Evaluation On The Benefit Of Technologies For Reducing Fertilizers And Pesticides In Wheat And The Efficiency Of Powdery Mildew Prediction Models

For a long time,the excessive use of fertilizers and pesticides had caused the environmental pollution and ecological damage,which created a great impact on the sustainable development of wheat production in China.In recent years,China has implemented some policies and established a series of integrated technologies for reducing fertilizers and pesticides to achieve the coordinated development of wheat production and ecological protection.The evaluation is particularly important to the promotion and application for the integrated technologies.The comprehensive benefit evaluation system of the integrated technologies of reducing fertilizers and pesticides in wheat was established in this study,and some integrated technologies in Yangtze River Basin and Northern wheat regions were evaluated by this index system,this can provide a basis for the application and promotion of these integrated technologies in production.The accurate prediction models of wheat diseases are one of the key technologies for precise disease prevention and control.It can realize the scientific prevent,control of plant diseases and reduce the pesticides application,sequentially improve the comprehensive benefits of wheat production.On the basis of previous studies,and in order to further improve the accuracy of wheat powdery mildew prediction models,this study collected the published wheat powdery mildew prediction models in China,and analyzed the practicality,timeliness,accuracy of these models.Some of these models were simplified and optimized or rebuilt,which provided a basis for the application of these models in production.The main conclusions are as follows:(1)Investigation and evaluation indicies of reducing fertilizers and pesticides in wheat,according to the principles of constructing the evaluation index system and the basis of selecting evaluation indicies,combined with the needs of the integrated technologies of reducing fertilizers and pesticides in wheat,indicators which include 1 target(benefit evaluation of the technologies for reducing fertilizers and pesticides in wheat),3 categories(economic,ecological and social benefit),11 indicators were established,and the weight of indices were determined.The index system as follows: economic benefit indicators include: net income per unit,per capita net income,input-output ratio and indirect economic benefits,their combined weights are 0.23,0.18,0.12 and 0.04 respectively;ecological benefit indicators include: the unit profit consumes chemical fertilizers,the unit profit consumes pesticides,the amount of organic fertilizers per mu and the use of resistant varieties,their combined weights are 0.13,0.11,0.04 and 0.02 respectively;socia benefit indicators include: wheat yield per mu,labor capacity and psychological endurance effect,their combined weights are 0.08,0.03 and 0.02 respectively.Use the constructed evaluation system to evaluate the benefits of some integrated technologies in the Yangtze River Basin and Northern wheat areas,the results shows: The benefits of integrated technologies in the Yangtze River Basin wheat regions were at least 25% higher than conventional fertilizers and pesticides application regions,among them,Qujing in Yunnan province increased by 10 times.The benefits of some integrated technologies for reducing fertilizers and pesticides is improved compared to technologies for conventional fertilizers and pesticides on wheat powdery mildew field trials at Northern wheat regions in Langfang,among them,the benefit(normal fertilizers,reducing pesticides by 11%),(normal fertilizers,reducing pesticides by 33%)and(reducing fertilizers by 28% and pesticides by 11%)is higher under the same wheat variety,chemical fertilizers and pesticides,which is 406.67%,300% and 300% higher than the conventional fertilizers and pesticides technology.(2)Totally 46 models from 31 cities(counties)of 9 provinces(autonomous region,municipality)in China were collected.Based on their practicality,timeliness and accuracy,six models were chosen and further simplified,optimized or rebuilt,total 12 prediction models were obtained for 7 cities of 4 provinces.Accuracy test of these models,the results shows: For the ratio fitting of the historical data,the optimized models of Gaoyou in Jiangsu province and Bazhong in Sichuan province improved by 3.09% and 38.28% respectively compared with the original models;the two optimized models in each city of Nanchong in Sichuan province and Anyang in Henan province were improved by 115.77% and 132.20%,25.77% and 18.82% respectively compared with the original models;the two simplified models in Zhangqiu in Shandong province are improved by 45.82% and 43.51% respectively compared with the original model.For the ratio fitting of the current data,the two optimized models in each city of Nanchong in Sichuan province and Anyang in Henan province were improved by 111.47% and 103.23%,41,57% and 10.95% respectively compared with the original models,the two simplified models in Zhangqiu in Shandong province are improved by 46.44% and 47.86% respectively compared with the original model.