Crop water requirement (ETc) of different crops of middle Gujarat

Abstract

Accurate estimation of crop water requirements (ETc) of any crop is essentially required for irrigation scheduling and water management. The present study was undertaken to estimate the crop water requirement (ETc) of ten major crops (rice, wheat, maize, pearl millet, chickpea, green gram, soybean, groundnut, mustard and cotton) grown in different seasons inmiddle Gujarat region. The daily reference evapotranspiration (ETo) was estimated by FAO Penman-Monteith method using 20 years (1993 to 2013) mean meteorological data of Anand. The growth stage wise crop coefficients (Kc) modified for daily climatic variation was used to estimate the daily ETc for the selected crops.The daily ETo was found to increase continuously from 4.2 mm day-1 in January to its maximum values of 10.1 mm day-1 during 25th-30thMay, thereafter ETo decreased sharply during June and remained low during July and August (H”5.4 mm day-1). With slight increase during September and October, it decreased further and reached to its minimum value (4.0 mm day-1) at the end of year. The seasonal crop water requirement (ETc) estimates showed that, among summer crops, groundnut has higher ETc (849.0 mm) value than pearlmillet (499.2 mm) and green gram (476.5 mm).Among kharif crops,cotton (848.0 mm) and rice (729.3 mm) have the highest crop water requirement whereas pearlmillet (323.6 mm) and green gram (324.6 mm) have the lowest ETc. Amongst winter season crops,wheat has the highest (501.2 mm) ETc and mustard has the lowest (411.7 mm) ETc.These results can be used in efficient management of irrigation water.

Keywords

• Reference evapotranspiration
• crop water requirement
• crop coefficient
• cereals
• pulses,
• oilseeds,