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施氮量和土壤含水量对红壤区黑麦草腐解和氮素释放的影响

杨文亭1,2,王晓维1,2,徐健程1,2,焦琪琪1,鲁美娟3,黄国勤1,2*   

  1. 1江西农业大学作物生理生态与遗传育种教育部重点实验室, 南昌 330045;2江西农业大学生态科学研究中心, 南昌 330045;3江西农业大学国土资源与环境学院, 南昌 330045)
  • 出版日期:2018-09-10 发布日期:2018-09-10

Effects of nitrogen application rates and soil water contents on ryegrass decomposition and nitrogen release in red soil.

YANG Wen-ting1,2, WANG Xiao-wei1,2, XU Jian-cheng1,2, JIAO Qi-qi1, LU Mei-juan3, HUANG Guo-qin1,2*   

  1. (1Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang 330045, China; 2Center for Ecological Science Research, Jiangxi Agricultural University, Nanchang 330045, China; 3College of Territorial Resources and Environment, Jiangxi Agricultural University, Nanchang 330045, China).
  • Online:2018-09-10 Published:2018-09-10

摘要: 绿肥还田是主要的农田有机培肥措施之一,外源氮素和土壤含水量是影响绿肥腐解的重要因子。本研究设置土壤含水量(15%、30%、45%)和施氮量(0、60、120 mg·kg-1)两因素三水平的室内培养试验,分析了土壤含水量和施氮量对红壤区黑麦草还田过程中的腐解和氮素释放的影响。结果表明:相同含水量条件下,氮肥的增加没有促进黑麦草的腐解,一定程度上抑制了黑麦草还田7~21 d时的腐解速率;相同施氮水平下,土壤含水量的增加有利于促进黑麦草的腐解率;相同土壤含水量条件下,施氮抑制了黑麦草还田7~13 d时的氮素释放率;相同施氮水平下,土壤含水量的增加促进了黑麦草还田过程中的氮素释放率;黑麦草还田57~91 d时,增加土壤含水量能提高黑麦草氮素释放率,且不施氮较施氮条件下的效果更明显;91 d时,含水量45%和施氮量60 mg·kg-1处理的黑麦草还田腐解率最大,达到0.889,含水量45%和施氮量120 mg·kg-1处理的氮素释放率最高,达到0.885。双因素方差分析结果表明,土壤含水量对黑麦草腐解率和氮素释放率均存在显著影响。综合来看,红壤区黑麦草还田初期需施加一定量的氮素(60 mg·kg-1)和保持合理的土壤含水量(30%),以抑制黑麦草还田前期的腐解;还田后期提高土壤含水量(45%),加快黑麦草后期的腐解和氮素释放,促进下茬作物氮素吸收利用。

关键词: 鱼类群落, 功能丰富度, 功能多样性, 功能离散度, 功能均匀度, 时空变化

Abstract: Green manure returning is one of the main strategies of organic fertilization in cropland. External nitrogen and soil water content are important factors affecting the decomposition of green manure. An incubation experiment with two factors and three levels was conducted to investigate the effects of soil water contents (15%, 30%, 45%) and nitrogen (N) application rates (0, 60, 120 mg·kg-1) on decomposition and N release rate of ryegrass (Lolium multiflorum Lam.) during returning into red soil. Under the same soil water content level, increased N fertilization rate did not promote the decomposition of ryegrass and inhibited the decomposition at 7-21 days, N application limited N release rate at 7-13 days after ryegrass returning. With the same N application rate, the increases of soil water content improved the decomposition rate of ryegrass and promoted N release rate during ryegrass returning. Increasing soil water content enhanced N release rate of ryegrass under ambient N condition compared to under N application in the late stage (57-91 days) of ryegrass returning. At the 91st day, the treatment with 45% water content and 60 mg·kg-1 N application rate had the highest decomposition rate, being up to 0.889, while the treatment of 45% water content and 120 mg·kg-1 N application rate had the highest rate of N released during ryegrass returning, being up to 0.885. The results of twoway ANOVA showed that soil water content had significant effects on the decomposition rate and N release rate of ryegrass. In conclusion, reasonable chemical N fertilization rate (60 mg·kg-1) and soil water content (30%) could inhibit the decomposition and N release during the early stage, while increasing soil water content (45%) could accelerate decomposition and N release during the late stage, and thus improve N uptake and utilization of the succeeding crops.

Key words: fish community, functional richness, functional divergence, functional evenness, functional diversity, spatio-temporal variation.