Optimal irrigation scheduling requires to crop-water production function. Crop-water production function describes relationship between crop yield and applied water. A field study was conducted to compare various genotypes of wheat to water using line source sprinkler irrigation. The effect of variable water supply on yield, analysis of water production function with the seasonal rainfall, comparison of deficit and full irrigation strategies and crop coefficient (Kc) during the growth stage of six wheat genotypes were considered. Four locations where they were provided by the decline in irrigation with distance from the line source, during the growing season to meet 100 % (W1), 76 % (W2), 52 % (W3) and 39 % (W4) crop water requirement. The experiment used a strip plot design to examine the effect of the fixed irrigation rates on six cultivars treatments (CI=TAJAN, C2=N-80-6, C3=N-80-7, C4=N-80-19, C5=N-81-18, C6= Desconcido) with four replications.Within each irrigation treatment of each strip were divided into six cultivars treatments, along the length of the laterals. Result indicated that the grain yield was affected by irrigation treatment and cultivars. The maximum.grain yield was obtained in W1Cztreatment (4742 Kg/ha) and the minimum grain yield was obtained in W4C1 treatment (3546 Kg/ha).Investigation of water production functions have shown that under deficit irrigation, for 250 mm of seasonal rainfall with the same its distribution, there is no need to irrigation all of the cultivars.Contrary, in the full irrigation strategy, with 250 mm of seasonal rainfall, the cultivars of C1to C6need to 115, 122, 87, 94, 92 and 97 mm additional water as Supplementary irrigation to maximize production, respectively.The quantitative comparison of deficit and full irrigation strategies were showed that deficit irrigation was more useful strategy for obtaining more production as compared to full irrigation.

With the increasing population and the increase of food production, increasing production in rainfed fields is necessary for food security. With regard poor distribution of rainfall in recent years, water management for rainfed fields in critical conditions has priority. The results showed that for one or two irrigation in sensitive times, the yield of rainfed fields increased. Although Supplementary irrigation has been considered as yield improvement and water use efficiency in rainfed fields, study of special characteristics of rainfed fields, such as topography, slope, and the access to water resources is essential. The main purpose of this study is to evaluate the ability of supplemental irrigation in rainfed fields based on the topography and slope. According to the land use map of Qazvin province, about 284 thousand hectares are irrigated lands and 132 thousand hectares are rainfed fields in the province in which most of these lands are in the Qazvin plain. Then based on the slope map of the region, rainfed fields for doing Supplementary irrigation are classified into 4 classes: 0-5%, 5-8%, 8-12%, and more than 12%. The two land use and slope maps of Qazvin province were unified. In rainfed fields, 83, 10. 7, 3. 8, and 2. 5% of fields have slope 0-5, 5-8, 8-12, and more than 12%, respectively. So 97. 5% of rainfed fields have the ability to do Supplementary irrigation. Most of these lands are in the Qazvin plain and in the vicinity of irrigated lands.

This research was conducted to investigate the effect of Supplementary irrigation and frequency of irrigation (S) on yeild of three dryland wheat varities including Sardari, Sabalan and Glenson (V) on three replications at Tajrak Dryland Agriculture Research Center in Hamedan province, using Split Plot statistical plan. A non-irrigation treatment was considered as control one. Results of variance analysis indicated that Supplementary irrigation had a significant effect on grain yield, 1000 kernel weight, harvest index and spike number per plant. The variety type had a significant effect on the 1000 kernel weight and the spike number per plant. Supplementary irrigation in combination with variety type also had only a significant effect on the spike number per plant. The results of comparison of averages on the effects of Supplementary irrigation (S) at 5% level showed that S7 had a significant difference with the other treatments viewpoint the effect on various properties of yield. The results of comparison of averages on the effects of Supplementary irrigation in combination with variety (S×V) at 5 % level showed that S5V2, S7V2, S2V2 and S7V1 had the maximum of grain yield, straw yield, the spike number per plant and harvest index, respectively. Economical comparison showed that S2V1 treatment had maximum income, and so it is suggested to be used in similar conditions.

Introduction: Chickpea (Cicer arietinum L. ) is the most important field crop among the food legumes in Iran. According to the published statistic by agricultural ministry of Iran, about 90% of planting areas of chickpea is under dryland conditions. In Iran, chickpea is often cultivated in areas with limited rainfall or soil moisture and drought is always a potential problem for its production. From the importance issue, drought stress is the second abiotic stress that affect on chickpea yield. Also drought stress is the most important factor which reduces food legume crops production (especially chickpea, lentil and pea) under dryland conditions of west Mediterranean and North Africa regions. Limiting or cutting of regional rainfalls at the end growing season time and existing of drought damage in flowering time is one of the most important limitations in chickpea cultivation under dryland conditions that have highly negative effect on chickpea yield and reports show that, the yield of chickpea is low in these regions. Suitable field management for using from the existing water in order to reduce drought stress damages, increase the yields of crops under dry and semi dry regions. Results of studies show that, using from Supplementary irrigation in chickpea increase the total dry biomass, leaf area index, plant height and finally increase its yield under drylands. Also researchers reported that, flowering stage and pod filling period are the most important stages for application of Supplementary irrigation in order to reducing of drought severity in food legumes. Materials & Methods: This study was performed to evaluate the effects of Supplementary irrigation on some agronomic traits and grain yield of four chickpea genotypes. The experiment was conducted for three consecutive seasons during 2010-13 under field condition in Maragheh Dryland Agricultural Research Station (Latitude 37° 15′ N, Longitude 46° 15΄ E, and Altitude 1720 meter above sea level). The main plots were irrigation three-time (irrigation at planting, irrigation at planting and flowering times, and irrigation at planting, flowering and pod filling period). Each irrigation treatment included 40 mm water application in the experimental field. The sub plots were four Kabuli chickpea genotypes (Azad, Arman, ILC482 and a Turkish landrace from Van city). The soil of the experimental site is clay-lome, and the climate of the station is cold and semi drought with mean long term annual rainfall 360 mm, and with mean maximum and minimum absolute temperature about 37° C and-25° C in summer and winter, respectively. The mean annual air temperature in station is 9. 3° C. Each experimental plot was 6 planting rows with 6 meter length and 25 cm distance between two rows. Some agronomic traits such as number of days from planting to 50% of flowering and maturity, pod filling period, plant height, 100 seed weight, dry biomass, grain yield, harvest index and productivity score of genotypes were noted and analyzed by MSTAT-C program. The comparison of means method was Duncan’ s Multiple Range Test in 5% probability level. Results & Discussion: Combined analysis of variance showed that the year factor had significantly affected in all studied traits. The effect of irrigation times was significant on all traits except 100 seed weight, harvest index and productivity score. There were significantly differences among the genotypes in plant height, 100 seed weight, grain and dry biomass yields, harvest index and productivity score. The interaction of year×genotype significantly affected on all traits except plant height, dry biomass weight, harvest index and productivity score. Results showed that interaction effect of irrigation time by genotype was significant on seed and dry biomass yields. It shows that different studied genotypes had different responses to Supplementary irrigation times. The highest seed yield and dry biomass in all studied genotypes belonged to three-time irrigation. Azad cultivar seed yield under irrigation at planting time and flowering stage time was 1029 Kg. ha-1 that comparing with its yield under irrigation only at planting time (648 Kg. ha-1) increased about 58. 8%. It was the highest increasing in response among all studied genotypes for this treatment. The lowest response (increasing seed yield) under two-time irrigation (planting time+flowering time) belonged to Turkish landrace and was 28. 9%. In comparison of genotypes seed yields between one time irrigation treatment (irrigation at planting time) and three-time irrigation treatment (irrigation at planting+flowering and pod filling period) the highest and lowest increasing (71. 6% and 51. 3%) belonged to Arman cultivar and Turkish landrace, respectively. The interaction of year×irrigation time×genotype had not significantly effect on studied traits. The highest seed yield (1064 Kg. ha-1) belonged to the three times irrigation treatment. Among the studied genotypes, the highest seed yield (939 Kg. ha-1) belonged to ILC482. Conclusion: In conclusion and based on the results it would stated that, application of 40 mm irrigation increases grain yield and improve most of the agronomic traits in spring cultivation of chickpea crop under Maragheh dryland condition.

The objectives of this experiment was to study the effect of supplemented irrigation and chemical fertilizer application rainfed chickpea production. The experiment was implemented in a split split plots based on RCBD with 36 treatments and 3 replications at Sararood Dry land Research Station during 1991-1994. The supplemented irrigation as the main plot was provided at four levels of each with main irrigation water applicated preflowering (I1), rod initiative (I2) and seed development (I3), in the control (I0), no supplemented irrigation was given. In the subplots phosphorous and nitrogen fertilizer were given at four levels of P0, P30, P60 and NO, N20, N40 respectively. The results showed that supplemented irrigation increased grain yield through increase in biomass production and grain weight. This increase was 28, 40 and 56% at 11, 12 and 13 respectively. Supplementary irrigation at 13 had the highest effect on increasing the grain yield and for every mm irrigation water given then, there is 5.9 kg/ha. Increase in grain yield. phosphorous application did not have a significant effection the yield. The effect of nitrogen (N20) during 1994-1995 on grain yeild was significant. Therefore application of Supplementary irrigation along with 20 kg/ha nitrogen and no phosphorous is recommended for chickpea production in Sararood.

Rainwater harvesting (RWH) is one of the most effective water resources management techniques forconfrontation with water shortage condition. RWH which is basically known as a traditional method, has been developed rapidly and being used widely in dryland countries throughout the world. RWH is defined as collecting and storing rainwater from nearby catchment and delivering it to planting area during critical stages of plant requirement. RWH can be divided into two main categories which is known as micro and macro catchment methods. Many factors such as rainfall amount and distribution, ground topography, soil type, economical and social aspects are important for selecting a specific RWH category. In the present paper, design and performance of a real size macro catchment RWH project located in a semi arid region (N- E of Iran), is described. The project is comprised from a 5000 m2 plastic covered catchment, 500 m3 ground reservoir and an experimental cultivation area located next to runoff catchment which is planted with dryland wheat. Planting area is consisted of 8 scaled plots with dimension of 6m by 85 m. Following a randomized completely blocks design, four plots were considered for Supplementary irrigation and the rest four replications were accounted as control (without irrigation). In an effort to conserve more water, drip irrigation system was used with 4 lit /hr /m discharge capacity. The results of two years study indicated that, compared to the c onventional dry land farming undertaken in the control plots, wheat grain yield was increased by 70% and 87% respectively. During the study period, 35% and 70% of wheat water requirement was supplied from RWH system during plant growth period respectively. The result showed that it would be possible to have productive wheat cultivation in the regions with 250 mm annual precipitation (in average), if one can employ an effective RWH system.

Groundwater is a free water resource for agriculture. In this research two-year experiments from year 2009 to 2011 was conducted to find the percent of groundwater contribution in the presence of groundwater level with 80cm depth and two Supplementary irrigation procedure during flowering and both flowering and seedling conditions on three wheat cultivar namely W33g, Cross Alborz and Bahar in three replicate randomized complete block factorial experiments. Experiments performed at Razi university lysimeteric research station No1. Results showed a significant difference (P<0.05) between two Supplementary irrigation treatment. Also the highest groundwater contribution was found equal to 71.37% for treatment with one Supplementary irrigation during seedling period (for W33g cultivar) and the lowest groundwater contribution was found equal to 63.50% for treatments with two Supplementary irrigation (for Bahar cultivar) in the first year. The highest and lowest groundwater contribution equal to 76.86% (for Cross Alborz cultivar with seedling Supplementary irrigation treatment) and 66.40% (for W33g cultivar with two Supplementary irrigation treatment) was found in the second year respectively. Moreover, from point view of yield production, the highest value was obtained for W33g cultivar during both years of the study.

Supplementary irrigation in rainfed agriculture causes the increasing of crop yield and better using of water resources. The objective of this research was to investigate the effects of using of unconventional saline waters on Supplementary irrigation of rainfed barley. The treatments included a rainfed (D) treatment and four water salinity levels with EC of 0. 5 (S0), 6. 7 (S1), 8. 7 (S2) and 12 (S3) dS. m-1. When the barley grains filling, was performed the once spring irrigation based on deficiency of soil moisture. The yield amounts in D, S0, S1, S2 and S3 treatments were measured equal to 4005. 8, 6449. 08, 4918. 32, 4260. 08 and 3063. 72 kg. ha-1 (biomass yield), 1973. 18, 3174. 16, 2438. 48, 2112 and 1651. 32 kg. ha-1 (straw yield) and 2032. 62, 3227. 92, 2479. 84, 2148. 08 and 1412. 4 kg. ha-1 (grain yield), respectively. The results showed that for one dS. m-1 increasing of water salinity in Supplementary irrigation, biomass, straw and grain were decreased (relative to rainfed), equal to 7. 2%, 6. 7% and 7. 7%, respectively. Therefore, Supplementary irrigation of barley up to salinity level of S2, was recommended for rainfed cultivation conditions. Also, water productivity in D, S0, S1, S2 and S3 treatments were calculated equal to 1. 941, 2. 618, 2, 1. 73 and 1. 243 kg. m-3, respectively. Typically, water productivity in rainfed agriculture is more than irrigated crop cultivation. However, the results of this research showed that in Supplementary irrigation of barley up to salinity level of S1, the amount of water productivity will be more than rainfed cultivation conditions. Therefore, in addition of quality water, the using of saline water (at the crop tolerance level) for Supplementary irrigation of barley, causes the increasing of crop yield, food security and optimal management of water resources.