An Attempt to Modify the Crop Coefficient Value of Wheat and Chickpea for Humid Subtropical Climate of Varanasi District, Uttar Pradesh
Chandra Kishor Kumar
Department of Farm Engineering, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, U,P., India.
Gaurav Sharma *
Central India Hydrology Regional Centre, National Institute of Hydrology, Bhopal, M.P., India.
Anshu Gangwar
Krishi Vigyan Kendra, Piprakothi, East Champaran, DRPCAU, Pusa, Bihar, India.
*Author to whom correspondence should be addressed.
Abstract
Crop water requirement is one of the essential components that should always be taken into account wherever water management strategies are adopted for effective utilization of water. In India agriculture is considered as the backbone of economy but nothing technical or advance technology has being adopted for its advancement and still major portion of agriculture are dependent on the verge of monsoon. Therefore crop coefficient (Kc) value for wheat and Chickpea as a function of relative humidity, wind speed and crop height has been formalized in this study for efficient use of available water. The empirical formula was applied for estimating Kc(mid) and Kc(end) values for humid subtropical climate of Varanasi. The corrected crop coefficient value of wheat for Kc(mid) was found to be 1.12 and for end season Kc(end) corrected was found to be 0.42. Mean maximum height of wheat crop in mid-season was obtained as 0.80 m and for the end season mean maximum height was found to be 0.99 m. The corrected crop coefficient value of Chickpea for midseason was found to be 0.98 whereas it was found out to be 0.38 at Kc(end). Mean maximum height of chickpea crop in mid-season was obtained as 0.39 m and for the end season of the crop mean maximum height was found to be 0.52 m. Crop coefficient curve for wheat crop was prepared in which X-axis represents time in days and Y- axis represents crop coefficient value for wheat. A third-order polynomial equation (y = -3E - 06x3 + 0.0005x2 - 0.0039x + 0.3702) has been obtained for wheat crop with correlation coefficient of 0.97. Similarly, graphical plot was constructed for chickpea crop and a third-order polynomial equation (y = -2E - 06x3 + 0.0002x2 - 0.0004x + 0.3732) has been obtained with correlation coefficient of 0.98. Furthermore, third-order polynomials were fitted well to predict the crop coefficient values as function of growing degree-days (GDD).
Keywords: Chickpea, crop coefficient, polynomial equation, crop water requirement, wheat