Evaluation of GEP and ANN in reference evapotranspiration modelling and a study on effect of PRD irrigation on growth, yield and water productivity of Broccoli
| dc.contributor.advisor | Singh, P.K. | |
| dc.contributor.author | Pangam, Heramb | |
| dc.date.accessioned | 2020-11-20T07:30:12Z | |
| dc.date.available | 2020-11-20T07:30:12Z | |
| dc.date.issued | 2020-10 | |
| dc.description.abstract | Irrigated agriculture has contributed for improving production and productivity in conjunction with other agronomic measures in most parts of the country. On-farm water management for optimal use of the water available with the farmer should be given priority. The precise application of water can be achieved by using water saving techniques like drip and sprinkler in addition to accurate estimation of total water requirement for each crop using different methods. This study was taken up to check the Gene Expression Programming (GEP) and Artificial Neural Network (ANN) techniques for finding suitable models for the estimation of reference evapotranspiration using different input combinations in sub-humid tarai region of Uttarakhand, India.The modelling of ET0 applying both GEP and ANN techniques were done using the daily meteorological data of Pantnagar station for the period of 2010 to 2019. Total of 15 combinations of inputs were used for the development of models. The model with the least number of inputs consisted of only the maximum and minimum air temperatures whereas the model with highest number of inputs consisted of maximum air temperature, minimum air temperature, mean relative humidity, number of sunshine hours, wind speed at 2 m height and extraterrestrial radiation as inputs and with the reference evapotranspiration as the output for all the models. Partial root zone drying (PRD) is a potential deficit irrigation technique. This study investigated the effect of different PRD treatments at different irrigation levels on growth, yield and water productivity of broccoli crop in an open field at Vegetable Research Centre (VRC), G B Pant University of Agriculture & Technology, Pantnagar, Uttarakahnd (India). The results indicated that the model with higher the number of inputs gives more accurate estimation of reference evapotranspiration. It was also found that the addition of extra-terrestrial radiation improved the accuracy of estimation in most of the models developed. On comparing models with the same input combination, it was seen that ANN models performed better than GEP models. The results pertaining to PRD showed that the treatment that used 1PRD at 100 percent level of total water requirement has the highest marketable yield as 10.96 t ha-1 while the treatment of fixed PRD at 50 % of total water requirement recorded the lowest marketable yield with a value of 9.92 t ha-1. The highest water use efficiency and water productivity was found in the treatment with 1PRD and 50 % of total water requirement with a value of 0.05265 kg/ m2–mm and 19.13 L/kg, respectively. The treatment with FPRD with 100 % of total water requirement gave the lowest water productivity that is highest amount of water used (21.62 L/kg) for producing unit kilogram of broccoli. Therefore, it is concluded that PRD can be used as a deficit irrigation technique without any significant reduction in productivity of broccoli crop under drip irrigation with high water productivity. | en_US |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810155367 | |
| dc.keywords | evapotranspiration, models, irrigation, growth rate, Broccoli | en_US |
| dc.language.iso | English | en_US |
| dc.pages | 167 | en_US |
| dc.publisher | G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand) | en_US |
| dc.research.problem | Broccoli | en_US |
| dc.sub | Irrigation and Drainage Engineering | en_US |
| dc.theme | Evapotranspiration | en_US |
| dc.these.type | M.Tech. | en_US |
| dc.title | Evaluation of GEP and ANN in reference evapotranspiration modelling and a study on effect of PRD irrigation on growth, yield and water productivity of Broccoli | en_US |
| dc.type | Thesis | en_US |