Estimation of Crop Evapotranspiration for Groundnut Crop in Semiarid Region of Maharashtra, India

Abstract

Efficient irrigation water management, driven by precise estimation of crop water requirements, is pivotal for ensuring food security. Water, a critical input for agricultural production globally, significantly influences crop yield. Despite its importance, locally available data on crop water requirements for field crops in the Marathwada region is lacking. This investigation focuses on quantifying the crop water requirement of crops in Marathwada by calculating crop evapotranspiration based on established crop coefficients and reference evapotranspiration. Over a 31-year period (1990 to 2021), daily weather data for eight districts in Marathwada was collected to determine reference evapotranspiration using DSS-ET software. The analysis reveals a specific pattern in the daily evapotranspiration of groundnut across all districts. During the initial growth stage (5^th to 9^th crop week), there is a consistent, albeit slight, demand for water. Subsequently, water requirements gradually increase from the mid-season (9^th to 13^th crop week) to the seasonal stage (16^th to 20^th crop week). Jalna District stands out with the highest crop evapotranspiration at 7.32 mm/day. The highest water requirement for groundnut is observed in Jalna (1038 mm), followed by Hingoli (1020 mm), Parbhani (1007 mm), Nanded (1004 mm), Sambhajinagar (999 mm), Beed (974 mm), and Latur (940 mm), while Dharashiv requires the least water (961 mm) due to its lower temperatures. Spatially, crop evapotranspiration (ETc) for groundnut exhibits regional variations among the eight districts. The southwest and some parts of the southern east of Marathwada have higher ETc, while the northern west regions exhibit lower ETc values. A comprehensive analysis of meteorological data across seven districts using the Mann-Kendall trend test indicates a statistically significant and consistent increasing trend in groundnut meteorological conditions. This promising shift towards more favorable conditions for groundnut cultivation offers valuable insights for farmers and developmental agencies to optimize irrigation water management. Farmers in the Marathwada region can use this data as a guide to determine the appropriate amount and frequency of irrigation for their crops, contributing to sustainable agricultural practices and enhancing food security. The study's findings underscore a positive trajectory in meteorological conditions for groundnut cultivation in Marathwada, emphasizing the importance of adapting agricultural practices to changing climate dynamics for long-term sustainability.