International Journal of Agricultural Engineering

R. Ganesh Babu ¹, G. Ravi Babu ¹, H. V. Hema Kumar ²

Affiliations
1 Department of Soil and Water Engineering, College of Agricultural Engineering, Bapatla (A.P.), IN
2 Department of Agricultural Structures, College of Agricultural Engineering, Bapatla (A.P.), IN

Abstract

Land and water resources are the basic needs of agriculture and for the economic development of any country. As water becomes increasing scare and increasing demand for irrigation water, everywhere, has now focused national attention and public interest on utilization of existing water supplies, integrated irrigation water conservation and management policy and practices. Accurate quantification of evapotranspiration is crucial for better management and allocation of water resources. It is important that the water requirements of crops are known at different management levels within the irrigated area to accomplish effective irrigation management. Estimation of the evapotranspiration and effective rainfall are extremely useful for operation planning and management issues. CROPWAT is a computer model, was used to estimate the reference evapotranspiration, effective rainfall, crop water requirement and irrigation water requirement for the Bapatla region in Andhra Pradesh state, India. Daily meteorological data including rainfall, maximum and minimum temperatures, relative humidity, wind speed and sunshine hours were collected for the period of 2009 to 2013 and used as input data for CROPWAT. Average peak monthly ET₀ was observed to be 8.09 mm/day for the month of June and followed by the 7.55 mm/ day for the month of May. Whereas average minimum ET₀ were observed as 3.85 and 3.92 mm/day in the months of December and January, respectively. The average effective rainfall was estimated for the study area as 769.3 mm out of 1060.3 mm annual rainfall. The crop water requirement (ETc) and irrigation water requirement were estimated for vegetable crops during Rabi season in the study area (Bapatla) as 516.3 mm and 470.4 mm, respectively.

Keywords

CROPWAT, Effective Rainfall, ET₀, Crop Water Requirement, Bapatla Region.

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R. Ganesh Babu ¹, I. Bhaskara Rao ², K. N. Raja Kumar ³

Affiliations
1 Department of Soil and Water Engineering, College of Agricultural Engineering, Bapatla(A.P.), IN
2 Department of Soil and Water Engineering, College of Agricultural Engineering, Bapatla(A.P.), IN
3 Department of Agricultural Structures, College of Agricultural Engineering, Bapatla(A.P.), IN

Abstract

A field experiment was conducted at College of Agricultural Engineering, Bapatla during Rabi 2014 to evaluate the response of different levels of irrigation through drip irrigation to find out appropriate irrigation level which leads to higher water use efficiency and yield of okra. The irrigation water was applied at 1.00 CWR (Crop water requirement), 0.80 CWR and 0.60 CWR through drip irrigation system. The crop water requirement was estimated for vegetable crops at study area as 516.3 mm during Rabi season using CROPWAT based on the climate data, rainfall data, crop data, cropping pattern data and soil data. Okra crop irrigated with drip irrigation at 0.80 CWR recorded the better growth i.e. good plant height and ischolar_main length than the other treatments. Okra crop irrigated with drip irrigation at 0.80 CWR recorded the highest benefit cost ratio i.e. 3.15, which recorded 21.47 per cent more yield than the traditional method of irrigation and it was recorded the better water use efficiency as 0.143 t/ha-cm.

Keywords

Okra, Drip Irrigation, Different Irrigation Levels, CROPWAT.

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