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以宁夏新垦的淡灰钙土为对象,研究了蚕豆/玉米间作系统不同施氮水平下土壤活性有机碳、氮的时空变异特征。结果表明:新垦淡灰钙土土壤微生物量碳、氮(SMBC、SMBN)及可溶性有机碳、氮(SOC、SON)等活性有机碳、氮含量较低;随着施氮量的增加土壤SMBC含量显著增加;玉米收获期土壤SMBC、SMBN含量显著高于蚕豆收获期;土壤SMBC、SMBN含量空间变异为:蚕豆行间(F-F)含量最高,玉米行(M)、玉米行间(M-M)最低。与不施氮相比,施氮显著提高了蚕豆收获期土壤SOC、SON含量,而玉米收获期各施氮水平间土壤SOC和SON含量无明显差异;土壤SOC、SON的空间变异为:玉米行间>蚕豆行间、蚕豆行(F)、蚕豆与玉米行间(F-M)>玉米行。玉米收获期土壤SMBC及SMBN含量的显著增加,说明土壤微生物对矿质氮的固持对于新垦土壤肥力的提高具有重要作用。
Taking the lightly-calcareous soil reclaimed in Ningxia as the object, the spatio-temporal variations of soil active organic carbon and nitrogen at different nitrogen levels in broad bean / maize intercropping system were studied. The results showed that the contents of soil active microbial biomass C and N, such as SMBC, SMBN, SOC and SON, were relatively low. With the increase of nitrogen application rate, SMBC The contents of SMBC and SMBN in maize were significantly higher than those in faba bean at the harvest stage. The spatial variation of SMBC and SMBN in soil was the highest in FF, while the lowest in maize (M) and the lowest in maize . Compared with no nitrogen application, nitrogen application significantly increased soil SOC and SON content during harvest, but no significant differences were found in SOC and SON contents between different nitrogen application rates at harvest stage. Soil SOC and SON spatial variability were: Between> broad bean line, broad bean line (F), broad bean and corn line (FM)> corn line. The significant increase of soil SMBC and SMBN at the harvest stage of corn shows that the holding of mineral nitrogen by soil microorganism plays an important role in the improvement of soil fertility of new cultivated land.