mulch; RF, plastic film-mulched ridges and straw mulched-furrows; SM, straw mulching) and N fertilization (0, 120 and 240 kg ha(-1)) treatments in a maize-wheat rotation on China's Loess Plateau. Compared with CT, RF and SM significantly increased soil moisture content (SMC), organic carbon (SOC), phosphatase, and total phospholipid fatty acids (PLFAs). Compared with RF, SM increased SOC, total N, available phosphorus (AP), available potassium (AK), beta-glucosidase, N-acetyl-glucosaminidase (NAG), peroxidase, and cellobiohydrolase, gram-negative bacteria (G(-)), and fungi. Consequently, the SQI was highest in SM (0.698), followed by RF (0.642) and CT (0.620). Nitrogen fertilization significantly increased total N, NO3-, microbial biomass N, alpha-glucosidase, NAG, total PLFAs, and G(-), but caused a significant decline in pH, AP, AK, and the G(+):G(-) ratio. Averaged across N-fertilizations, the SQI was ranked N240 (0.680) > N120 (0.650) > N0 (0.630). Redundancy analysis showed that SOC was closely associated with enzyme activities, whereas NO3-, SOC, and SMC were the key variables regulating microbial community composition. Structural equation model indicated that mulching and N fertilization strongly and positively affected SQI by regulating soil available N, P, and K, enzyme activities, and microbial communities, and the total effect of mulching (0.62) on SQI was greater than that of N addition (0.34). Collectively, the highest SQI observed in the SM + N240 treatment suggested that straw mulch, rather than plastic-film mulch, combined with high N addition could be a sustainable land management practice that improves soil quality in semiarid dryland farming systems. (C) 2021 Elsevier B.V. All rights reserved.