秸秆还田对土壤还原性和水稻根系生长及产量的影响

发布时间：2018-08-06 21:45

【摘要】：为明确油菜秸秆还田对土壤环境及水稻根系生长的影响,该研究采用田间试验与栽培模拟试验相结合的方法,分析了油菜秸秆还田后,稻田土壤氧化还原电位(EH值)、还原性物质总量和Fe2+含量的变化规律及水稻苗期根系数量、质量、体积、长度和伤流强度等的变化规律。结果表明,1)油菜秸秆覆盖或翻埋条件下,稻田土壤氧化还原电位日均变化量(RCEH值)表现为先降低后增加的趋势,而土壤还原性物质总量日均变化量(RCRRM值)和土壤二价铁含量日均变化量(RCFe值)表现为先增加后降低的趋势;其中水稻移栽后14~18 d土壤RCEH值最低,移栽后10~14 d和14~22 d土壤RCRRM值(0.28~0.62 cmol/(kg·d))和RCFe值(5.0~31.6μg/(kg·d))达到最大。2)油菜秸秆覆盖或翻埋条件下,随着秸秆还田量的增加,水稻根系总量(数量、质量、体积和长度)、白根数量和根系伤流强度显著降低;与覆盖相比,油菜秸秆翻埋对水稻根系伤流日均变化量(RC_(RBI))的影响时间更长,水稻根系体积日均变化量(RCRVT值)和质量日均变化量(RCRQT值)的缓慢增长期延长了4 d。3)水稻移栽后10~22 d,油菜秸秆还田对稻田土壤环境和水稻根系生长的影响最显著;移栽后27~32 d,油菜秸秆还田对水稻根系生长的影响程度显著降低。油菜秸秆还田条件下,随着秸秆还田量增加,水稻苗期的土壤氧化还原电位显著降低,土壤还原性物质总量和Fe2+含量显著增加;水稻根系总量(数量、质量、体积和长度)和根系活力(白根数量和根系伤流强度)显著降低。在四川油稻两熟区,油菜秸秆还田量以全量还田为宜,适宜机械作业的田块以油菜秸秆翻埋还田为宜。
[Abstract]:In order to clarify the effect of rape straw returning to soil environment and rice root growth, the field experiment and cultivation simulation experiment were used to analyze the effect of rape straw on soil environment and rice root growth. The changes of soil redox potential (EH), total amount of reducing matter and Fe2 content, and the changes of root system quantity, mass, volume, length and injury intensity of rice seedlings were studied. The results showed that (1) under the condition of rape straw mulching or burying, the average daily change of redox potential (RCEH) of paddy soil showed a tendency of decreasing first and then increasing. However, the average daily variation of soil total reducing matter (RCRRM) and divalent iron content (RCFe) increased first and then decreased, and the RCEH value of soil was the lowest at 1418 days after rice transplanting. Under the conditions of rape straw mulching or burying, the total root system (quantity and quality) of rice roots increased with the increase of straw returning amount under the condition of soil RCRRM value (0.28 ~ 0.62 cmol/ (kg d) and RCFe value (5.0N 31.6 渭 g / (kg d) reached the maximum at 10 ~ 14 and 1422 days after transplanting. The number of white roots and the intensity of root injury were significantly decreased, compared with mulching, rape straw mulching had a longer effect on the daily variation of root injury (RC _ (RBI). The slow increasing period of root volume (RCRVT) and mass daily variation (RCRQT) was prolonged by 4 days. 3) 1022 days after transplanting rice, the effect of rape straw returning to the field on soil environment and root growth of rice was the most significant. The effect of rape straw returning to the field on the root growth of rice decreased significantly after 27 ~ 32 days of transplanting. Under the condition of returning rape straw to the field, with the increase of straw return, the redox potential of soil at seedling stage of rice decreased significantly, the total amount of soil reducing matter and the content of Fe2 increased significantly, the total amount (quantity, quality) of root system of rice increased significantly. Volume and length) and root activity (white root number and root drainage intensity) decreased significantly. In the oil-rice double cropping area of Sichuan, the suitable amount of rape straw returning to the field is the whole amount, and the suitable field suitable for mechanical operation is rape straw to be turned over and returned to the field.
【作者单位】：西北农林科技大学农学院;西南科技大学生命科学与工程学院;
【基金】：国家自然基金项目(31401347;31601269) 国家粮食丰产增效科技创新项目(2016YFD0300210) 四川省育种攻关项目(2016NYZ0028) 水稻生物学国家重点实验室项目(160202)联合资助
【分类号】：S141.4;S511

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