Showing 3 results for Shahinrokhsar
Shahinrokhsar , Shokri , Asadi, Davari, Peyvast,
Volume 14, Issue 53 (fall 2010)
Abstract
Nowadays in the world, soilless culture as a kind of technique is known to give vegetable crops higher yield and quality. This experiment was conducted at research greenhouse of Agriculture and Natural Research Center of Golestan province in spring 2005. The purpose of this research was to investigate the effects of irrigation frequency and substrates on yield and fruit quality of greenhouse tomato (CV. Hamra). Irrigation was carried out for 4, 8 and 12 times a day. The substrates were Perlite, Leca and Perlite + Leca (1:1, w/w). The experimental design was factorial in the form of randomized complete design with four replicates. The substrates used in the experiment had no effect on most factors. However, TA (0.43 mg/100 l) and fruit set (48%) were increased significantly by perlite and Leca substrates, respectively. The results indicated that higher and lower marketable yields were obtained from plants irrigated 12 (1830.5 g/plant) and four times (1156.7 g/plant) per day, respectively. Also increasing irrigation schedule decreased the Titratable acidity but didn't significantly affect the other factors. According to these results, Irrigation of 12 times per day and Leca substrate increased vitamin C and marketable yields, leading to optimum quality and quantity fruit set and the decreased TA (0.33 mg/100 l) in fruits in this treatment.
P. Shahinrokhsar, M. E Asadi,
Volume 16, Issue 61 (fall 2012)
Abstract
Modification of irrigation scheduling and management improvement of irrigation systems are two essential factors that have significant impact on agricultural water use efficiency. Therefore, a field experiment was conducted to evaluate the effect of tape drip irrigation (T) and furrow irrigation systems (S) under different irrigation regimes on yield and yield components of soybean in growing season of 2006-2007 at Gorgan Agricultural Research Station in north part of Iran. The experiment was laid out in a split plot design in a randomized complete form where each treatment was replicated three times. The main plots were irrigation systems of tape and furrow, and three irrigation regimes 100 (I100) , 75 (I75) and 50 (I50) percent of total irrigation requirement were chosen as secondary plots. Results showed that thousandgrain weight (gr) and plant height (cm) in furrow irrigation were significantly more than the tape drip irrigation method. Also significant differences between different irrigation regimes in terms of plant height, node numbers and yield were observed. So, I100 and I50 had highest and lowest values, respectively. In terms of irrigation system, 63 percent of water consumption was reduced in tape drip irrigation method. Also, the results indicated that higher and lower water use efficiencies were obtained from tape drip irrigation method with I50 treatment (1.09 kg m-3) and furrow irrigation with I100 treatment (0.50 kg m3), respectively.
F. Javadzadeh Shakhali, M. Khaledian, M. Navabian, P. Shahinrokhsar,
Volume 20, Issue 75 (Spring 2016)
Abstract
Soil moisture is one of the main input parameters in many models for monitoring and predicting crop yield. The ability of mathematical models has allowed correct application of brackish water and selection of management options. The purpose of this research was to evaluate the performance of HYDRUS-2D for simulating soil volumetric water content in a heterogeneous heavy soil under field conditions. Three volumes of irrigation water (10, 15 and 20 L) and three salinity levels of irrigation water (1.279, 2.5 and 5 dSm-1) were exerted in a linear drip irrigation system with three replications. In order to check the amount of soil volumetric water content, soil profiles were drilled to 40 cm depth and vertical wall of drip irrigation line was networked. Soil volumetric water content was measured with a TDR MiniTrase kit 6050X3K1B model. The observed soil moisture values were compared with the simulated ones using statistical indices (i.e. nRMSE and CRM). The results indicated that mean soil volumetric water content distribution in irrigation water with different levels of salinities was in the range of field capacity. The range of nRMSE values varied from 0.91 to 2.07 percent in different replications. According to calculated nRMSE values, performance of the simulation model, was ranked as excellent for simulation of soil volumetric water content. Range of CRM values was shown to be from -0.0080 to 0.0170 that was really low. Results of these two statistics indicate high ability of the model in simulating soil volumetric water content using estimating hydraulic parameters by inverse solution.
