Study On The Prevention And Control Of Agricultural Non-point Source Pollution

With the rapid development of the national economy,the problem of pollution from point sources such as urban living pollution and industrial pollution that has been plagued by the past has made greater breakthroughs.With the transformation of agricultural production methods,intensive agricultural production has developed rapidly and agricultural pollution has become increasingly prominent.Agricultural non-point source pollution has become an important issue in current environmental protection work.The complex and extensive nature of agricultural non-point source pollution determines that it is impossible to effectively control the pollution by simply relying on the end of the pollution.Through reasonable planning and source reduction,it will be an important means for prevention and control of agricultural non-point source pollution.This study takes the agricultural non-point source pollution prevention planning method as the research object,through the construction of the regional agricultural non-point source pollution status assessment model,the research on the accounting method of regional livestock and poultry breeding carrying capacity based on the balance of planting and breeding,and the zoning and classification of agricultural non-point source pollution prevention and control.The research on prevention and control technologies and measures explored ways to effectively implement regional agricultural non-point source pollution prevention and control planning.Taking the Lingshui Li Autonomous County of Hainan Province as an example,an empirical study was conducted on the method of formation.The following conclusions have been formed.1)Through a large number of literature review,we understand the current agricultural non-point source pollution analysis model types,and compare the advantages and disadvantages and applicability,and choose the analytic hierarchy process as the analysis model.Through the yearbook data review and field research,sum up the summary data,select representative and scientific indicators as evaluation indicators,determine the evaluation indicators and index weights,and build an agricultural non-point source pollution analysis model.2)A more complete accounting method for bearing capacity of livestock and poultry was constructed through literature search,comparative analysis and other methods.The specific calculation method is as follows:C_N=(??1+??T_NZ)/???1-?????In the formula,CN is the carrying capacity of livestock and poultry in the region;TNZ is the amount of nitrogen provided by the outside world for the crop;?is the nutrient?nitrogen and phosphorus?provided by the organic fertilizer of the livestock manure and accounts for the nutrients in the whole process of growth and development of crops and vegetables?The ratio of total nitrogen and phosphorus consumption,?is the correction factor for nitrogen nutrient consumption of crops,vegetables,etc.due to droughts and floods,natural disasters,diseases and insect pests,improper field management,etc.,resulting in distortion of economic yield;The effective collection rate of poultry manure is 80%;?is the loss rate of nitrogen nutrient in the form of ammonia in the process of collection,storage,transportation and application of manure organic fertilizer.The loss rate is 30%;?is the livestock manure nitrogen standard equivalent?this plan Live pigs are equivalent livestock,so the value is 3.78?;?organic fertilizer utilization efficiency?nitrogen is 45%?.An early warning system for livestock and poultry breeding environment was constructed,and the load warning value?was proposed.A five-level classification standard for farmland livestock and poultry load warning was used to assess the extent of regional pollution.3?The definition of agricultural non-point source pollution control zoning is based on the comprehensive evaluation of regional agricultural non-point source pollution?this paper considers the crop planting pollution,livestock and poultry breeding pollution,aquaculture pollution,rural living environment pollution?to determine the comprehensive pollution degree of agricultural non-point source and agricultural surface source The degree of contamination of pollution types forms the standard for the control of agricultural non-point source pollution in the region.4)Taking the prevention and control of agricultural non-point source pollution in Lingshui,Hainan Province,as an example,the method of formation was empirically applied.Through the evaluation results of agricultural non-point source pollution in Lingshui Lizu Autonomous County,it can be known that the average comprehensive score of agricultural non-point source environment in the county was 0.439.The overall situation is better.According to the calculation of the bearing capacity model,when the total nitrogen required by crops in the Lingshui Li Autonomous County of Hainan was provided by livestock and poultry,the maximum carrying capacity was 3,569,992.Through constructing an early warning system for livestock and poultry breeding environment,and calculating and analyzing,the critical livestock and poultry breeding volume in the Lingshui Li Autonomous County of Hainan as a standard equivalent is 1,606,496.Based on the comprehensive evaluation results of agricultural non-point source environment and the types of agricultural non-point source pollution,the first-level and second-level zoning control of hierarchical management and classification control in Lingshui Li Autonomous County was realized.