Calibration of Crop Coefficients and Evapotranspiration Rates in Semi-Arid and Sub-Humid Agro climates: Impact on Crop Water Requirement
| Main Authors: | Kartik V Jakkannavar, Tejaswini N Bhagwat |
|---|---|
| Format: | Article |
| Bahasa: | eng |
| Terbitan: |
, 2020
|
| Subjects: | |
| Online Access: |
https://zenodo.org/record/3734002 |
Daftar Isi:
- Abstract: Crop water requirement, a key component for Irrigation planning and management depends on Actual Evapotranspiration rates. Variations in Evapotranspiration rates depends on the climatic conditions for a given soil and crop. The objective of this work is to determine the water consumptive use based on crop coefficients for Tomato in Semi-arid and Sub-humid agro climates. The Actual Evapotranspiration was quantified by Lysimeters. Sieve analysis of the soil indicated as sandy soil and has density of 1.859*10-3 Kg/cm3. Depending on density and the root depth of tomato crop, lysimeter of dimensions 52cm depth and 36cm diameter is used to measure actual evapotranspiration rate. Regression analysis carried out for the actual evapotranspiraton rates, computed using empirical formula indicated that the FAO-56 PM method is well suited for both the regions having correlation coefficients of 0.94 and 0.92 for Semiarid and sub-humid regions respectively. Further, it was found that Thornthwaite equation being the next suited method has a correlation of 0.90 for semiarid and Hargreaves method the next suited method with correlation of about 0.90 for sub-humid. Crop coefficients used in all this potential Evapotranspiration methods were calibrated with lysimeter insitu measurements. The crop coefficients vary depending on the different crop stages. The recalibrated crop coefficients for tomato crop are 0.78, 1.045, 1.95 and 1.54 for initial, development, mid and late respectively for Semi-arid Agro-climate. Similarly for Sub-Humid agro climate the crop coefficients were found to be 0.9, 0.98, 1.55 and 1.3 respectively.