水分与温度对塔里木绿洲滴灌棉田土壤氮矿化协同作用机理研究

It is great significance that the total soil organic nitrogen and soluble organic nitrogen transformation and mineralization to southern xinjiang cotton nitrogen balance. it is important factor to the tarim oasis cotton the transformation of soil nitrogen cycle that moisture and temperature.Tarim oasis drip irrigation cotton fields with soil temperature ranger obviously and water resource scarcity to soil organic nitrogen and soluble organic nitrogen mineralization have obvious influence, With top cover PVC resin core training in situ or micro seepage meter regularly intermittent leaching method and temperature and moisture gradient indoor simulation training ideas, tarim oasis drip irrigation cotton soil is the research object, to explore the soil nitrogen mineralization the response mechanism of temperature and moisture. Analysis influence mechanism of temperature and humidity to soil nitrogen mineralization in oasis cotton fields, build the cotton fields soil nitrogen mineralization mechanism model of temperature and humidification in the study area, intends to reveal temperature and moisture cotton for soil organic nitrogen and the influence of soluble organic nitrogen mineralization mechanism in arid areas of the tarim oasis. For the oasis cotton soil fertility, soil maturation and soil fertility continuously stable development, provide important scientific theory basis,it has important theoretical significance and obvious practical significance to tarim oasis soil nitrogen nutrient transformation, balanced fertilization, cotton soil nitrogen cycle and sustainable development of oasis agriculture.

土壤有机氮总量和可溶性有机氮转化及氮矿化问题对南疆棉田氮平衡具有重要意义，土壤水分和温度是影响塔里木绿洲棉田土壤氮循环转化的重要因素。针对塔里木绿洲滴灌棉田土壤有机氮总量和可溶性有机氮相互转化及氮矿化问题从水分和温度入手，研究水分和温度对土壤氮转化影响，用盖顶PVC树脂芯和微型渗漏计原位培养的方法及温度、水分室内模拟生物培养思路，以绿洲滴灌棉田土壤为研究对象，探索土壤有机质总氮量和可溶性有机氮相互转化及氮矿化对温度和水分的响应机理。分析土壤温度、水分及协同作用对土壤氮矿化的作用机理，构建塔里木绿洲棉田土壤氮转化对土壤温度、水分及其协同作用的模型，揭示塔里木干旱区水分和温度对绿洲棉田土壤有机氮和可溶性有机氮矿化的影响机理。为绿洲棉田土壤肥力发展、熟化和地力稳定提供重要的理论依据，对南疆绿洲滴灌棉田土壤氮转化、平衡施肥、氮循环和农业可持续发展具有重要的理论意义和明显的实践指导意义。

【摘要】通过原位培养试验，分析荒漠绿洲垦区三类不同的滴灌棉田（NRC：新垦棉田；AHC：倒茬棉田；CRC：连作棉田）土壤的水分对土壤氮矿化过程和氮矿化速率的影响。结果表明，水分与土壤矿质氮有相关性，土壤氮矿化速率与土壤水分有相关性。土壤水分含量与矿化率呈正相关，同一土层NRC（P>0.05）、AHC（P>0.05）、CRC（P>0.05），相关系数分别为0.1737、0.0130、0.3397，不同时间NRC呈正相关（P<0.05）但AHC、CRC呈负相关，相关系数为0.3133、-0.0196、-0.0682。棉田土壤平均净氮矿化速率，AHC、CRC、NRC分别为0.043、-0.061、0.010kg/(hm2•d)；土壤水分变化对棉田土壤氮矿化有明显的相关性影响，说明在干旱条件下土壤水分能够有效影响土壤氮矿化过程。绿洲滴灌棉田土壤温度对棉田土壤矿质氮含量和氮矿化速率变化的影响，土壤净氮矿化速率与土壤年均温度有明显相关性关系，AHC、CRC、NRC的剖面温度变化和净氮矿化速率呈正相关，相关系数分别为0.0386（P>0.05），0.0165（P>0.05），0.3592 (P>0.05)，棉田土壤平均净氮矿化速率，AHC、CRC、NRC分别为0.0173、-0.0736 、0.0004 kg/（hm2 d）。土壤0～10、10～20、20～30、30～40、40～50 cm五个层次土壤铵态氮含量0.211～5.310 mg kg-1之间，土壤硝态氮含量1.475～82.600 mg kg-1之间。土壤氮矿化量和有机质、容重呈极显著正相关。盆栽试验中随着土壤水分胁迫程度的加剧，棉花植株高度、茎粗均下降。土壤氮矿化量和有机质、容重呈极显著正相关。盆栽试验中随着土壤水分胁迫程度的加剧，棉花株高、茎粗均呈下降趋势。棉花光合CK的日平均净光合速率最高，光照和温度是影响蒸腾速率的主要因素之一棉花叶片水分利用效率与净光合速率、气孔导度存在极显著正相关。