Input-Output Model of Nitrogen at the Rembangan River Caused by Fertilization on Coffee Plantations

Abstract

In general, agricultural wastes that pollute rivers are liquid wastes that come from the activity of plant fertilization. This waste is a type of non-point source of waste. One of macro elements contained in the fertilizer is Nitrogen. To keep the quality of water remain on the condition that is in accordance with its allocation will require efforts to manage river water quality and monitoring, one of them is by using water quality modeling of mass balance model of pollutant loads in river. The basic concept of this mass balance model is a calculation of how much load of fertilizer (N element) on the plant, how much load is going into the river as the load of pollutants in the river through surface runoff as well as how much load is dropped in river as a load of pollutant resulting from the fertilization events? The objectives of this research are to identify characteristics of types of pollutants in the area of coffee plantations, the pattern of spatial distribution of pollutants in the river, to identify the relationship between changes in load Dissolved Oxygen (DO) of river water and the addition of nitrogen pollutant load in the area of coffee plantations and to find out the load of pollutants entering the rivers. This research was initiated with the river and soil water sampling in plantation areas which were then tested for the concentration of nitrogen in the form of ammonium and nitrate, and were further analyzed with regression and correlation methods. Results of primary and secondary data analysis would be used as a basis for preparing a mass balance model of river pollutant load. The results of this research were that the correlation between DO concentration changes and the addition of nitrate showed conflicting relationships, as indicated by the regression equation for the events of time before fertilization: y = 80.89586 -1.80801 x the closeness of the relationship of r = -0.837. Meanwhile, for the time after fertilization, it was indicated by the regression equation: y = 80.89586-1.80801 x the closeness of the relationship of r = -0.977. Input-output model of nitrogen in Rembangan river which is a tributary of Bedadung river that flows and divides coffee plantations Renteng Afdeling Rayap Jember was able to show the decrease of nitrate load in the river, so that this could provide information that the activities in coffee plantation of Rayap Jember both before and after fertilization had not caused a significant increase in nitrate concentration, which means that it did not cause pollution of water of Rembangan river.