Yang Lijie, Zhang Lili, Yu Chunxiao, Li Dongpo, Gong Ping, Xue Yan, Song Yuchao, Cui Yalan, Doane Timothy A, Wu Zhijie
National Nutrition and Engineering Lab, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang Liaoning, China.
Graduate School, University of Chinese Academy of Sciences, Beijing, China.
PLoS One. 2017 Jan 3;12(1):e0169016. doi: 10.1371/journal.pone.0169016. eCollection 2017.
This study investigated the influence of nitrogen (N) fertilizer and straw on intact amino acid N uptake by soil microorganisms and the relationship between amino acid turnover and soil properties during the wheat growing season. A wheat pot experiment was carried out with three treatments: control (CK), N fertilizer (NF) and N fertilizer plus rice straw (NS). We used stable isotope compound-specific analysis to determine the uptake of 13C,15N-glycine by soil microorganisms. In the NF treatment, microbial 13C,15N-glycine uptake was lower compared with CK, suggesting that inorganic N was the preferred N source for soil microorganisms. However, The application of straw with N fertilizer (in NS treatment) increased microbial 13C,15N-glycine uptake even with the same amount of N fertilizer application. In this treatment, enzyme activities, soil microbial biomass C and microbial biomass N increased simultaneously because more C was available. Soil mineral N and plant N contents all decreased substantially. The increased uptake of intact 13C,15N-glycine in the NS treatment can be attributed to direct assimilation by soil microorganisms to satisfy the demand for N when inorganic N was consumed.
本研究调查了氮肥和秸秆对土壤微生物吸收完整氨基酸氮的影响，以及小麦生长季节氨基酸周转与土壤性质之间的关系。进行了一项小麦盆栽试验，设置了三个处理：对照（CK）、氮肥（NF）和氮肥加稻草（NS）。我们采用稳定同位素化合物特异性分析来测定土壤微生物对13C、15N-甘氨酸的吸收。在NF处理中，微生物对13C、15N-甘氨酸的吸收低于CK，这表明无机氮是土壤微生物的首选氮源。然而，氮肥与秸秆一起施用（NS处理），即使施氮量相同，也增加了微生物对13C、15N-甘氨酸的吸收。在该处理中，由于有更多的碳可用，酶活性、土壤微生物生物量碳和微生物生物量氮同时增加。土壤矿质氮和植物氮含量均大幅下降。NS处理中完整的13C、15N-甘氨酸吸收增加可归因于土壤微生物的直接同化作用，以在无机氮被消耗时满足对氮的需求。
