Development of a new model for health assessment in agroecosystems.

Abstract

Healthy agroecosystems provide a range of ecosystem services, and the lack of information about the importance of their health degree leads to the unsustainability of these agroecosystems. To assess the health status of agroecosystems, a model was developed using spatial analysis-based procedures in Geographic Information System (GIS) media, surveyed data, and field monitoring at Gorgan University of Agricultural Sciences and Natural Resources. Initially, a survey-based study was conducted in 50 barley fields of Bandar-e-Torkaman County, north of Iran, during the 2016-2017years. Then, the health index maps were provided by spatial analysis-based functions in GIS media. For accurate estimation of health status in barley agroecosystems, some meteorological variables were layered. Finally, the health status of the agroecosystems was determined based on six indices, including pesticides consumption rate, chemical fertilizers consumption rate, crop yield, and cultivar type, soil organic matter, and biodiversity indices. When all the layers overlaid, only 12% of the surveyed agroecosystems were located in the healthy class. The use of proper tillage methods, the appropriate weed control operations, the optimum consumption of high-quality pesticides, high soil organic matter, and grain yield > 2.6 ton ha-1 were the main reasons for obtaining of health degree in these agroecosystems. In contrast, the consumption of low-quality pesticides, the use of inappropriate tillage tools and machinery, the little knowledge of the farmers about the optimum rates and consumption methods of pesticides and chemical fertilizers, and resistance of some weeds to herbicides were identified as the most essential reasons for non-health status in the most surveyed barley agroecosystems.