欢迎访问《环境科学学报》编辑部网站！

快速检索			高级检索

研究论文

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,100ppm、250ppm和500ppm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(100ppm、250ppm、500ppm和1000ppm)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,对于提高肥料的利用率和减少环境污染都具有重大的现实意义。

Abstract：Benzoic acid and p -tert-benzoic acid are two allelochemicals which can be produced from decomposition of crop residue.N₂O 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 N₂O emission from the soil,and the inhibiting effects increase with concentration.At concentrations of 100,250 and 500mg/kg,benzoic acid inhibited 42.78%-67.93% of the N₂O emission when soil moisture was 16.5%.At the same moisture, p -tert-benzoic acid reduced 45.27%-73.42% of N₂O emission,at concentrations of 100,250,500,and 1000mg/kg.While soil moisture was 100%,the two allelochemicals reduced 44.67%-89.78% and 26.40%-77.09% N₂O emission,respectively.In addition,allelochemicals could retard oxidization of NH₄⁺to NO₃^- .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.