NITROGEN FLOW ANALYSIS FROM DIFFERENT LAND-USE OF THE CHI RIVER BASIN (MAHA SARAKHAM REGION, THAILAND)

Abstract

This paper aims at assessing the effect of land use on nitrogen flows from a significant landuse area in the Chi River basin (Maha Sarakham region) in Thailand. The Chi River is one of the main rivers,
and many land use categories affect the quality of the river. Statistical data and referred data was collected as
the secondary data from credible sources to identify the flows. The data show a strong effect of land use on
nitrogen with the highest load dominated by paddy field (66,597.51 tonne/year), and the lowest value in the
community (1,005.71 tonne/year). Nitrogen flow increased with the fertilizer application in paddy field and
farm plants (34,834.07 tonne/year). Paddy field discharged nitrogen to the Chi River 47 tonne/year in form of
surface runoff. Also, the community without wastewater collection system takes part in a non-point source
(NPS) of nitrogen to the Chi River at 299 tonne/year. The management's suggestion is to control fertilizer
application, burning of agricultural residue such as rice straw, and wastewater treatment before disposal.