黄土高原不同粮草种植模式土壤碳氮及土壤酶活性

发布时间：2018-05-30 04:19

本文选题：黄土高原 + 草田轮作　；参考：《草业科学》2017年11期

【摘要】：通过在陇中黄土高原半干旱区对苜蓿(Medicago sativa)-作物轮作地进行长期定位试验,探讨不同种植模式对土壤碳氮形态及其相关酶活性的影响。6种种植模式分别为苜蓿-苜蓿、苜蓿-休闲、苜蓿-小麦(Triticum aestivum)、苜蓿-玉米(Zea mays)、苜蓿-马铃薯(Solanum tuberosum)和苜蓿-谷子(Setaria italica)。结果表明,苜蓿-作物种植模式不利于土壤总有机碳的积累,而苜蓿翻耕后保持休闲则可维持较高的有机碳含量;与苜蓿连作相比,苜蓿-作物种植模式的土壤有机碳降低了1.60%~23.11%,全氮含量增加了3.81%~21.83%。不同作物对土壤养分吸收利用状况不同,进而引起土壤酶发生变化。与苜蓿连作相比,苜蓿粮食作物种植模式在降低土壤过氧化氢酶和蛋白酶活性的同时,提高了土壤硝酸还原酶活性;其中土壤过氧化氢酶活性和蛋白酶活性分别降低了5.20%~12.30%和15.03%~43.43%,硝酸还原酶活性提高了1.26%~28.79%。苜蓿连作和苜蓿-粮食作物种植模式间的土壤脲酶活性无显著差异(P0.05),但均高于苜蓿-休闲处理。相关性分析结果表明,土壤脲酶活性与土壤有机碳、全氮含量呈显著正相关(P0.05),可作为衡量土壤肥力的指标。
[Abstract]:Based on the long-term localizing experiment on alfalfa Medicago sativa crop rotation in the semi-arid region of Longzhong Loess Plateau, the effects of different planting patterns on soil carbon and nitrogen forms and related enzyme activities were discussed. The six planting patterns were alfalfa and alfalfa, respectively. Alfalfa, triticum aestivum, alfalfa, corn, alfalfa, potato, Solanum tuberosumsuma and alfalfa, Setaria italica. The results showed that the alfalfa crop planting pattern was not conducive to the accumulation of soil total organic carbon, while the higher organic carbon content could be maintained after alfalfa tillage, compared with alfalfa continuous cropping. The soil organic carbon of alfalfa-crop planting model decreased by 1.60% and 23.11%, and the total nitrogen content increased by 3.81% and 21.83% respectively. The absorption and utilization of soil nutrients were different among different crops, which resulted in the change of soil enzymes. Compared with alfalfa continuous cropping, alfalfa grain crop cultivation mode decreased soil catalase and protease activity, and increased soil nitrate reductase activity. The activity of catalase and protease in soil decreased by 5.20% 12.30% and 15.03%, respectively, and the nitrate reductase activity increased by 1.26% and 28.79%, respectively. There was no significant difference in soil urease activity between alfalfa continuous cropping and alfalfa-grain crop planting patterns, but both were higher than alfalfa-fallow treatment. The results of correlation analysis showed that soil urease activity was positively correlated with soil organic carbon and total nitrogen content, and could be used as an index to measure soil fertility.
【作者单位】：甘肃农业大学资源与环境学院;甘肃省干旱生境作物学省部共建国家重点实验室;
【基金】：国家自然科学基金(41461067;31171513) 甘肃省自然科学基金(1606RJZA076;1506RJZA003) 甘肃省财政厅高校基本科研业务费项目(037-041014)
【分类号】：S153.6;S154.2

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