摘要
为了研究西南喀斯特山区沼液灌溉氮淋溶风险,以及率定沼液还田安全施用量,以该区域典型土壤——黄壤为供试土壤,主栽作物油菜为供试作物,牛场沼液为施用材料,开展大棚盆栽试验模拟沼液灌溉,评估沼液灌溉氮淋溶风险,考察油菜农艺性状响应,率定沼液安全施用量。设置油菜不施肥(CK)、无作物施沼液(NP480,施氮量480 kg·hm^(-2))、油菜施化肥(CF,480 kg·hm^(-2))、油菜沼液低施用量(R120,120 kg·hm^(-2))、油菜沼液中施用量(R240,240 kg·hm^(-2))、油菜沼液高施用量(R480,480 kg·hm^(-2))6个处理,将化肥水溶或沼液稀释后按每12 d 1次、每次25 mm连续灌入12次。结果表明:沼液灌溉存在氮淋溶风险,该风险以NO_(3)^(-)-N负荷为主,NO_(3)^(-)-N淋溶风险随施氮量增加而增大,R480处理NO_(3)^(-)-N淋溶量分别是CK、R120、R240处理的2、1.8倍和1.4倍;同施氮量下,沼液灌溉氮淋溶风险低于化肥处理,CF处理TN、NH_(4)^(+)-N、NO_(3)^(-)-N淋溶量分别是R480处理的3.8、2.3倍和2.9倍;R480处理的氮淋溶风险值得警惕,但油菜氮素吸收能够降低该风险,使TN、NH_(4)^(+)-N、NO_(3)^(-)-N淋溶量分别降低34%、30%、32%;适量施用沼液(施氮量120 kg·hm^(-2))相对CF处理能改善油菜农艺性状,但过量施用沼液(施氮量480 kg·hm^(-2))不利于油菜生长。研究表明,西南喀斯特山区油菜黄壤沼液灌溉存在一定氮淋溶风险,综合考虑氮淋溶风险、油菜农艺性状和沼液消纳需求,沼液还田施氮量控制在240 kg·hm^(-2)以内为宜。
Biogas slurry is commonly applied through irrigation in the karst mountainous areas of southwest China.However,the resulting leaching of soil nitrogen(N)has yet to be explored,and the environmental threshold of the slurry application rate has yet to be determined.To assess the resulting N leaching and plant growth and the threshold rate of slurry application,a pot experiment was performed in a greenhouse,simulating biogas slurry irrigation using materials including yellow soil,rape,and biogas slurry from a cattle farm.Six treatments were employed,including triplicated pots containing rape plants without N fertilization(CK),containing no plants with slurry application at a rate of 480 kg·hm^(-2)(NP480),pots growing rape plants receiving urea at a rate of 480 kg·hm^(-2)(CF),fertilized with biogas slurry at rates of 120 kg·hm^(-2)(R120),240 kg·hm^(-2)(R240),and 480 kg·hm^(-2)(R480).In each treatment,25 mm of tap water,urea solution,or dilute slurry was applied periodically once every 12 d,for a total of 12 applications.According to our experimental results,biogas slurry irrigation enhanced soil N leaching,predominantly consisting of nitrate(NO_(3)^(-)-N)leaching.The NO_(3)^(-)-N leaching was accelerated by increasing nitrogen application rates,accounting for a total amount of N in the R480 treatment that was 2,1.8,and 1.4 times that in the CK,R120,and R240 treatments,respectively.In addition,the slurry resulted in lower N leaching than that with urea,as demonstrated by the TN,NH_(4)^(+)-N,and NO_(3)^(-)-N leaching in the CF treatment at 3.8,2.3,and 2.9 times that in of the R480 treatment,respectively.Although biogas slurry application at a rate of 480 kg·hm^(-2)(R480)triggered N leaching,34%,30%,and 32%of the resulting TN,NH_(4)^(+)-N,and NO_(3)^(-)-N leaching was likely reduced by plant uptake,respectively.In addition,biogas slurry applied at a moderate rate(R120)promoted rape growth compared with that under chemical fertilizer application;however,too much slurry application(R480)could undermine rape growth.Applying biogas slurry through irrigation to rape plants in the karst mountainous areas of southwest China may enhance N leaching from yellow soil.Furthermore,a slurry application rate lower than 240 kg·hm^(-2) might improve the balance between N leaching control,plant growth enhancement,and slurry recycling.
作者
孙芳芳
江涛
成剑波
何腾兵
秦松
汪国英
洪建明
SUN Fangfang;JIANG Tao;CHENG Jianbo;HE Tengbing;QIN Song;WANG Guoying;HONG Jianming(College of Agriculture,Guizhou University,Guiyang 550025,China;Institute of New Rural Development,Guizhou University,Guiyang 550025,China;Guizhou Engineering Research Center for Technologies in Control and Recycling of Livestock and Poultry Breeding Waste in Mountain Area,Guiyang 550025,China;Soil and Fertilizer Institute,Guizhou Academy of Agricultural Sciences,Guiyang 550006,China;Guizhou Agricultural Ecology and Resources Protection Agency,Guiyang 550001,China;Yuping Agricultural and Rural Bureau,Tongren 554330,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2022年第6期1327-1336,共10页
Journal of Agro-Environment Science
基金
贵州省自然科学基金项目(黔科合基础[2020]1Y191)
贵州省科研机构服务企业行动计划项目(黔科合服企[2018]4007(006))
贵州省国内一流学科建设项目(GNYL[2017]009)
贵州省科技基础条件平台项目([2019]5701)。
关键词
沼液还田
黄壤
油菜
氮淋溶
安全用量
biogas slurry application
yellow soil
rape
nitrogen leaching
application rate threshold
