北方旱地农业研究的进展与思考

Progress and Consideration of Dryland Farming Research In North China

北方旱地农业是指沿昆仑山—秦岭—淮河一线以北的干旱，半干旱和半湿润易旱地区的、依靠天然降水补充灌溉的农业。该区域土地面积占国土总面积的５６％；耕地面积７．７亿亩，占全国总耕地面积的５１％。本区土地资源丰富，光热充足，但干旱少雨，植改覆盖度差，沙化及水土流失严重，生态环境脆弱。水分胁迫和土壤贫瘠严重地威胁着农业生产发展。依据北方旱区农业发展应坚持种草种树、发展畜牧业、坚持山水田草林综合治理、推行旱作农业技术，促进农林牧和多种经营全面发展的指导思想，北方旱地农业研究在以蓄水保墒和提高水分利用效率为中心的耕作改制、土壤培肥与施肥技术、土壤与作物的水分管理、农业节水技术、作物抗旱生理与抗旱作物的品种选育、旱区综合治理与旱地农业综合增产技术体系等方面均取得了重要进展。认真总结经验，加快成果转化，提出并开展新的具有全局性、方向性的，诸如不同类型旱区农田水分动态平衡，水—土—光—热—气—植（物）农业生态系统动态规律及调控、主要旱地作物的需水规律、提高降水及水资源生产力的综合技术及土地利用与水保措施的优化组合、提高旱区主要作物抗旱性的原理方法、开发抗旱品种资源、建立持续农业技术体系、农业生态良性循环机制，旱区农业应变性等等?

Dryland farming in the northern part of China refers to agriculture de-pending on natrural rainfall and irrigation of dryland in the arid and semiarid areas andsemihumid area liable to drought along the northern part of the Kunlung Mountains,theQinling Mountains and the Huaihe River. The area in this vast region covers 56% of to-tal national area. The cultivated area in this region is 770 million mu, consisting of 51%of total cultivated area of the country. Nature is generous in giving this region rich natu-ral resources and plenty of light and heat,but with more droughts and less rainfall sothat vegetation cover is low and there are also serious desertification,water and soil ero-sion as well as weak ecoenvironment.Soil moisture and soil stress eriously threats thedevelopment of agricultural production. Based on the agrodevelopment in arid area ofnorth China, such guiding thinking should be insisted on as planting trees and grasses,developing livestock production,sticking to the comprehensive management of moun-tains,waters,farmlands, grasses and forests. implementing dryland farming tech-niques,and promoting an allround development of agriculture, forestry, and animalhusbandry as well as the diversified economy. Research on dryland farming techniquesin North China centers on farming tillage system with priority given to water storageand moisture preservation, improvement of water use efficiency, soil betterment andfertilizer application techniques and management of soil and crop moisture. According-ly, the important progress has been made in agricultrual water-saving techniques, cropdrought-resistance physiology and selection of drought resistant crop varieties, compre-hensive control over the arid areas, and technical package of yield increase in dryland. This paper also suggests that it be important to sum up experience, to speed up the con-version of research achievements, and to advance the new,allround and directional bal-ance of dynamic moisture in drylands of different types in the arid area, the dynamiclaws of water-soil-light-heat-atmosphere-plant agroecosystem and its adjustment andcontrol, the laws of water requirements of main crops,the technical package of improv-ing rainfall water and water resource productivity,the optimal combinations of land useand water and soil conservation practices,the principles and methods of drought resis-tance of main farm crops,the development of drought resistance crop varieties, the es-tablishment of sustained farming and agronomy system and the inner good cycle mecha-nisms of agroeco-economic system,drought resistant countermeasures in the arid areasso as to form the complete dryland farming research system. These are the importantmeasures to guide the dryland farming research in depth North China.