长期定位施肥下黑土碳排放特征及其碳库组分与酶活性变化

发布时间：2018-03-27 07:43

本文选题：长期施肥　切入点：土壤碳排放量　出处：《生态学报》2017年19期

【摘要】：黑土作为承担我国粮食安全与生态安全的重要土壤资源,其碳排放特征与碳库组分变化一直是生态学领域研究的热点。施肥是影响黑土有机碳输入、输出的重要因素,而这需要长时间尺度的探究。为明确长期不同施肥下的土壤碳排放特征及其影响机制,以始于1990年的国家土壤肥力与肥料效益监测网站黑土监测基地-公主岭为研究平台,选取不施肥(CK)、单施氮磷钾肥(NPK)、无机肥配施低量有机肥(NPKM1)、1.5倍的无机肥配施低量有机肥(1.5(NPKM1))、无机肥配施高量有机肥(NPKM2)和无机肥配施秸秆(NPKS)6个处理,探讨了长期不同施肥下土壤碳排放量(CO2-C)与土壤碳库组分包括水溶性有机碳(DOC)、微生物量碳(MBC)、颗粒有机碳(POC)、易氧化有机碳(ROC)及其β-葡萄糖苷酶(BG)、木聚糖酶(BXYL)、纤维素酶(CBH)和乙酰基β-葡萄糖胺酶(NAG)等酶活性变化。结果表明:与CK相比,各施肥处理均可以显著增加黑土土壤碳排放量(P0.05),其中,NPK处理土壤碳排放量约为2633.33 kg/hm~2,显著高出CK处理37.36%;长期有机无机配施(NPKM1、1.5(NPKM1)、NPKM2)显著增加土壤碳排放量71.81%—88.51%,效果最为明显;NPKS显著增加土壤碳排放量56.32%,并且三种长期有机无机配施措施碳排放差异不显著。相对CK处理,有机无机配施的DOC、MBC、POC、ROC均有显著增加(P0.05),各指标分别高出CK处理16.07%—56.34%、128.84%—185.77%、284.15%—497.45%和841.03%—1145.94%,其中1.5(NPKM1)处理效果最好。同时,有机无机配施相对CK处理的NAG、BG、BXYL和CBH活性分别提高了313.22%—452.65%、129.45%—250.74%、159.08%—273.32%和72.21%—193.53%,且以1.5(NPKM1)处理的效果最好。土壤碳排放量与土壤酶活性、土壤活性碳库组分之间的相关性分析结果表明,长期不同施肥措施的土壤碳排放量不但与土壤ROC、DOC、POC、MBC含量呈极显著相关(P0.001),也与土壤BG、NAG、CBH、BXYL酶活性呈极显著相关(P0.001),说明施肥可以通过改变土壤各活性碳库组分含量与土壤微生物活性影响土壤碳排放量。
[Abstract]:Black soil is an important soil resource for food security and ecological security in China. Its carbon emission characteristics and carbon pool composition changes have been the focus of ecological research. Fertilization is an important factor affecting the input and output of organic carbon in black soil. In order to clarify the characteristics of soil carbon emission and its influence mechanism under long-term and different fertilization, the research platform is based on the National soil Fertility and Fertilizer benefit Monitoring website, Gongzhuling, which started in 1990. The treatments were as follows: no fertilization, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, P, K, N, Soil carbon emissions (CO _ 2-C) and soil carbon pool components under long-term fertilization were studied, including water-soluble organic carbon (DOC), microbial biomass carbon (MBC), particulate organic carbon (POC), easily oxidized organic carbon (ROC), 尾 -glucosidase (BGN), xylanase (BXYL), and cellulase (Cellulase). The activities of CBH) and acetyl 尾 -glucosaminidase (nag) were changed. The results showed that: compared with CK, All fertilization treatments significantly increased soil carbon emissions (P0.05N), in which the soil carbon emissions of the treatments were about 2633.33 kg / hm ~ (2), which was significantly higher than that of CK treatment (37.36%), and the long-term organic and inorganic application of NPKM _ (1 / 1) and NPKM _ (1) + NPK _ (1) + NPKM _ (2) significantly increased the soil carbon emissions (71.81-88.51), and the effect was most obvious. NPKS significantly increased soil carbon emissions, and there was no significant difference in carbon emissions between the three long-term organic and inorganic treatments. The ROC of DOCMBCU POCN with organic and inorganic application increased significantly (P 0.05N), and each index was higher than that of CK treatment (16.07-56.34cm), 128.84% -185.7775%, 284.15-497.45% and 841.03- 1145.94% respectively, and 1.5NPKM1 was the best. Compared with CK treatment, the activities of BXYL and CBH increased by 313.22-452.65, 129.45-250.74um, 159.08-273.32% and 72.21-193.53, respectively. The results of correlation analysis between soil carbon emission and soil enzyme activity and soil active carbon pool showed that. Soil carbon emissions from different fertilization measures were significantly correlated not only with the MBC content of soil ROCDOCPOCN, but also with the enzyme activity of BGNAGNAGN CBHHYL, indicating that fertilization could change the content of soil active carbon pool and the content of soil micro-carbon by changing the content of soil active carbon pool. Biological activity affects soil carbon emissions.
【作者单位】：中国农业科学院农业资源与农业区划研究所;吉林省农业科学院农业环境与资源研究所;
【基金】：公益性行业(农业)科研专项东北地区黑土保育及有机质提升关键技术研究与示范(201303126-2)
【分类号】：S151.9

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