氮素形态对油菜秸秆腐解及养分释放规律的影响  

Effects of nitrogen forms on decomposition and nutrient release of rapeseed straw

作　　者：李晓韦 韩上 雷之萌 武际[2] 石祖梁 孙志祥 李敏[2] 王慧 唐杉[2] 程文龙 朱林[1] LI Xiaowei;HAN Shang;LEI Zhimeng;WU Ji;SHI Zuliang;SUN Zhixiang;LI Min;WANG Hui;TANG Shan;CHENG Wenlong;ZHU Lin(College of Resources and Environment,Anhui Agricultural University,Hefei 230036,China;Institute of Soil and Fertilizer,Anhui Academy of Agricultural Sciences / Key Laboratory of Nutrient Cycling and Resource Environment of Anhui Province,Hefei 230031,China;Rural Energy and Environment Agency,Ministry of Agriculture and Rural Affairs,Beijing 100125,China)

机构地区：[1]安徽农业大学资源与环境学院,合肥230036 [2]安徽省农业科学院土壤肥料研究所/养分循环与资源环境安徽省重点实验室,合肥230031 [3]农业农村部农业生态与资源保护总站,北京100125

出　　处：《中国生态农业学报（中英文）》2019年第5期717-725,共9页Chinese Journal of Eco-Agriculture

基　　金：公益性行业(农业)科研专项(201503122-06);安徽省对外科技合作项目(1604b0602022);安徽省科技重大专项(17030701055);国家重点研发计划项目(2018YFD0200905)资助~~

摘　　要：采用尼龙网袋研究法,研究了不同形态氮素对油菜秸秆腐解及养分释放规律的影响,以期为农业秸秆循环利用和改善秸秆还田效果提供理论依据。试验设置4 个处理:不添加氮素(CK)、添加尿素(PU)、添加尿素硝酸铵(UAN)和添加石灰氮(CaCN2),周期120 d。结果表明,油菜秸秆腐解表现为前期快(0~30 d)、后期慢(30~120 d)的特征。120 d 时,油菜秸秆累积腐解率为46.08%~52.34%,碳、氮、磷和钾的释放率分别为44.25%~51.52%、51.19%~54.87%、52.82%~58.45%和96.61%~97.46%。添加氮素可以显著促进油菜秸秆腐解。120 d 时,添加氮素处理较CK 处理油菜秸秆的累积腐解率提高10.80%~13.59%。不同形态氮素对秸秆的腐解特征和碳氮磷钾释放速率的效应不同。其中, PU 处理秸秆腐解过程分两个阶段,快速腐解(0~30 d)和缓慢腐解(30~120 d);30 d 时油菜秸秆的腐解率达40.39%, 30 d 后腐解速率逐渐趋于稳定, 120 d 时腐解率达51.06%。UAN处理腐解过程分3 个阶段,快速腐解(0~30 d)、腐解减缓(30~60 d)和缓慢腐解(30~120 d);30 d 时腐解率达40.67%, 30~60 d 腐解率上升7.54%, 120 d 时腐解率为51.63%。CaCN2 处理的秸秆腐解过程分两个阶段,快速腐解(0~30 d)和缓慢腐解(30~120 d);其促进腐解作用主要表现在60 d 后, 60 d 时油菜秸秆腐解率达44.37%,120 d 时腐解率为52.34%。与不施氮处理相比, 120 d 时UAN 处理秸秆累积腐解率提高12.04%,碳、氮和磷累积释放率分别提高9.33%、7.19%和6.97%。各处理对秸秆钾的释放率影响不显著。综合来看,以UAN 促进油菜秸秆腐解的效果较为显著。Excess rape straw causes unreasonable straw processing, such as burning, resulting in resource waste and serious environmental pollution. Returning straw to the soil is an effective way to improve this situation. Previous studies have found that nitrogen can regulate the soil microbial carbon-nitrogen ratio to promote straw decomposition. At present, much research has focused on the effects of nitrogen rate on straw decomposition, whereas the effects of different forms of nitrogen have rarely been proposed. In this experiment, rape straw was returned to soil for 120 days with different forms of nitrogen: urea (PU), urea ammonium nitrate (UAN), and lime nitrogen (CaCN2), at a 90 kg·hm^-2 application rate in nylon net bags. The effects of different forms of nitrogen on the decomposition and nutrient release of rape straw were studied. The straw weight and carbon, nitrogen, phosphorus, and potassium contents of straw residues were investigated at 5, 10, 30, 60, 90, and 120 d after straw mixtures were buried into soil to explore characteristics of straw decomposition and nutrient release with the application of different nitrogen forms. The aim of the study was to optimize straw incorporation into soil to improve straw utilization efficiency. The results showed that the decomposition of rape straw was fast in the early stage (0~30 d) and slow in the later stage (30~120 d). At 120 d, the cumulative decomposition rate of rape straw was 46.08%~52.34%. The release rates of carbon, nitrogen, phosphorus and potassium were 44.25%~51.52%, 51.19%~54.87%, 52.82%~58.45%, and 96.61%~97.46%, respectively. The addition of nitrogen significantly promoted the decomposition of rape straw. At 120 d, the cumulative decomposition rate of nitrogen treatments increased by 10.80%?13.59% than that of the control treatment. Different forms of nitrogen have different effects on straw decomposition and release rates of carbon, nitrogen, phosphorus and potassium. Among them, the PU treatment decomposition process was divided into two stages, r

关 键 词：氮素形态 油菜秸秆 腐解 养分释放 

分 类 号：S38[农业科学—农艺学] S146.1