Research On The Environmental Pressure And Strategy Of Rice Production In Heilongjiang Province Based On The Carbon Footprint And The Grey Water Footprint

Agricultural production is one of the main sources of greenhouse gases(GHGs)emissions in climate change,and crop production is an essential part of agricultural production.In order to increase grain production,excessive input of agricultural products such as chemical fertilizers and pesticides will inevitably occur during the production process,which will lead to water pollution and negative impact on the environment.Heilongjiang Province is the largest and most important japonica rice production area in the world.This paper analyzes the changing tendency and influencing factors of carbon footprint and grey water footprint in rice production over the years,and studies its relationship with yield per unit area of rice.This paper has certain significance for reducing environmental pressure and realizing sustainable development of rice production in Heilongjiang Province.Firstly,the carbon footprint of rice production is analyzed.Based on the Life Cycle Assessment theory(LCA),the carbon footprint,carbon cost and carbon efficiency of rice production in Heilongjiang Province in the past 15 years are calculated and analyzed.The time series characteristics of rice production carbon footprint during 2002-2006,2007-2011,2012-2016 are analyzed.And Spearman correlation test and regression equation theory are used to analyze the influencing factors of carbon footprint method in rice production.The conclusion is that the average carbon footprint per unit area of rice production in Heilongjiang Province is 1721.42±256.53kgCE/hm2,which is generally declining and the fluctuation range is small.The carbon footprint value of rice production in Heilongjiang Province decreased in recent years,but the fluctuation range increased.The use of irrigation electricity has the greatest impact on the carbon footprint of rice production.Secondly,the grey water footprint of rice production is analyzed.This paper compares and analyzes the yield per unit area of rice production and the input of chemical fertilizer in Heilongjiang Province over the years.Based on the calculation method of grey water footprint,the grey water footprint value of rice production in Heilongjiang Province in the past 15 years is calculated,and the time series characteristics of grey water footprint of rice production in three time periods are analyzed.And Spearman correlation test and regression equation theory are used to analyze the influencing factors of grey water footprint in rice production.The conclusion is that the average gray water footprint of rice production in Heilongjiang Province in the past 15 years is 192.69±38.99m3/t,and the grey water footprint of rice production shows a downward trend.The average value of grey water footprint during three periods in Heilongjiang Province decreased gradually,and the fluctuation range also decreased gradually.During the period of 2005-2016,the grey water footprint of rice nitrogen fertilizer production showed a downward trend,and the use of nitrogen fertilizer was significantly correlated with the grey water footprint of rice production.Finally,based on the time series data of carbon footprint per unit area and yield per unit area of rice production in Heilongjiang Province from 2002 to 2016,the possible cointegration relationship between crop yield and environmental pollution was analyzed by using the improved EKC model and introducing quadratic parameters.On this basis,the Grainger causality between the two variables are tested.The results showed that there was a long-term and stable cointegration relationship between carbon footprint per unit area of rice production and yield per unit area in Heilongjiang Province,and the relationship between carbon footprint and yield per unit area showed a ’wave’ curve shape.Furthermore,the study shows that there is a one-way causal relationship between rice yield per unit area and carbon footprint per unit area in Heilongjiang Province.The change of rice yield will lead to the change of carbon footprint,but the change of carbon footprint will not cause the change of rice yield.The correlation between gray water footprint and yield per unit area of rice production in Heilongjiang Province is analyzed,and it is found that there is a significant negative correlation between them.Therefore,the environmental pressure of rice production in Heilongjiang Province can be reduced by reducing power consumption,rationally improving the utilization rate of chemical fertilizer,rationally reusing agricultural film,optimizing the proportion of chemical fertilizer application,and building high-standard farmland.