Journal of Water and Irrigation Management
Year:2016 | Volume:6 | Issue:1 |Papers Count:12

Estimating dry biomass is one of the important parts of production estimation. Among vegetation indices, leaf area index (LAI) is the most common used index to estimate water demand and yield. In this study, attempts have made to estimate LAI without destroying plant and by using the AccuPAR-LP80 crop scanner device. The case study performed in Magsal Agro-Industrial Company Qazvin, Iran with the aim of introducing relations to estimate the amount of dry biomass via LAI for three plant- maize, sugar beet and alfalfa. LAI values of above mentioned plants measured through nondestructive method by calibrated AccuPAR-LP80 crop scanner. Statistical evaluation showed that the highest correlation was for maize with R2=0.96 and the lowest was for alfalfa with R2=0.87. In addition, measured dry biomass was a linear function of fraction of photosynthesis active radation (fPAR). Statistical evaluation showed that correlation coefficient varies from 0.94 to 0.90 and PMSE from 2.85 to 3.3 kg ha-1 for maize and alfalfa, respectively.

Performance evaluation of current status of irrigation systems and introducing practical approaches can help to use water more efficiently in field. This study was conducted to evaluate the furrow irrigation systems in corn farms of Moghan agro-industry and husbandry, Parsabad, Ardebil, in 2015.Evaluation of these systems was conducted in seven corn farms. The results indicated that the average water application efficiency, storage efficiency, infiltration efficiency, distribution efficiency, application efficiency of low quarter, distribution uniformity of low quarter and potential efficiency of low quarter are 41.90%, 92.48%, 75.28%, 91.44%, 36.85%, 85.01% and 59.72%, respectively. The reason for the low value of irrigation application efficiency is the difference between application efficiency of low quarter and potential efficiency of low quarter. Therefore, the poor management of surface irrigation was concluded. Proper furrow run and cutoff time and utilizing siphon can improve the current status drastically and will result in irrigation efficiency improvement.

Infiltration is the most important and the most difficult property in evaluation of surface irrigation systems. In this research an optimization technique based on the volume balance approach is developed and evaluated for estimating of Kostiakov-Lewis equation parameters and manning roughness coefficient for open-end downstream condition of border irrigation systems. The infiltration parameters and roughness coefficient were estimated using both advance and runoff data. Six field experiments data of border irrigation used to verify of the proposed method and results compared with the two-point and multilevel calibration methods. Based on the results, multilevel calibration method with average root mean square error (RMSE) 3.7 minutes for advance time and relative error (RE) 0.5% for the runoff volume indicated the highest accuracy. In additional, the proposed method with RMSE 5.3 minutes for advance time and RE 7.7% for runoff volume was in the second place. The two-point method with RMSE 5.8 minutes for advance time and RE 35.3% for runoff volume resulted to the lowest accuracy. The proposed optimization method estimated infiltration parameters and roughness coefficient with relatively good accuracy and it can easily converge and get quick to answers.

The research in the response of plants to deficit irrigation in the regions with limited water resources is very important and leads to reducing water usage in agriculture. This study has been conducted in 2014-2015 in the research field located in Dezful Islamic Azad University in Khozestan as complete randomize block design in four treatments and four replications, 60%, 80%, 100% and 120% of water requirement of maize (KSC.704) under surface irrigation system. Growing season was divided to four periods in which soil water was determined in different soil depths. Grain yield and water use efficiency were determined in the last growth stage. The results show that there is significant difference (1%) in the effect of different irrigation levels in the grain yield. Irrigation treatment of 120% of water requirement increased maize grain yield. Irrigation treatment of 60% plant water requirement decreased vegetative growth because it leads to delaying pollination maturation and yield. Maximum and minimum water used efficiency on the basis of grain yield were related to 80% (2.07 kg/m3) and 60% (1.35 kg/m3) water use efficiency, respectively. Also, there was difference between treatments in soil moisture of different soil depths.

Nowadays with water shortage crisis, increased productivity in the agricultural sector is inevitable. The present study dials with the evaluation of two irrigation systems under different levels of water irrigation on yield, yield components and water use efficiency of corn. The experiments were conducted in a split plot design based on the Randomized Complete Block Design (RCBD) with three replications. The treatments were comprised of three levels of full irrigation, 85% and 70% in main plot and two irrigation systems, furrow and tape irrigation. According to the results the grain yield in drip (tape) irrigation was higher compared to the other system significantly. Applied water in I2 was 1470 m3/ha less compared to that in I1 and water use efficiency was increased 10.5%. In drip irrigation under I2 yield, weight of 1000 grains, number of seeds in a row of corn and number of rows of seed in corn decreased 4.9%, 3.6%, 7.1% and 6.8%, respectively compared to that under I1. According to the results, to achieve higher water use efficiency and less water consumption for corn production in the study region, drip irrigation under 85% of water requirement application in suggested.

The main purpose of this study was to assessment the effects of long-term irrigation with pollutant water on soil physical properties of two water treatment as pollution water and well water during two years (2013 & 2014) on Gharesoo River located in Doroodfaraman district, in 20 km south of Kermanshah. This study was performed in three soil layers 30, 60 & 90 cm with three replications in randomized complete block design. In this study, soil physical properties including saturation hydraulic conductivity (Ks), soil moisture characteristic curve and parameters (qFC, qPWP & AW), bulk and practical density (rb & ra) and porosity (h) were determined. The results of statistical analysis showed that there was no uniform trend between various parameters. Using of the pollutant water was caused a significant difference at 5% level on saturated hydraulic conductivity but on the other physical properties of soil no significant difference were found. The results showed that irrigation with pollution water in loam soil increased saturation hydraulic conductivity ratio significantly but it decreased the moisture in FC, PWP and also bulk and practical density. It can be concluded that the use of pollutant water increased the soil porosity.

The goal of this study was to investigate the effect of salinity and amounts of irrigation water on yield and yield components green pepper (Capsicum annum) variety of green Hashemi in greenhouse conditions. The research was done based on factorial experiment in completely randomized design including three replications as pot planting in Gorgan University of Agricultural Sciences and Natural Resources. Irrigation water quality consist of five levels of salinity (0%, 10%, 20%, 30% and 40% of the mixing sea water and tap water) and the quantity of irrigation water consist of three levels (100%, 125% and 150% of water requirement were considered). Data were analyzed with SAS and the results showed that the effect of irrigation water quantities on length, diameter and length to diameter ratio of fruit was significant (P<0.05). The results showed that effect of irrigation water salinity on number of fruit per plant, fresh and dry weight, plant height, length, diameter and length to diameter ratio of fruit was significant (P<0.01). The interaction effect of salinity and irrigation water quantities on plant height, length and length to diameter ratio of fruit was significant (P<0.01), but diameter of fruit was significant (P<0.05).

Due to the water shortage in Iran, the use of new resources such as wastewater and proper management is necessary. The main goal of this research is to study the effect of some heavy metals concentration (Pb, Cd, Cu, Fe and Zn) on the bell pepper and soil in randomized complete block design using six treatments including T1 (100% wastewater), T2 (75% wastewater+25% well water), T3 (50% well water+50% wastewater), T4 (25% well water+75% wastewater), T5 (100% well water) and T6 (100% well water and chemical fertilizer) and three replications in a greenhouse located in Lorestan agriculture college.According to the results, irrigation with treated wastewater has no meaningful effect on lead and cadmium concentration in soil (1% level) but Cu, Zn and Fe concentration in the soil was meaningful in the 1% level. In the bell pepper fruit, Pb, Cd, Cu and Zn but Fe concentration was not meaningful in 1% level under the effect of irrigation treatments. Generally, not only use of Khorramabad urban wastewater does not increase the heavy metal concentration in soil and plant more than standard level but it prevents the use of chemical fertilizer so it is important for consumer health. Since wastewater contains important nutrients needed for plants, correct management in considered region decreases chemical fertilizer consuming.

To consider the effect of irrigating with Salman Farsi Agro-Industry Sugar Cane Drain Water Farms on chemical properties of soil, a research was conducted with a completely random scheme framework at irrigation and drainage research farm of the Faculty of Water Sciences Engineering of Shahid Chamran University of Ahvaz. Irrigation treatments were included mixing of Salman Farsi Agro-Industry Sugar Cane Drain Water Farms and Karun River water: (1) mixing 75% Karun River water+25% sugar cane drain water farm, (2) mixing 50% Karun River water+50% sugar cane drain water farm, (3) mixing 25% Karun River water +75% sugar cane drain water farm, in three repetitions. The control treatment (100% Karun River water) was selected in one repetition. Chemical properties of soil were measured during four months and in three depths (0-30, 30-60, and 60-90 cm). Analysis of the results showed that with increasing the salinity of irrigation water the amount of calcium decreased, though it was not significant (P<0.05). The amount of magnesium, exchangeable sodium, absorbable potassium, chlorine, and bicarbonate of soil increased significantly (P< 0.05), while carbonate was stable.

The Beerkan single ring infiltration experiment is receiving more attention because of its simplicity and low expense in running in recent years. BEST slope algorithm is the original algorithm in Beerkan experiment, which estimates some soil hydraulic properties such as saturated hydraulic conductivity (Ks) and sorptivity coefficient (S).The purpose of this research is to compare the performance of BEST slope algorithm with a simple proposed method and to determine the value of a constant parameter as the ratio of gravity force to capillary force (α) for loam and sandy loam soils. For this purpose, a number of 113 beerkan infiltration experiments were carried out in Sistan research field. The results showed that the estimated Ks values for 31 selected experiments, in which the relative fitting error (Er) for each test is less than 5.5% are similar to those obtained for 59 selected experiments having an average Er of less than 5.5%. However, these results were largely different from those obtained for 101 selected experiments having an average Er of less than 10%. Overall, the magnitude of α for loam and sandy loam soils of study area was determined as the average of two α values obtained for 31 and 59 selected experiments and it is equal to 0.013.

The plant response of salinity and drought stresses and the role of them to reduce water absorption are expressed by several mathematical models. The reduction functions are classified additive, multiplicative and conceptual models. In this study six different macroscopic reduction functions, using data from greenhouse tomatoes, were evaluated: Van Genuchten (additive and multiplicative), Dirksen et al., Van Dam et al., Skaggs et al. and Homaee. The experiments were carried out on tomato plant in a factorial randomized complete block design with three replications. The treatments consist six levels of salinity (1, 2, 4, 6, 8 and 10 dS/m), and four levels of irrigation water (50%, 75%, 100% and 120% of crop requirement). The result indicated that in the absence of salinity stress all models were fit to the data measured, so, the results indicated that at low salinity levels, plant response to both water and salinity stress was additive and Van Genuchten additive model could simulated water uptake very well, while at higher salinity levels from 4 dS/m multiplicative models are a better fit. Among of multiplicative models, Skaggs et al. and Homaee models provided better fitness to measured data for tomato than other function, so as optimal absorption models are recommended.

The saline waters usage is a suitable way for supply of agricultural sector water. This research was carried out in a randomized complete block design with four treatments and three replications on Ziziphus mauritiana seedlings. The treatments were irrigation water shaving electrical conductivity of 0.3, 3, 6 and 9 dSm-1. The results showed that irrigation water salinity had significant effect on leaf number, leaf chlorophyll, stem diameter and shoot wet and dry matter and relative water content. The leaf number, shoot wet and dry matter and relative water content decreased significantly with increasing irrigation water salinity from 6 to 9 dS m-1. These characters decreased 36.1%, 38.6%, 23.3% and 23.9%, respectively. There were no significant difference in seedling vegetative characters between waters having electrical conductivity of 3 and 6 dSm-1. The salinity production functions were estimated in various equations of linear, quadratic, cubic, logarithmic and exponential. The results showed that all equations except exponential could estimate shoot dry matter more than actual data. The cubic equation had the best accuracy for Ziziphus mauritiana seedlings.