氮肥分施次数及硝化抑制剂对盆栽玉米N2O排放的影响  

Effects of Nitrogen Fertilizer Application Times and Nitrification Inhibitor on NO Emission from Potted Maize

作　　者：符佩娇 吉恒宽 何秋香 汤水荣 王鸿浩 伍延正 孟磊[1] FU Pei-jiao;JI Heng-kuan;HE Qiu-xiang;TANG Shui-rong;WANG Hong-hao;WU Yan-zheng;MENG Lei(College of Tropical Crops,Hainan University,Haikou 570228,China)

机构地区：[1]海南大学热带作物学院,海口570228

出　　处：《环境科学》2021年第9期4538-4547,共10页Environmental Science

基　　金：国家自然科学基金项目(41661051,42067008);海南省自然科学基金高层次人才项目(320RC493)。

摘　　要：合理施氮是获得较高目标产量和降低因氮环境污染的重要策略.通过盆栽试验研究等氮量下不同分施次数对玉米产量及土壤N_(2)O排放的影响,并探讨氮转化功能基因丰度与N_(2)O排放的关系.本试验设空白(CK,不施尿素)、一次性施氮(S1,将0.5 g·kg^(-1)尿素一次性施入土壤+硝化抑制剂)、二次分施(S2,将0.5 g·kg^(-1)尿素分40%和60%两次施入土壤)和三次分施(S3,将0.5 g·kg^(-1)尿素分20%、40%和40%3次施入土壤).结果表明:(1)施氮促进土壤酸化,氮分施次数造成土壤酸化程度的显著差异,氮分施次数越多,土壤酸化越强.施氮显著提高鲜食玉米果穗产量及茎秆生物量,但氮肥分施次数对土壤pH影响的差异可能会导致植物对氮的吸收利用程度也存在着差异.S3处理显著降低土壤pH的同时,也降低了植物氮吸收累积量和氮素利用效率,也造成了高的N_(2)O累积排放量.与S3处理相比,S1和S2处理分别增产了40.21%和42.55%,其N_(2)O累积排放量也分别显著降低了79.4%和20.9%.(2)N_(2)O排放与AOB和nir K基因丰度呈显著正相关关系,AOB和nirK是N_(2)O排放的主要贡献者.S1处理显著降低了AOB和nir K基因丰度,降低N_(2)O排放,S2和S3处理施肥后显著增加了nirK和nirS基因丰度,降低了nos Z基因丰度,促进了N_(2)O的排放.氮分施次数影响氮转化过程的功能基因,从而影响N_(2)O排放.由此可见,尿素配合DCD一次性施入不仅能保证玉米产量,提高氮素利用效率,还能降低温室气体排放,可作为海南地区鲜食玉米种植过程推荐的施肥模式.Rational application of nitrogen is an important strategy for increasing yield while reducing environmental pollution due to nitrogen. Pot experiments were conducted to study the effects of different application times on maize yield and soil N_(2)O emission under conditions of equal nitrogen content,and to explore the relationship between the abundance of nitrogen conversion functional genes and N_(2)O emission. Four treatments were used,namely a control( CK,no urea),one-time application( S1,one application of 0. 5 g·kg^(-1) urea + nitrification inhibitor),two separate applications [S2,two applications of 0. 5 g·kg^(-1) urea( 40% and 60% respectively) ]and three separate applications( S3,0. 5 g·kg^(-1) urea was divided into three different applications: 20%,40% and 40% respectively).The results showed that:(1) nitrogen application promoted soil acidification,and the degree of soil acidification varied significantly with different application times. More applications of nitrogen led to stronger soil acidification. Nitrogen application significantly increased the ear yield and stem biomass of fresh table maize,but different nitrogen application times may alter soil pH,leading to differences in the degree of nitrogen uptake and utilization in plants. While the S3 treatment significantly reduced soil pH,it also reduced the cumulative nitrogen uptake and utilization in the plants,resulting in a high cumulative N_(2)O emission. Compared with the S3 treatment,the yield was 40. 21% and 42. 55% higher in the S1 and S2 treatments,and the cumulative N_(2)O emission decreased by 79. 4% and20. 9%,respectively.(2) N_(2)O emission was positively correlated with the abundance of AOB and nirK genes,which were the main contributors to N_(2)O emission. S1 significantly decreased the abundance of AOB and nir K genes and N_(2)O emissions,while S2 and S3 significantly increased the abundance of nir K and nir S genes and decreased the abundance of nos Z genes after fertilization,promoting N_(2)O emissions. Nitrogen application times

关 键 词：施肥次数 玉米产量 氮利用效率 N2O排放 功能基因 

分 类 号：X144[环境科学与工程—环境科学]