7
atefeh roudbari; ali bagheri
Abstract
Unfortunately, at some meteorological stations, there are no facilities for measurement of some weather parameters, so, they should be estimated. Therefore, determining the correctness of the reference evapotranspiration (ETo) method by using the estimated data is very important. Based on this, the objective ...
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Unfortunately, at some meteorological stations, there are no facilities for measurement of some weather parameters, so, they should be estimated. Therefore, determining the correctness of the reference evapotranspiration (ETo) method by using the estimated data is very important. Based on this, the objective of the present study was to evaluate the performance of the Penman-Monteith method for estimating ETo in Mazandaran Province, Iran, when solar radiation (Rs), vapor pressure (ed) and relative humidity (RH) data are not available. Data of Sari, Qarakheil, and Amol synoptic stations were used to compare the estimated ETo by the Penman-Monteith method for the complete and limited data sets. The results showed that when RH and ed data were missing, the Penman-Monteith method was still a very good option for estimating ETo in Sari, Ghaemshahr and Amol station, with RMSE values smaller than 0.3 mm day-1. However, when Rs was missing, the Penman-Monteith method was not good enough for estimating ETo, and RMSE increased to more than 1 mm day-1. The results also showed that solar radiation was the most effective parameter on ETo estimation and both vapor pressure and relative humidity had the same effect on ETo estimation.
7
Mahsa Rahimi pool; Davod Akbari Nodehi; Reza Asadi; Ali Bagheri; Fazl Shirdel Shahmiri
Abstract
Due to the importance of rice cultivation, especially in Mazandaran Province, it is necessary to plan carefully for the optimal use of water resources in the province in the agricultural sector, especially rice, to reduce water demand for rice production. For this purpose, an experiment was conducted ...
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Due to the importance of rice cultivation, especially in Mazandaran Province, it is necessary to plan carefully for the optimal use of water resources in the province in the agricultural sector, especially rice, to reduce water demand for rice production. For this purpose, an experiment was conducted in the form of a complete block-design with three replications and four treatments using Tarom Hashemi cultivar, during the 2021 crop year in the Rice Research Institute of Iran-Amol. Treatments included conventional planting with flood irrigation (T1) and drip irrigation (T2), transplanting in un-puddled bed with drip irrigation (T3) and direct seed cultivation in dry bed with drip irrigation (T4). The results showed that the cultivation method was effective on yield, plant height, water consumption and irrigation water, water productivity and water use efficiency and was statistically significant at 1% and 5% level of probablity. The highest and lowest yields belonged to T1 and T4 treatments with 4079 and 2876 kg/ha, respectively, and T2 had the highest water productivity with 0.61 kg/m3, which had no significant difference with T1. The lowest water productivity belonged to T4 with 0.45 kg/m3. The highest and lowest irrigation water productivity belonged to T2 and T1 with 0.67 and 0.52 kg/m3, respectively Based on the results, conventional planting with drip irrigation did not have a significant reduction in yield compared to conventional planting with flood irrigation and increased water productivity by saving water consumption Therefore, the conventional planting method with drip irrigation was recognized as the best treatment in this study.