نادر کوهی چله کران

In this study, volume of irrigation water, water productivity, and yield of alfalfa were measured in 300 farms in Zanjan, Fars, Chaharmahal and Bakhtiari, Hamedan, East Azerbaijan, Semnan, Khorasan-Razavi, Isfahan, West Azerbaijan, Central, Qazvin and Kerman provinces under farmers management and surface and sprinkler irrigation, various water sources, different water salinities, soil conditions, and varieties, during the growing season of 2018-2019. The results showed that the difference between average volumes of water applied by farmers, yield, and water productivity, in the studied sites were significant at 1% probability level. The average amount of applied water by farmers was 8502, 8901, 9226, 9459, 11481, 12796, 14311, 14821, 15198, 15916, 18351 and 23920 m3/ha, respectively, and the average was 13284 m3/ha. The dry yield of alfalfa varied from 2500 to 30000 kg/ha with an average of 13841 kg/ha. Irrigation water productivity varied from 0.2 to 4.5 and its average was 1.28 kg/m3. The average irrigation water plus effective rainfall productivity for alfalfa was 1.19 kg/m3. The results showed that the average applied water and alfalfa yield in surface and sprinkler irrigation methods were 15076 and 10653 m3/ha, respectively, (p<1%). These results showed that in sprinkler irrigation method, applied water was 30% less and irrigation water plus effective rainfall productivity was 41% higher. Accordingly, in order to reduce the volume of irrigation water and improve alfalfa water productivity, it is recommended to use sprinkler method in suitable climatic conditions where irrigation water is of good quality and the technical criteria of design, implementation, operation, and economic considerations are met.

In spite of the drought conditions and lack of water in most parts of Iran, fodder corn is one of the main producers of silage fodder in the country. For the purpose of investigating the effects of subsurface drip irrigation systems on fodder corn cultivation and determining the efficiency of water consumption, a split plot design was conducted at Jopar Kerman Agricultural Research Station for a period of two crop years using randomized complete block designs with three replications. In the research, three levels of irrigation (I1=100, I2=75, and I3=50 percent of the water requirement) were assessed as the main factor, and two depths of subsurface pipes with drippers (inline) were assessed as the submain factor. Among the treatments of different irrigation levels, the treatment of 100% water requirement obtained the highest yield by producing 77250kg/ha of wet fodder and 15447kg/ha of dry fodder. A 20% and 52% yield difference was observed between the 100% water demand treatment and the 75% and 50% water demand treatments. In terms of WP, there was a significant difference between the two treatments of 30 cm soil depth and 40 cm soil depth; the highest WP was observed in the 30 cm soil depth treatment. In both years of the study, the irrigation treatment of 50% of the water requirement had the lowest WP (average 1.2 kg/m3). Additionally, the average amount of water consumed by the treatments of 50, 75, and 100% of fodder corn water requirements was 3200, 4100, and 5200 m3/ha, respectively. As a result of the results of this research, it has been recommended that for the production of fodder corn in the Jopar Kerman region, a planting depth of 30 cm with a 100% water requirement under subsurface drip irrigation with a water consumption of 5200 m3/ha will be used

The aim of this study was to investigate the interaction of irrigation regimes and drip-line installation depth on Rapeseed water productivity. The results showed that the effect of different irrigation regimes (I) on all studied traits in Rapeseed (grain yield, 1000-seed weight, number of pods, pod length, number of branches) and water productivity had a significant effect (P <0.01). Increasing the drip-line depth had a negative effect on the Rapeseed yield, yield components and water productivity. So that, the highest amount of each of the mentioned traits was observed at a depth of D1 (30 cm). Differences of 21 and 59% in the first year and 22 and 58.8% in the second year between I2 and I3 treatments with I1 treatment indicate this superiority. The highest water productivity in each of the drip-line depth was allocated to the I2 treatment. It seems that despite the lower consumption of water in the I2 treatment, the performance obtained from this treatment has increased the water productivity compared to the I1 treatment. The interaction effects of different irrigation regimes and drip-line depth showed no significant effect on yield, yield components and water productivity. Considering that the drip-line depth of 30 and 40 cm did not have much effect on the studied traits, however, it is a better choice considering that by placing irrigation pipes at a depth of 40 cm, plowing operations can be extended to depths.

Correct cultivar choice of corn and provide an efficient irrigation method to save water and increase production per unit area and the optimal use of water resources is very important. This study was carried out to investigating changes in yield and water productivity in different maize hybrids (KSC 704 and KSC 410) under irrigation management using strip drip and furrow Irrigation methods during two years of 2015-2016 in Jopar research station in Kerman province. The experiment was arranged in a split-plot design over randomized complete block design. The results showed that maize hybrids had significant effect on yield and its components at 1% level. The highest grain yield was observed in KSC 704 (13385 kg/ha) compared to KSC 410. The strip drip irrigation method had the highest grain yield (13376 kg/ha) compared to furrow irrigation method. The effect of interaction between irrigation method and maize hybrids showed that the strip drip irrigation method with maize hybrids, KSC 704 recorded higher yield (14128.5 kg/ha.), and an 11% increase in yield compared to maize KSC 410. Also, the lowest amount of irrigation water was 6765 m3/ha and was observed in KSC 410 under strip drip irrigation method. Strip drip irrigation method reduced water irrigation by 33.5% and 36.25% in KSC 704 and KSC 410 treatments, respectively. Also, the water productivity in the strip drip irrigation and farrow irrigation method was equal 1.84 and 0.98 kg/m3 under water storage condition. To increase water productivity and reduce irrigation water, farmers can benefit from drip irrigation due to the profitability of this irrigation method.

Drought is one of the factors that threatens the performance of agricultural products, especially corn in most parts of the world. Under conditions of water scarcity, the effectiveness and efficiency of fertilizer use is reduced, especially if fertilizer application is not consistent with plant growth. Among fertilizers, nitrogen is one of the most important nutrients for corn, and consumption management of this fertilizer has great importance in order to succeed in increasing the production of corn. Therefore, in conditions of water shortage, balanced and optimal use of fertilizer should be considered to achieve increased yield and water use efficiency.

This study was conducted to investigate the effect of drip irrigation regimes and different levels of nitrogen fertilizer on yield and yield components of corn and soil moisture changes at the Shaheed Zendrh Rouh Jupar in Kerman province during the years of 2012-2014. The experiment was arranged as a split-plot design based on randomized complete block design with five irrigation regimes (I1 = 100, I2 = 80 and I3 = 60% ETc) as the main-factor and five nitrogen fertilizer level N1 = 0, N2 = 50, N3 = 100, N4 = 150 and N5 = 200 kg/ha) as sub-factor. According to the Kerman Meteorological Station, this region has a semi-arid climate with warm summers and mild winters. To calculate the volume of water consumed, potential evapotranspiration (ETo) was determined using daily meteorological information and Penman-Monteith method (PM). A sampling method was used to measure moisture at different depths of soil.

The results showed that the highest yield was due to I1 treatments with 8.85 t/ha, and there was a direct relation between crop reduction and water requirement reduction at all stages of crop production. High nitrogen application had a negative effect on yield. Typically, in soils that lack nitrogen, corn grain yield increased with nitrogen addition. However, after reaching the maximum yield, nitrogen addition has no effect on increase or yield may reduce. The interactions of different levels of water and fertilizer showed that I1N4 and I3N1 treatments had the highest (10.6 ton/ha) and lowest (1.24 ton/ha) value of corn yield, respectively. The highest and lowest grain yield components (thousand grain weight, number of kernels row, number of kernels per row, cob length, cob diameter) were observed in N1 and N3 I1 treatments, respectively. The highest water use efficiency (1.26 kg/m3) was observed in I2N4 treatment and the lowest (0.068 kg/m3) in I3N1 treatment. The results of this study showed that the remaining moisture content in soil decreased by decreasing amount of irrigation water and nitrogen fertilizer in 20 days after planting. At 75 days after planting, reasons such as severe water shortages during growth, reduced root density, high water requirement at this stage of growing season, and the plants need to nutrients have probably caused the roots to absorb as much as possible of the top three water and nutrient. As a result, the moisture that reaches the last layer is less. The results showed that in the last stages of growth compared to other stages, the plant water requirement is reduced and excess water penetrates the lower layers.

According to the results of this study, nitrogen fertilizer at 150 kg/ha with 100% water requirement is the best combination for corn farming in semi-arid climates.

Due to the geographical location of Iran and its location in arid and semi-arid, dehydration and agricultural drought are always threatening it. Drip tape irrigation (Tape) is an example of pressurized irrigation systems used for efficient use of water. To determine the timing and amount of irrigation is very complex because of dependent factors. This complexity is one of the problems that farmers and experts confront it. The purpose of this study is to evaluate the different levels of irrigation using drip tape irrigation (Tape) and to determine the required water using Tensiometer in corn cultivation. A complete randomized block design experiment was conducted at Kerman Agricultural Research Station with three replications and four irrigation treatments. It included 3 suction treatments 1.2FC, 1.5FC or 1.8FC and the 4th treatment- irrigation water requirement of the plant (the control treatment)-for three years (2010-2012). To determine the irrigation time using tensiometer when the water extraction for each of the treatments reached to 1.2FC, irrigation was done. With regard to the interval and amount of irrigation in treatments, the control treatment had the highest yield and the most efficient water use. However, the treatment of 1.2FC had the closer performance to the control treatment than other treatments. The amount of water used in treatments was almost equal. Although treatments 1.5FC and 1.8 FC had a little more water consumption than the treatment 1.2FC, the yield of treatment 1.2FC was better in all plant parameters because its irrigation interval was lower than other treatments and the plots were irrigated sooner. According to the findings, the treatment FC1/2 which needs no calculation can be recommended to the farmers.

Crop growth models facilitate management of irrigation water and fertilizer because less on-site (filed) visits and direct measurements are required. On the other hand, these models are complex and difficult to be understood and require input data that is not available, thus, using them in management decisions, which should be done before cultivating season, will be difficult. The objective of this study was to develop a model for grain yield prediction of Corn (Zea maize) based on simulated leaf area index (LAI) under water stress conditions. In this study, corn LAI was simulated based on cumulative degree-days and water stress index. The model used crop and soil as well as meteorological data including daily maximum and minimum air temperature (oC), precipitation (mm), and solar radiation (MJ.m-2d-1). The model was developed based on the 2013 growing season data for single cross 704 cultivar under full irrigation and water stress conditions, and was validated with 2014 growing season data. The highest values of simulated LAI in the 100% water requirement (WR) treatment were between 6.14 and 5.78, in the 80% WR between 5.63 and 5.4, and in the 60% WR was between 4.11 and 3.47, which varied by 0.13 (2%), 0.14 (2.5%) and 0.29 (6.6%), respectively. In the mid- stage of growth, the estimated LAI was more consistent with measured values (2%). In treatments under stress (except for the fourth stage of sampling), the LAI estimated by the model was 6.6% higher than the values observed. In all treatments, the high correlations (R2) between the values of the simulated LAI and observed LAI in both years of the experiment were between 0.9 and 0.99.

Plant yield is a function of root distribution and its activity. Under limited water conditions, adequate root growth and efficiency are essential for crop productivity. To study the relationship between the dynamics of corn (Zea Maize L., variety single cross 704) root growth and soil available water uptake under drip-tape irrigation system, an experiment was conducted in a randomized complete block design with three replications. Experimental variables were three irrigation treatments including: 100% (I1), 80% (I2), and 60% (I3) of the actual plant water requirement calculated by the Penman–Monteith formula using meteorological data. The roots were collected from the beginning to the end of the growing season at four stages including: 25, 55, 85 and 115 days after planting. Samples were taken from 5 depths: 0-10, 10-20, 20-30, 30-40, and 40-50 cm. The results showed that irrigation treatments had significant effect (p=0.01) on root length density at different depths. About 60% of the corn root length density was up to the depth of 20 cm. On the other hand, the surface layers of the soil at this depth lost their moisture rapidly and, therefore, the plant needed to absorb water from the lower layers (below 20 cm) to survive. In low irrigation treatment (60% water requirement) up to the depth of 40 cm, root growth was low and, as a result, water absorption was also low. Higher irrigation had a positive effect on corn yield as the highest yield (7769 kg/ha) was obtained with the irrigation treatment of 100% water requirement.

In order to increase water use efficiency of Corn, a field experiment was carried out at the experimental farm of Agriculture and Natural Resources Research Center of Orzoueyeh located in Kerman province during the 2010 growing season using a completely randomized block design with three replications. Four irrigation treatments (net water requirement (control) and suctions of 1/2 FC, 1/5 FC and 1/8FC) were applied on single cross 704 cultivar. The results showed that water use volume were decreased in the three suction treatments of 1/2 FC, 1/5 FC and 1/8FC in comparison with control treatment, 11, 13 and 17 percent, respectively. While, the crop yield of the mentioned treatments reduced compared to the control, 4/5, 28 and 34 percent, respectively. However, water use efficiency was increased in the suction of 1/2 FC treatment compared to the control about 6/5 percent that shows the superiority of this treatment than other treatments. The weight of 1000 seeds, number of kernels on rows, number of rows of kernels on Ear in the suction of 1/2 FC treatment in comparison with control treatment were 5, 6.5 and 6.5 percent, respectively. Therefore, it appears that the application of deficit irrigation method for Corn cultivation in Orzoueyeh, Kerman can be a suitable way for saving water and increasing water use efficiency during drought periods.

Deficit irrigation is an effective method for alleviation of drought impacts and water usage reducing in drought period. Deficit (or regulated deficit) irrigation is one way to improve efficiency of water usage that crop is exposed to a certain level of water stress during a particular period.Therefore, in order to investigate the effect of deficit irrigation on yield and its attribute and water use efficiency of cotton under the terms of tape irrigation systems, a field experiment was carried out during 2010 growing season at experimental farm of Orzoueyeh Agriculture and Natural Resources Research Center in Kerman province. The treatments were laid out in split plot a Randomized Complete Block Design (RCBD) design with three replications. The treatments were comprised of three levels of irrigation including 100 (control), 80, 60 percent of crop water requirement in main plot and two irrigation systems as sub plot consisted of surface drip irrigation system (S1), subsurface drip irrigation system (S2). The results showed that In comparison with 100 percent of crop water requirement, 80 percent of water requirement caused parsimony of water usage equal 1500 m3 ha-1, and yield, number of bolls per plant and bolls weight decreased 12%, 11% and 2.5% respectively, but WUE was increased 5%. Also 60% of water requirement treatment compared with 100 % of water requirement caused parsimony of water usage equal 3200 m3 ha-1, and yield loss, number of bolls per plant and bolls weight decreased 38%, 37% and 24% respectively. The WUE amount is the same as it. Considering the results obtained in this study in the light of water saving as the main object in deficit irrigation and water use efficiency (WUE) for cotton cultivation in Orzoueyeh, the 80% of crop water requirement is preferred.

Limited water resources, shows the need for efficient use of water in agriculture. In this study to evaluate the impact of water rates based on soil moisture levels on yield of maize. Experiment was conducted in a split plot in randomized complete block design with three replications in Kerman Agriculture and Natural Resources Research Center (Jupar region) during 2008-2010. Four irrigation treatments were conducted including net crop water requirements (control treatment) and 3 treatments, of 1.2FC, 1.5FC and 1.8FC. The FC was measured using installed Tensiometer in each treatment. Irrigation interval in control treatment was calculated by FAO-Penman-Montheith model. The product yield, applied irrigation water, irrigation water consumption, water use efficiency, yield components and some measure of economic benefit to cost ratio were evaluated. Results showed the yield of maize was consistent with the reduced volume of irrigation. Accordingly, corn yield in control treatment was 8.5, 29 and 37 percent was higher compared to 1.2FC, 1.5FC and 1.8FC irrigation treatments, respectively. It is while, applied irrigation water increased 8.5, 13.5, and 17 percent compared to the control treatment. As a result, corn water use efficiency was equal in control and 1.2FC treatments. Irrigation frequency for the control treatment through was 2 days interval and that was obtained for other treatments based on Tensiometer monitoring and ranged from 3 to 8 days. Economic comparison confirmed superior control treatment and treatment 1.2FC compared to other treatments.

This research was carried out on corn in the Orzuiyeh region of Kerman province over twoconsecutive seasons (2005-6 to 2007-8). The experiment was done as a split plot with acompletely randomized block design and four replications. Four levels of consumed water(60%, 80%, 100% water requirement, water use based on regional custom) and three varieties (404SC, 700SC, 704SC) were the main factors and the sub-plots, respectively. The measured parameters included irrigation water volume, grain yield, and leaf area index. The results of the SWAP model indicated that a relatively good correlation existed between observation and calculated data, with irrigation treatment values being close to potential evapotranspiration.There were also significant differences between observation and calculated data for thevarieties. These differences were observed in values obtained for grain yield and leaf areaindex. In conclusion, the corn variety 704SC was more suitable than the other varieties forOrzuiyeh region. Considering the salinity of the water available for irrigation (EC = 4 dS/m2) in the region, 1100 mm per m2 of water was required to produce the highest relative grain yield. The results also showed a 7% decline in crop production for every increase of 2 dS/m2 in salinity.