MODELLING OF EVAPOTRANSPIRATION AND DETERMINATION OF WATER REQUIREMENT FOR TOMATO CROP USING WEIGHING TYPE LYSIMETER UNDER AGRO CLIMATIC CONDITIONS Of RAICHUR KARNATAKA

Abstract

newline Globally, water is considered as a precious element for the agricultural sector. Water newlinebeing a scarce resource, it is necessary to use judiciously and manage this natural resource newlinescientifically to sustain life on earth. Irrigation is the major consumer of water in the country newlineand therefore water used for irrigation must be prudently managed to ensure high efficiency. newlineOne of the most important factors for water resources planning and irrigation scheduling is newlinecrop evapotranspiration (ETc) or crop water use. The low cost weighing type lysimeter was newlinedeveloped and installed at experimental plots of Soil and Water Engineering, CAE, Raichur, newlinefor evapotranspiration studies. The various empirical models (Blaney Criddle, Hargreaves, newlineChristiansen, Turc, Modified Penman, Open Pan and Penman Monteith) were studied and newlinesoft computing models like ANN and fuzzy logic models were developed with the selected newlineinput parameters. For the proposed study, the daily data of various weather parameters viz., newlinemaximum and minimum air temperature, maximum and minimum relative humidity, wind newlinespeed, actual sunshine hours and rainfall for the duration of 31 years (1991-2021) of Main newlineAgricultural Research Station (MARS), Raichur were used. Through suitable statistical newlineanalyzers, when potential evapotranspiration rates were compared with standard penman newlineMonteith model, the following close rank of the performance was observed: Open Pan, newlineChristiansen, Turc model, Blaney Criddle, Hargreaves and Modified Penman models, newlinerespectively. Similarly, based on correlation and statistical parameters, the ANN models of newlinefeed forward neural network with Levenberg Marquardt model (FNN-LM) was considered as newlinebest fit model for Raichur region. The tomato crop was selected and field experiments were newlineconducted in weighing lysimeter for three seasons rabi - ( during 7 newlineth September 2021 to 5th newlineJanuary 2022); Summer - (during 15th January 2022 to 15th May 2022) and Kharif - (during newline6 newlineth June 2022 to 4th October 2022). The crop coefficients (Kc) were high d