化感物质对土壤N2O释放影响的研究

选用来自作物秸杆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释放的明显的抑制作用，且随着浓度的增大，其抑制效果越显。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

Effect of allelochemicals on N2O emission from soil

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.