Study On Regulation Model And Method For "Water-Land-Forage-Livestock" Balance In Pastoral Area

In China most pastoral areas are located in arid and semi-arid with water scarcity and unmatched water and land resources,and imbalance grass and livestock condition.In consequence grassland degradation and serious desertification have been induced.The main factors for ecological system degradation in pastoral areas were overgrazing and agricultural development.With progress the research for alleviating ecological degradation in pastoral areas is evolved gradually from achieving the balance between forage and livestock to achieving the balance among water,land,forage,and livestock.In this study the analysis is based on the carrying capacity of water and land resources by coupling the natural grassland and artificial grassland.The structure of grain crops,economic crops and forage crops is optimized to develop suitable irrigated artificial grassland,and reasonably determine the suitable livestock breeding scale with constraint of realizing the dynamic balance among water,land,forage and livestock,so as to gradually restore a favorable ecological system and its environment and maintain sustainable development of society and economy.In this study,the regulation theory for the balance among water,land,forage and livestock balance was developed and the regulation model is established for the pastoral area.With Etuokeqian banner as pilot pastoral areas,the model was used to study the relationship between development of water and land resources and its response in economic benefit and ecological system comprehensively under different schemes.The threshold of "water-land-forage-livestock" control was given.Based on the research results of pilot pastoral areas,the paper analyzes the scale and expected benefit of agriculture and animal husbandry in the pastoral areas.The main progress and conclusions are as followings:1.The balanced regulation mechanism among water.Land,pasture and livestock was explored and elaborated.Base on grassland ecosystem service value theory,grassland ecosystem grazing disturbance theory,natural grassland and artificial grassland coupling theory and water,land and grassland resources optimal allocation theory,the threshold of "water-land-forage-livestock" control was proposed and the regulation theory for the balance development of water,land,forage and livestock was developed.2.Based on the established regulation theory,this paper proposes"water-land-forage-livestock " balance regulation technical framework.The"water-land-forage-livestock" balance regulation model is constructed with ecological benefit and economic benefit,coupling with groundwater equilibrium model for the dynamic calculation of exploitable quantity of groundwater.On this basis,the calculation program is developed as an analysis tools for the quantitative study of the"water-land-forage-livestock" balance regulation threshold.3.Based on the application of "water-land-forage-livestock" balance regulation model in pilot area of Etuokeqian banner,the following conclusions are proposed:a.The results showed that the total efficiency of the system is varied from 2020 to 2030 with first increase and then decrease process.With the increase of livestock feeding time,the area of irrigated artificial grassland is increased,and the regional development was gradually limited by grassland resources due to water resources constraints.The study area is rich in land resource,water resources are the key limitation factor to control the regional "water-land-forage-livestock" balanced development.b.According to the calculation results of water supply and exploitable quantity of groundwater,the amount of water used for scenario 1 to 9 will increase from 130 million m~3 to 166 million m~3 in 2020,from 204 millionm~3 to 266 million m~3 in 2030.The exploitation quantity of groundwater is not affected by the change of water use pattern.With the implementation of water saving irrigation scheme and the adjustment of water structure of industrial and agricultural,the annual recharge of groundwater in the planning year shows a slight decrease trend.c.According to the comparison and analysis of scenarios,the suitable control level of livestock in Etuokeqian banner in 2020 should be feeding 6 months plus supplementary feeding 2 months rather than 6 feeding months.The development scale of water resources,land resource and irrigated artificial grassland should be controlled in 166 million m~3,32930 to 33990 hm~2 and 21570 to 25380 hm~2,respectively.Irrigated artificial grassland should account for 2.78?3.27%of natural grassland,and livestock should be controlled within 0.89 to 1.0 million sheep units.In 2030 the control level of livestock in the barn should be shifted from feeding 6 months plus supplementary feeding 2 months to feeding 8 months.Water resources,land resource and irrigated artificial grassland development scale should be controlled at 266 million m~3,42450 to 43120 hm~2 and 30360 to 34210 hm~2,respectively.Irrigated artificial grassland should account for 3.91 to 4.32%of natural grassland,and livestock keeping should be controlled in 1.14?1.19 million sheep units.4.According to the application of the model in pilot pastoral areas and other related research results,this paper analyzes the suitable scale and expected benefit of agriculture and animal husbandry in the pastoral areas of whole China,and the following conclusions are proposed:a.According to the carrying capacity of water,land and grass resources in China's pastoral areas,the appropriate irrigation area for crops and pastures was 8.43 million hm~2 and 9.36 million hm~2 in 2020 and 2030,respectively,and the irrigated artificial grassland should be 1.56 million hm~2 and 2.00 million hm~2 in 2020 and 2030 respectively,and suitable amount of livestock should be 264 million sheep units and 288 million sheep units respectively.b.The development priority of irrigated artificial grassland is to equip the existing irrigated artificial grassland with water saving technology 2020.By 2030,119900 hm~2 of irrigated artificial grassland will be increased.About 1.05 million hm~2 irrigated artificial grassland will be developed.