Characteristic of non-point source biochemical oxygen demand from agricultural land in the part of Code River

Non-point source (NPS) is one of the global issues dealing with water quality. This pollutant source contributes a lot to pollution and it is relatively hard to control. Agricultural land is one kind of NPS. Cultivation activities that aim to prepare land for the crop planting could increase the potency of pollution load. It is important to know the characteristic of pollution load in agricultural land. The amount of pollution load in agricultural land tends to be fluctuating. The objective of this study is to know the characteristic of pollution load in agricultural land. The method used in this research is the statistic test. Scatterplot as a data presentation technique. The independent variable used in the statistic test is the interval between the last rain and the time of sampling (X₁), the thickness of the rain (X₂), and the discharge (X3). Test F shows that the independent variable gives simultaneous influence to the concentration of BOD in agricultural land. Test T shows that the influences every independent variable to the concentration of BOD. The relation between the concentration of BOD (Y) and the independent variable is formulated as follow: Y = 0,810 - 0,160 X₁ - 0,490 X₂ + 21,704 X₃. Pollution load of NPS is temporally fluctuating. The maximum pollution load from agricultural land happens when the rainfalls. In normal condition, the pollution load is minimum.