基于粮草轮作的苜蓿地土壤水氮耦合机理研究

项目名称： 基于粮草轮作的苜蓿地土壤水氮耦合机理研究

项目编号： No.41461067

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 地质学

项目作者： 罗珠珠

作者单位： 甘肃农业大学

项目金额： 51万元

中文摘要： 西部黄土高原区是中国乃至世界上水土流失最严重的区域。以小麦和玉米轮作为主的传统农业措施和资源过度开发利用是导致水土流失的主要原因之一，加之降水变率大，气候条件恶劣，导致农业生产产量低而不稳，农业系统稳定性差。在传统的农业系统中，引入豆科牧草，通过豆科牧草的固氮功能，可有效地提高系统氮素利用效率并改善土壤结构。紫花苜蓿作为优良豆科牧草，在该区生态环境建设和产业结构调整中发挥着重要的作用。因此，本研究以苜蓿草地深层土壤水分和氮素为主要研究对象，以时间和空间的变化为研究尺度，对苜蓿在不同降雨区的生态恢复功能和农业系统中的作用进行研究，探索基于粮草轮作的苜蓿草地水氮耦合机理，以促进苜蓿-粮食作物轮作系统和黄土高原生态恢复进程中土壤水分和氮素的高效利用，为黄土高原半干旱区苜蓿草地可持续利用和旱地作物稳产提供科学依据。

中文关键词： 粮草轮作；土壤水分；土壤氮素；紫花苜蓿

英文摘要： The Loess Plateau is the serious water losses and soil erosion area. Wheat-maize rotation system was the main traditional farming system in the region. For the natural resource shortage and soil degraded, peoples always overuse the resource result in the environment damaged. Low water resource and more variation of annual/seasonal rainfall made the crop production output lower and input higher. Introduce legume crop into the current farming system could improve soil structure and increase soil nutrition through the nitrogen fixation. Lucerne (Medicago sativa L.), is the most nutritious perennial plant with the highest nutrient value as a forage, which played an important role in industrial structure adjustment and ecological environment construction in loess plateau.However, perennial pastures reduce soil moisture content to very low levels and it is difficult to restore soil moisture of desiccated soil layers for a long time. Based on a long-term field experiments conducted in Dingxi City and Qingyang City, Gansu Province, the study investigate and analyze soil water consumption characteristics and nitrogeon movment of deep soil profile on different growth age lucerne grasslands at different precipitation amount.The study aims to anasysis soil water and nitrogeon coupling mechanism for alfalfa pasture and improve utilization rate of soil water and nitrogen in rainfed cropping systems where lucerne grown in rotation with annual crops. As a result, it could give a theoretical base for sustainable utilization of Lucerne grasslands and stable yields of dryland cereal crop in semi-arid areas of loess plateau.

英文关键词： Cereal-forage rotation system;Soil moisture;Soil nitrogeon;Alfafa