Study On Evaluation Index System Construction And Application Of Chemical Fertilizer Reduction And Benefit Improvement Technology Models Of Protected Vegetables In Cold Region Of Liaoning Province

With the development of society and the advancement of science and technology,protected agriculture is booming.Among them,protected vegetables are an important part of protected agriculture.Its planting area and production output are increasing year by year,which greatly meets people's demand for fresh vegetables and improves income to farmers.However,a series of problems have also been exposed in the process of vigorous development.The excessive use of fertilizers and pesticides is especially prominent,not only causing the waste of resources,also causing soil acidification,which is not conducive to the sustainable development of the protected vegetable industry.In order to solve these problems,the technology of reducing fertilization application and increasing its efficiency in protected vegetable has been vigorously promoted and applied,but local farmers have low responsiveness to those promoted technologies with poor sustainability during the extension based on our field investigation.In order to improve the level of agricultural technology popularization and ensure the sustainability of protected vegetable cultivation,it is necessary to build a comprehensive and systematic technical evaluation index system and apply a scientific and reasonable comprehensive evaluation model to carry out scientific evaluation during technology popularization and application.In this paper,by using the methods of literature analysis,the expert consultation and the expert constrained principal component weighting,a set of evaluation index system for the chemical fertilizer reduction and efficiency improvement technologies consisting of the criteria,the indicators and the sub-indicators three layers with a total of 27 indicators was constructed.Both the expert component-based principal component analysis model and the gray correlation analysis model were employed to evaluate the social and economic effect of five different chemical fertilizer reduction and benefit improvement technologies modes in Liaoning Province.The weights of each indicator were calculated,and then the comprehensive scores and rankings of five technical modes were obtained with the weights and indicator data.The results of the two evaluation models are consistent with the optimal three technical modes.The rankings followed the order of summer tomato fertilizer reduction technology mode in the city of Beipiao > winter and spring tomato fertilizer reduction technology mode in the Liaozhong district > winter tomato fertilizer reduction technology mode in the city of Dengta.The evaluation results can provide a reference for the promotion and application of integrated technology modes for reducing vegetable fertilizer application and increasing efficiency in protected vegetable industry in Liaoning Province and other cold regions.In particular,it will help the agricultural technology extension sector to carry out the promotion of different technology modes.According to the results of comprehensive evaluation,the summer tomato mode of chemical fertilizer reduction and benefit improvement is better than the other four modes,and it is worth popularizing in cold area.However,from the four aspects of technical characteristics,economic benefits,social benefits and management respectively,each of the five technical modes has its own advantages and disadvantages.It is suggested that the integration of technology modes with lowerranking of technical characteristics and economic benefits be further optimized and improved,for example,shortening the growing period,controlling the input of materials and raising the level of mechanization and reducing the labor cost,so as to increase the net income of vegetable planting.It is also suggested that for technology modes with low social and managerial scores,local governments need to continue to improve the matching policies of extension technology,such as strengthening the media's publicity and increasing the frequency of rural training and guidance for agricultural technicians going to rural area.Efforts should be made to combine enterprises,universities and research institution so that vegetable farmers will feel the broad prospect of scientific planting of protected vegetables and the great potential for increasing income,in the meantime,more farmers will understand and accept chemical fertilizer reduction and benefit improvement technology modes.