γ-聚谷氨酸对土壤水氮运移特性的影响  

Effects ofγ-Polyglutamic Acid on Soil Water and Nitrogen Transport Characteristics

作　　者：石肖肖 史文娟[1] 庞琳娜 文利军 高志永 SHI Xiaoxiao;SHI Wenjuan;PANG Lingna;WEN Lijun;GAO Zhiyong(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi’an University of Technology, Xi’an 710048)

机构地区：[1]西安理工大学省部共建西北旱区生态水利国家重点实验室,西安710048

出　　处：《水土保持学报》2020年第3期190-197,共8页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(51379173);陕西省自然科学基础研究计划项目(2018JM5051);陕西省教育厅重点实验室科研计划项目(16JS085)。

摘　　要：为了明确一种新型的环保型保水缓释剂γ-聚谷氨酸(简称γ-PGA)的节水保肥效应,在施氮量相同情况下(2 g/kg)设置了4种γ-PGA梯度的施加量(0,0.1%,0.2%,0.4%),以0作为对照处理,通过室内一维土柱入渗试验,研究了γ-PGA施加量对土壤氮素迁移特性的影响。结果表明:(1)定水头入渗条件下,累积入渗量、入渗速率、湿润锋迁移的距离均随着γ-PGA施量的增加而逐渐越小,与对照组相比,添加0.4%γ-PGA的试验组其累积入渗量、入渗率和湿润锋迁移的距离分别减少27.64%,73.45%,31.58%;(2)Philip公式模拟结果中,吸渗率S随γ-PGA施量的增加逐渐减小,呈负相关;Kostiakov公式模拟结果中,经验系数K随γ-PGA施量的增加逐渐减小,呈负相关,经验指数a随γ-PGA施量的增加逐渐增大,呈正相关;(3)随着γ-PGA施量的增加,表层土壤(0—15 cm)含水率随着γ-PGA施量的增加而逐渐增大,深层土壤(15 cm以下)则相反;同时,γ-PGA施量越大,同一时期各土层深度硝态氮、铵态氮含量越大,停止供水后的第4天,添加0.1%,0.2%,0.4%γ-PGA的试验组平均硝态氮含量比对照组分别增加29.55%,42.49%,59.50%,平均铵态氮含量比对照组分别增加43.97%,123.40%,156.74%。综上,向土壤中施加γ-PGA可有效减缓水分下渗,将水分更多地聚集在土壤浅层,同时降低肥料淋失率,提高水肥利用率,减少灌溉次数和费用,达到改善土壤结构,提高作物产量的目的。In order toclarify the water-saving and fertilizer-conserving effects of a new environmental sustained-release water-retaining agent,γ-polyglutamic acid(γ-PGA),four kinds ofγ-PGA gradients(0,0.1%,0.2%and 0.4%)were applied at the same nitrogen application rate(2 g/kg),and noγ-PGA was taken as control.The effects ofγ-PGA application rate on soil nitrogen transport characteristics were studied by one-dimensional soil column infiltration experiment in laboratory.The results showed that:(1)Under the condition of constant head infiltration,the cumulative infiltration amount,infiltration rate and the distance of wetting front migration all decreased with the increasing ofγ-PGA application amount.Compared with the control group,the cumulative infiltration amount,infiltration rate,and distance of wet front migration in the experimental group with 0.4%γ-PGA application decreased by 27.64%,73.45%and 31.58%,respectively.(2)According to Philip formula simulation results,the permeability S decreased with the increasing ofγ-PGA application,showing a negative correlation;in the results of Kostiakov formula simulation,empirical coefficient K decreased with the increasing ofγ-PGA application,showing a negative correlation,and empirical index a increased with the increasing ofγ-PGA application,showing a positive correlation.(3)With the increasing ofγ-PGA application,the water content of surface soil(0-15 cm)increased gradually,while that of the deep soil(below 15cm)was the opposite.At the same time,the greater theγ-PGA application amount,the greater the content of nitrate nitrogen and ammonium nitrogen in each soil layer in the same period.On the fourth day after stopping the water supply,the average nitrate nitrogen content of the experimental group added with 0.1%,0.2%and 0.4%γ-PGA,respectively,increased by 29.55%,42.49%and 59.50%compared with thecontrol group,and the average ammonium nitrogen content increased by 43.97%,123.40%and 156.74%.In conclusion,applyingγ-PGA to soil could effectively slow down water infiltr

关 键 词：Γ-PGA 土壤入渗 水氮运移 保水保肥 

分 类 号：S152[农业科学—土壤学]