Study On Characteristics Of Nitrogen And Phosphorus Nutrient Flow In Food Chain In Northeast China

With the rapid development of economy,a constant improvement in diet structure among the citizens,the nutrient flows change constantly as well,and this change causes increasing environmental pressure,so the nutrient management issue is further researched.The Northeast China is an essential place where the commodity grains and livestock products are produced.The mass production of livestock products influences the nutrient flows,however,there are some differences among different places.Therefore,the nutrient flow characteristics of cropping-livestock system are urgently needed to be resolved,and its problems are revealed.And to the different nutrient flow characteristics,the reasonable optimization strategies are proposed,and further make efficient utilization of the Nitrogen and Phosphorus nutrients in Northeast China Region,and facilitate the sustainable development for agricultural industry as well.By the method of statistics,databases and the NUFER(Nutrient Flows in Food Chain,Environment and Resource use,NUFER),this research investigates the Nitrogen and Phosphorus nutrient flows and characteristics in Food Chain from 1984 to 2004,and offer theoretical basis for the Nitrogen and Phosphorus nutrients management in Northeast China Region.The results are shown below:(1)In Northeast China,the total inputs of food chain system increased dramatically,from1984 to 2014,The proportion of feed input was increased in Liaoning area.And the total inputs of the Nitrogen and Phosphorus nutrients was 2131 Gg and 512 Gg in1984,up to 5726 Gg and1632 Gg respectively in 2014.The rate of increase was 1.7 and 2.2.In 2014,the input of nitrogen and phosphorus nutrients in Northeast China were as follows: Heilongjiang > Jilin >Liaoning.The input of nutrients mainly comes from the chemical fertilizer and the external input of fodder.In terms of fertilizer application,the proportion of nitrogen and phosphorus was the fastest rising in the Jilin region from 54% and 79% up to 72% and 86%,respectively.The external input of fodder,the proportion of feed nitrogen and phosphorus nutrients increased significantly in Liaoning region,from 3% and 7% to 23% and 32%,respectively.(2)In the past 30 years,the total sales volume of nitrogen and phosphorus in agricultural and livestock products in Northeast China increased gradually.Among them,the highest nutrient production of agricultural and livestock products in Heilongjiang region,it's export volume is also first in Northeast China.In the nutrient output,part of the nutrients are discharged into theatmosphere and water bodies in a loss way.Nitrogen was mainly dominated by ammonia volatilization,and the total ammonia volatilization was 1450 Gg in 2014;Phosphorus was through leaching,runoff and erosion of the path loss,and the amount was 20 Gg.The loss rate of nutrients is increasing in Northeast China.Among them,the loss rate of nitrogen nutrition in Jilin area was the highest,and the loss rate was 47% in 2014.The phosphorus loss rate was highest in Liaoning area,and the phosphorus loss rate was 23% in 2014.In the past 30 years,about 50% of the total nitrogen has been accumulated in the form of waste,the quality of phosphorus is about 80% accumulated in the form of waste in Northeast China.The accumulation of nitrogen and phosphorus in Heilongjiang area was significantly higher than that in other regions.(3)In the nitrogen and phosphorus nutrient recycling,The amount of nitrogen and phosphorus was increased from 345 Gg and 103 Gg in 1984 to 874 Gg and 258 Gg in 2014,Increased by 153% and 150%,respectively.In the past 30 years,the efficiency of nitrogen and phosphorus was decreased.The results between the different provinces show that the highest recycling rate was Jilin region and the lowest recycling rate in Liaoning region.(4)From 1984 to 2014,the nitrogen nutrient in farmland production system in Jilin,Liaoning and Heilongjiang region decreased by 10%,11%,and 32%,respectively;Phosphorus nutrient use efficiency decreased by 16%,2%,and 23%,respectively.In livestock production system,the utilization of nitrogen nutrient increased by 3,11,and 10 percentage points respectively,and the phosphorus content increased by 0.8,1.9,and 3.2 percentage points,respectively.The agriculture and animal husbandry production system of nitrogen use efficiency from 26%,36% and 52% in 1984 fell to 13%,21% and 22% in 2014,the overall performance was: Heilongjiang > Liaoning > Jilin;the nitrogen use efficiency from 25%,25% and 31% in1984 fell to 9%,14% and 10% in 2014,the results were as follows: Liaoning > Heilongjiang >Jilin.In conclusion,nearly 30 years,the input Nitrogen and Phosphorus nutrient has increased significantly in Northeast China Region.Different provinces show quite different results,and according to the nutrient flows and characteristics in different regions.We puts forward some reasonable suggestions.In a word,as for the nutrient management of cropping-livestock system in Jilin region,nutrients should be optimally used in land production,Nitrogen and Phosphorus nutrient input rationally,and the nutrients should be reused.In Liaoning region the nutrient management should be paid attention to livestock production,and the reasonable programming of crop-livestock integration should be put forward,take advantage of the crop straws as fodder,and reduce the nutrient losses.In Heilongjiang region,the rational inputs of fertilizer should bedrawn attention,meanwhile economize the abundant land resources,further strengthen crop-livestock integration,reduce losses,and improve the recycling utilization.At the same time,in Northeast China Region,speeding up structural adjustment,the intensive management crop-livestock integration system should be thorough.Strengthening the nutrient coordinated management,learning mutually,noticing agricultural resource allocation,and nutrient flows in food chain in Northeast China Region should be facilitated.