Evaluation of Management Practices on Crop Yield and Nutrient loads in a semi-arid tropical watershed using a process based Hydrologic Model.

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Pesapati Gautham, K.B.V.N. Phanindra

Thursday 2 july 2015

9:30 - 9:45h at Central America (level 0)

Themes: (T) Water resources and hydro informatics (WRHI), (ST) Catchment hydrology

Parallel session: 10H. Water resources - Catchment

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Effective management of irrigation water requires a prior knowledge of crop water requirement. This study aims at understanding water-plant-yield relations at sub-catchment scale, by analyzing crop water productivity (CWP) considering various management scenarios. A pre-calibrated (for catchment outflows and nitrate loads) hydrologic model of the Singur-Manjeera Basin in Telangana, India was considered in the present study. Process based hydrologic model, SWAT was used to simulate crop yield and groundwater depths on daily time step for the irrigation years 2013-15. Data on meteorological, soil, land-use, crop, irrigation, and management practices was provided using geographical interface ArcSWAT. A total of 584 hydrological response units (HRUs), 20 sub basins, and 20 reaches were delineated. Model calibration (for crop yield and groundwater depth) was performed at sub-basin level specific to each crop class using SUFI-2 algorithm in SWATCUP. The calibrated model was further applied to evaluate the impact of various conservation practices by considering changes in land use, copping pattern, climate, and fertilizer application. Statistical analysis was performed to rank the management practices (specific to the region) considering higher CWP and lower groundwater nitrate loads. Keywords:Best Management Practices (BMP), crop yield, SWAT, Singur-Manjeera Basin, groundwater