【摘要】 通过温室盆栽试验,施用猪粪堆肥(PC)、污泥堆肥(SC)、菜籽饼肥(CM)和无机化肥(IF)后,对土壤pH值和不同形态氮素的短期响应进行研究,探讨土壤可溶性无机氮、有机氮及土壤pH值之间的相互关系。结果表明,CM,PC和IF处理的pH值都呈现先快速下降后缓慢回升的趋势,但PC处理下降幅度较小;而SC处理和不施肥对照(CK)处理的pH值基本不变;不同施肥处理均提高了土壤中氮素水平,3种有机肥中以CM处理最显著地提高了土壤中总可溶性氮(TDN)、NH4+-N、NO3--N和可溶性有机氮(DON)浓度,PC处理的次之,SC处理的最弱,而IF处理与CM处理提高幅度相似。不同施肥处理中土壤可溶性氮表现出不同的短期响应,IF处理和CM处理的TDN分别经过11,13d的稳定期后迅速上升到一个较高的水平,至31d开始下降;PC处理和SC处理未出现突然升高的现象,而是前20d较稳定在一定的范围内波动,之后缓慢下降,总体与对照趋势一致。不同处理土壤中NH4+-N均呈下降趋势;IF处理、CM处理的NO3--N呈增加趋势,PC处理的呈先增加后降低趋势,而SC处理的呈缓慢下降趋势,结果说明不同有机肥在土壤中的转化存在明显的差异。相关性分析显示,CM处理、IF处理的土壤pH值与NH4+-N呈极显著正相关,而与NO3--N呈极显著负相关;除PC处理外,其他处理的DON含量与TDN具有显著正相关性,而PC处理的DON同时与NH4+-N、NO3--N呈显著负相关。更多还原

【Abstract】 The short-term changes of soil dissolved nitrogen and soil pH after fertilizations were studied by pot experiment in greenhouse.The study aimed to discuss the conversion between organic and mineral nitrogen,so as to evaluate the interrelationships between dissolved nitrogen and pH after fertilization in soil.During the five weeks after Brassica chinensis were transplanted into soil amended with different nitrogen fertilizers,soil pH of cake manure,pig compost and inorganic fertilizer treatments followed sharp decreases with slow rebound;sludge compost and control treatments almost didn’t alter pH.Total dissolved nitrogen(TDN),dissolved organic nitrogen(DON),NH+4-N and NO-3-N in soil under different fertilizations followed the sequence: Cake manure,inorganic fertilizer >pig compost >sludge compost >control.NH+4-N declined on the whole,while the rise trends of NO-3-N differed among four fertilization treatments.The results represent transformations of different organic fertilizers varied obviously in soil.Soil pH of cake manure and inorganic fertilizer treatments were significantly positive correlation with NH+4-N,while negative with NO-3-N;except that DON of pig compost treatment was correlated with both NH+4-N and NO-3-N negatively,the other four treatments all had significant postive correlation with TDN.更多还原