化感物质对土壤N_2O释放影响的研究  

Effect of allelochemicals on N\-2O emission from soil

作　　者：黄益宗[1] 张福珠[1] 刘淑琴[1] 曹美秋[1] 

机构地区：[1]中国科学院生态环境研究中心,北京100085

出　　处：《环境科学学报》1999年第5期478-482,共5页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金

摘　　要：选用来自作物秸秆腐解过程中产生的化感物质（ 苯甲酸和对叔丁基苯甲酸） ，在不同浓度和水分条件下对其减少施用尿素土壤中Ｎ２Ｏ 释放的影响进行了研究．结果表明，化感物质对土壤Ｎ２Ｏ释放有明显的抑制作用，且随着浓度的增大，其抑制效果越显著．在土壤水分为１６５ ％ 的状态下，１００ ｐｐｍ 、２５０ ｐｐｍ 和５００ ｐｐｍ 浓度的苯甲酸处理（ 培养温度２５—３０℃） 可减少４７４ ％ —７５３％ Ｎ２Ｏ 从土壤中释放；而当土壤水分为１００ ％ 状态时，上述浓度处理可减少５０２ ％ —９１１ ％ 左右．当培养温度为１８ —２０ ℃时，对叔丁基苯甲酸的不同浓度处理（１００ ｐｐｍ 、２５０ ｐｐｍ 、５００ ｐｐｍ 和１０００ ｐｐｍ） 在土壤水分１６５％ 和１００ ％时，可分别减少４７８ ％ —７４９ ％ 和２８８％ —７８１％ Ｎ２Ｏ 释放．试验还表明，化感物质可减缓土壤中ＮＨ４ ＋ 向ＮＯ３ － 氧化，使尿素水解后释出的氨能在土壤中保持时间更长。Benzoic acid and p \|tert\|benzoic acid are two allelochemicals which can be produced from decomposition of crop residue.N\-2O emission from soil was determined at various soil moistures when the two allelochemicals were applied at various concentration.The results showed that the allelochemicals could inhibit N\-2O emission from the soil,and the inhibiting effects increase with concentration.At concentrations of 100,250 and 500?mg/kg,benzoic acid inhibited 42.78%—67.93% of the N\-2O emission when soil moisture was 16.5%.At the same moisture, p \|tert\|benzoic acid reduced 45.27%—73.42% of N\-2O emission,at concentrations of 100,250,500,and 1000?mg/kg.While soil moisture was 100%,the two allelochemicals reduced 44.67%—89.78% and 26.40%—77.09% N\-2O emission,respectively.In addition,allelochemicals could retard oxidization of NH\-4\++ to NO\-3\+-.Therefore,as one of hydrolystates of urea,ammonia could retain longer in soil.Application of allelochemicals would improve the efficiency of fertilization and reduce environmental pollution.

关 键 词：化感物质 土壤污染 二氧化氮释放 影响分析 

分 类 号：X53[环境科学与工程—环境工程]