垄作对降低黄土高原南部冬小麦田氨挥发风险的影响  

Effects of Ridge Tillage Practices on Reducing Ammonia Volatilization from Winter Wheat Fields in Southern Loess Plateau of China

作　　者：杨阳[1] 李娜[1] 王林权[1] 赵玉霞[1] 李雪芳[1] 周芳[1] 王文岩[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《环境科学研究》2015年第3期431-439,共9页Research of Environmental Sciences

基　　金：农业部2012年农业科研杰出人才及其创新团队培养计划项目

摘　　要：为研究黄土高原南部冬小麦田NH3挥发对垄作的响应,揭示其释放机制及污染风险,于2011—2013年冬小麦生长季,按照随机裂区试验设计布置田间试验,采用通气式田间原位酸吸收方法测定NH3挥发.主区为常规栽培及3种垄作,副区为2种施N（氮）处理——未施N（0 kg/hm2,以N计）和施N（180 kg/hm2）.结果表明：不同施N处理下,各耕作模式NH3挥发通量在施肥后10 d均达到峰值,在施肥后30 d稳定在较低水平.垄作单季NH3累积挥发量（以N计）平均值为5.748 kg/hm2,比常规栽培降低4.9%;施N处理下NH3累积挥发量平均值为6.512 kg/hm2,比未施N处理提高26.8%.氮肥NH3挥发损失率为0.47%~1.38%,其中垄作平均损失率比常规栽培降低60.1%.不同施N处理下,各耕作模式NH3挥发通量与土壤w（NH4＋）、含水量呈正相关;与25 cm深度处土壤温度、p H在冬前（施肥播种至土壤结冰阶段）呈正相关,而在冬后（土壤解冻至小麦收获阶段）则呈负相关.土壤w（NH4＋）和土壤温度是控制NH3挥发的两大主要因素.冬前垄作降低NH3挥发通量主要是由于垄作集中深施肥会增加NH3挥发扩散阻力所致.可见,旱作冬小麦种植区采用垄作可降低NH3挥发风险.This study aims to assess the response of ammonia（ NH3） volatilization to ridge tillage practices in a winter wheat（ Triticum aestivum L.） field in the southern Loess Plateau,China.A two-year field experiment was conducted from 2011 to 2013 in the winter wheat growing seasons.The experiment was designed as a split-plot style with tillage practices as main plots.There were three ridge tillage practices and conventional tillage（ CT） as the control.Nitrogen application rates were subplots,namely 0 and 180 kg/hm2.Ammonia volatilization was trapped using vented acid trapping methods,and ammonium（ NH4＋-N） was measured using a continuous flow analyzer.Relationships between NH3 flux and five soil parameters were analyzed by linear regression and stepwise multiple linear regression.The parameters were soil NH4＋,moisture,temperature,p H and organic carbon.The results showed that NH3 flux peaked during the first 10 d following fertilizer application,reduced rapidly in the next 20 d and then leveled off.Ammonia emissions in the ridge tillage systems were on average 5.748 kg/hm2,4.9% less than that in CT（ 6.05 kg/hm2）.In treatments fertilized with 180 kg/hm2nitrogen fertilizer,ammonia emissions averaged 6.512 kg/hm2,26.8% greater than the unfertilized plots.Nitrogen loss rates varied from 0.47% to 1.38%,and the average loss rate in the ridge tillage systems was 60.1% lower than that in CT.Ammonia flux was positively correlated with soil NH4＋and moisture.Ammonia flux was positively correlated with soil temperature and p H from October to December.However,it was negatively correlated with the variables from February to June.Overall, soil NH4＋and temperature were two major factors controlling NH3 flux in winter wheat fields.The extent of ammonia fluxes linked to soil NH4＋was significantly reduced by ridge tillage practices.Therefore,extending ridge tillage practices is recommended in rain-fed winter wheat production in the southern Loess Plateau to mitigate NH3 volatilization.Further verificationswi

关 键 词：垄作 通气式酸吸收装置 氨挥发 土壤w(NH4+) 土壤温度 黄土高原 

分 类 号：X511[环境科学与工程—环境工程]