To calculate the water needs of different Vegetables cultivated with a sub- surface drip irrigation system in Himachal Pradesh
Authors: Tripathi Mahesh 
Published: March 2024

Abstract
CropWat Model 8.0 is a crop water requirement estimation tool developed by the Food and Agriculture Organization (FAO) of the United Nations. The model can be used to estimate crop water requirements, irrigation requirements, and crop water productivity for a wide range of crops in different agro-climatic regions. In the case of Himachal Pradesh, which is a mountainous state in northern India, the use of sub-surface drip irrigation (SDI) system can help conserve water and increase crop productivity. The CropWat Model 8.0 can be used to estimate the crop water requirements for various crops grown in this region using SDI. To use the model, you would need to gather data on the climate, soil, and crop characteristics for the region. This would include data on rainfall, temperature, humidity, wind speed, solar radiation, soil type, and crop type. You would also need to have information on the characteristics of the SDI system, such as the depth of the drip lines, the spacing between the lines, and the emitter flow rate. Once you have gathered the necessary data, you can input it into the CropWat Model 8.0 software to estimate the crop water requirements for the different crops grown in the region using SDI. The model will provide estimates of the water requirements for each crop at different growth stages, which can help in designing an efficient irrigation schedule. Some of the crops that can be grown in Himachal Pradesh using SDI include fruits such as apples, pears, and peaches, as well as vegetables such as tomatoes, cucumbers, and peppers. The CropWat Model 8.0 can be used to estimate the water requirements for these crops and help in designing an optimal irrigation schedule to maximize crop yield while minimizing water use. The investigation is conducted into resolve the water need of a few chooses vegetable crop in the Chhapang area of Eternal University, Baru Sahib Sirmour, India. The study initiate that the water demands of the vegetables crop was highest during an pre-flowering and flowering stages, and that water requirements decreased during the post-fruiting stage. The study also showed that the water requirements of different crops varied depending on the type of crop. This study helps us understand how much water different vegetable crops need to grow. Some vegetable crops were included for two seasons. Using climate data, crop evapotranspiration (ETc) and reference crop evapotranspiration (ET0) were flexible for all crop using CROPWAT 8.0. The investigations show that vegetable crops in the Rabi season do not receive adequate effective rainfall to satisfy their water needs ("Vegetable crops in the Rabi season do not receive adequate effective rainfall to satisfy their water needs.") Hence, Irrigation is essential for vegetable crops to ensure that they receive the necessary amount of water for optimal growth and development. Without adequate water, vegetable crops will not be able to reach their full potential and may suffer from drought stress. Irrigation can also help to reduce the risk of disease and pest infestations, as well as improve soil fertility. Additionally, irrigation can help to conserve water by reducing the amount of water lost through evaporation. However, for the equal vegetables crop in the Kharif seasons, efficient rainfall stands sufficient to compensate for the crop water requirements. It was found that the average water productivity based on subsurface drip irrigation, sprinklers irrigation and flood irrigation system was calculated. An increase of 72% in water productivity was observed when flood irrigation systems were replaced by sprinkler irrigation systems. Similarly, a 118% increase in water productivity was found if a flood irrigation system is replaced by a subsurface drip irrigation system.