不同施氮量下玉米根茬分解及对土壤有机碳的影响

发布时间：2018-07-01 07:50

  本文选题：施氮量 + 根茬碳分解　； 参考：《西北农业学报》2017年10期

【摘要】：通过田间埋藏分解试验,比较3种施氮量(0、120和240kg·hm~(-2))处理的玉米根茬分别与土娄土和黑垆土混合后,在土壤中分解1a期间根茬碳分解差异,并利用碳稳定同位素δ~(13) C方法,研究根茬碳分解对土壤有机碳的贡献。结果显示:杨凌地区水热条件较好,试验期间降水量总和较长武高215mm;杨凌试验地15cm和45cm土层平均温度分别较长武高3.2℃和4.2℃。分解1a后,黑垆土中根茬残留碳量较土娄土中高20.9%~43.6%。根茬来源的土壤有机碳比例在土娄土、黑垆土中分别为22.4%~44.7%和27.4%~38.3%。在黑垆土中,玉米根茬分解1a后,根茬来源的土壤有机碳质量分数显著高于在土娄土中,而在3种不同施氮量处理的玉米根茬之间,根茬来源的土壤有机碳质量分数差异不显著。研究表明,水热条件相对较好的土壤环境能够促进玉米根茬残体的分解矿化,而土壤深度、质地、施肥状况等会影响有机残体还田腐解与土壤有机碳的更新。
[Abstract]:Field burial decomposition experiments were conducted to compare the difference of root carbon decomposition between three treatments (0120 and 240kg hm ~ (-2) after mixing with low soil and black loessial soil, respectively, and using the stable isotope 未 ~ (13) C method. The contribution of stubble carbon decomposition to soil organic carbon was studied. The results show that the water and thermal conditions in Yang Ling area are better, the summation of precipitation during the test period is 215mm higher than that of Changwu, and the average soil temperature of 15cm and 45cm is 3.2 鈩，

本文编号：2087072