Emergy Analysis Of Agricultural System In The Loess Plateau

The Loess Plateau is a famous ecological fragile area and the main places for human agricultural activities since ancient times.The ecological environment and the level of the agricultural production in the Loess Plateau have been improved through the implementation of a series of ecological restoration such as returning farmland to forests,but the agricultural structure in the Loess Plateau is still unreasonable.In this paper,the sustainability of characteristic agricultural production system in the Loess Plateau were analyzed by the emergy method and China soil erosion equation(CSLE),based on this,the ecological-economic benefit coordination area of various agricultural products is analyzed through the coupling coordination degree model.The objective is to provide a theoretical basis for the adjustment and sustainable development of agricultural industry structure in the Loess Plateau.The results show that:(1)The land use types of the Loess Plateau in 1995 and 2000 were mainly sloping farmland and grassland.The vegetation coverage was low,which easily caused soil erosion and soil erosion.Since the implementation of a series of ecological restoration in 1999,a large area of arable land has been transformed into forests and grasslands,which has increased the vegetation coverage of the Loess Plateau,thereby effectively improving soil erosion and reducing the intensity of soil erosion.The soil erosion modulus in the Loess Plateau area decreased from 2,593 t/(km2·a)in 1995 to 1,069 t/(km2·a)in 2018,a decrease of 58.8%,and the intensity of soil erosion changed from moderate erosion to that slight erosion.The soil erosion has been significantly improved.(2)The proportion of production in the Loess Plateau decreased from 64.9%to 44.3%,breeding increased from 26.0%to 39.6%,and apple increased from 9.0%to 16.1%from 1995 to 2018,which indicating that as ecological restoration proceeds,cultivated land has been transformed for forest and grassland,the scale of planting has decreased.At the same time,with the improvement of living standards,people’s demand for meat,eggs,milk and other products is increasing,and the scale of breeding industry has increased significantly.(3)From 1995 to 2018,the ESI values of the aquaculture and apple industries in the area increased year by year,reaching the maximum values of 1.952 and 1.219 respectively in 2018.This is because the growth of ELR(56.6%of the aquaculture and 9.5%of the apple industry)is less than that of EYR.(146.6%in the aquaculture industry and 230.7%in the apple industry),the system ESI shows an increasing trend,the sustainability and development potential of the aquaculture system in the Loess Plateau is better than Planting industry and apple industry.With the ecological restoration,the soil erosion situation has slightly improved,and the sustainability of the agricultural ecosystem is also showing a trend of improvement.However,although the agricultural ecology of this area is currently in a slightly sustainable state,its sustainability is still low.Therefore,the research area should rationally adjust the energy input structure,develop the agricultural industry according to local conditions,and pay equal attention to development and protection,to improve the sustainability of the system.(4)The economic-ecological benefit coordination performance of each industry from 1995 to 2018 is as follows:wheat,corn,and milk are basically coordinated,pork and beef improved from moderate imbalance to basic Coordination,vegetables decreased from moderate coordination to basic coordination,mutton decreased from basic coordination to moderate imbalance,oilseeds and apples are moderately imbalanced.In 2018,the average coordination degree of each city was 0.452,0.508,0.545,0.539,0.467,0.532,0.317,0.287 and 0.395,respectively.(5)Based on the emergy perspective,through the coupling and coordination model,the regions that are relatively suitable for the development of various industries in the study area are as follows:1)Wheat:Linfen,Yuncheng,Baoji,Xianyang,Weinan,etc.2)Corn:Xinzhou,Ordos,Bayannaoer,etc.3)Vegetables:Xianyang,Yuncheng,Guyuan,etc.4)Oil:Bayannaoer,Ordos,Hohhot,etc.5)Pork:Yuncheng,Linfen,Jincheng,Changzhi,Jinzhong,etc.6)Beef:Guyuan,Pingliang,Ordos,Jinzhong,etc.7)Lamb:Ordos,Bayannaoer,Baotou,Yan’an,Yulin,etc.8)Milk:Hohhot,Ordos,Bayannaoer,Baotou,etc.9)Apple:Linfen,Yuncheng,Xianyang,Pingliang,Yan’an,etc.