محمد خرمیان

The constraints of water resources and the imperative to enhance water efficiency in the production of vegetables and summer crops, on one hand, along with the economic importance of cucumber production in the country, on the other hand, reveal the necessity of investigating management indicators in cucumber production. The present study was conducted on a national scale with the objective of directly determining the applied water and water productivity indices in cucumber production fields across the country during a single crop year (1399-1400) in more than 180 selected farms, including about 70% of the cultivated area of cucumbers in the country. The results of the study revealed a highly significant disparity in various parameters among the selected provinces, including the volume of irrigation water, applied water (the sum of irrigation and effective precipitation), yield, and water productivity indices. The volume of applied water for cucumber cultivation exhibited notable variation, ranging from 4158 m3/ha in Hormozgan province to 8898 m3/ha in Razavi Khorasan province. The weighted average of applied water volume was calculated to be 7043 m3/ha. Similarly, the average yield of cucumbers displayed considerable diversity, ranging from 12750 Kg/ha in Zanjan province to 32956 Kg/ha in Razavi Khorasan province. The weighted average yield stood at 25219 Kg/ha. The calculated water productivity indices for both irrigation water and applied water were 4.27 Kg/m3 and 4.20 Kg/m3, respectively. Notably, the province with the lowest applied water productivity was Zanjan (2.21 Kg/m3), while the highest was observed in Fars province (6.59 Kg/m3). Based on the results, the total water requirement for cultivating cucumbers across an area of 55000 hectares in the country was estimated to be 330 MCM.

This study was conducted to evaluate the real cropping pattern of Khuzestan province in a normal water year (2018-2019) in terms of water withdrawal management from surface resources. For this purpose, the actual evapotranspiration of the products was calculated from the ratio of the available yield of different products (according to the agricultural statistics of 2018-2019) to the potential yield (the highest yield according to the agricultural statistics) by applying the country's water demand line system based on 10-year meteorological data. The results showed that the total water withdrawal from surface resources for the cultivated area of the crop year 2018-2019 (except greenhouses, livestock, poultry, and some products with a small area) was 18856 MCM, so the actual consumption (net irrigation requirement) was estimated 4310 MCM. Considering the Khuzestan Water Scarcity Adaptation Program, the total demand for agriculture and the environment with a confidence level of 80% in the Karun and Karkheh basins was 36 and 23.8% lower than the river flow, respectively, while it decreased to -72% in the Jarrahi basin, which indicated the failure to achieve the minimum environmental requirement. Since the Karkheh River flow has a more severe fluctuating behavior than that of Karun, this behavior cannot be predicted in the linear analysis of average values, and in droughts, it is less than the mentioned number. Therefore, dynamic planning in the field of cropping pattern change, providing various types of drought insurance, implementing infrastructure for the temporary purchase of water rights by the government, and other support policies are suggested in basins such as Karkheh, which has a highly fluctuating behavior in water supply.

The implementation of the Khuzestan Land reclamation Plan, has been provided a suitable platform to promoting research findings on the proper use of soil and water resources, agricultural inputs and increasing crop production. Therefore, this study was carried out in the agricultural year 2017-2018 with the aim of evaluating the water productivity resulting from improved management of canola production inputs and comparing it with conventional management in the northern lands of Khuzestan province. For this purpose, 11 farms (advanced management treatment) were selected to apply technical packages including irrigation scheduling, using the minimum tillage, applying balanced plant nutrition, raised bed planting, proper seed rate, according to farm conditions and farmer facilities. In each of these farms, the amount of applied water during the growing season, grain yield and water productivity were determined and compared with the surrounding farms data with traditional management (control treatment). The results showed that the average canola grain yield and water productivity increased from 2413 kg ha-1 and 0.51 kg m-3 in the control treatment to 2994 kg ha-1 and 0.69 kg m-3 in the superior treatment, respectively. This increase was statistically significant at the level of 1%.

Extension activities to improve irrigation and farm management will have an effective role in increasing yield and optimal use of water and soil resources. Yield gap is considered as one of the important issues in farm management, and it is very important to know the factors affecting it. One of the problems of farmers is their little knowledge in the field of water and soil. If they have access to modern knowledge and farm management, they can make an effective contribution in managing water use and increasing production. One of the solutions that can be effective in the field of optimal management of water consumption and other production inputs is to increase the knowledge, attitude and skills of farmers. The main goal of this research was to investigate and analyze the role of extension activities implemented in model sites located in the northern region of Khuzestan province in increasing yield and improving water productivity.

The intended extension method in this research was a model site based on which each model site has a main user and between 20 and 25 functional users. Functional units included farmers who, while visiting the main site, applied all or part of the recommendations used in the main site in their own farm.In order to transfer knowledge, increase yield and water productivity at on-farm scale, 52 extension model sites in the regions of Dezful, Shush, Shushtar and Andimshek located in the north of Khuzestan, Iran, (2017-2019) and in the technical packages (balanced nutrition, cultivation, optimal length of border irrigation, cultivar, low tillage methods, modified irrigation method) were done according to different crops. The crops were included wheat, corn, canola, sugarbeet, mung bean, onion, cabbage, lettuce, eggplant, beans and citrus fruits. In addition to model sites, control farms under traditional management were also investigated and evaluated. The result of comparing the average values of advanved management treatment (main site) and traditional management (control) was with t-test indicates the existence of a significant difference in yield and water productivity. Water productivity was obtained from the ratio of yield (kg/ha) to irrigation water. The guaranteed selling price of wheat, canola and sugar (beet) was 115 thousand rials, 235 thousand rials and 230 thousand rials, respectively. All measures in two parts of the farm were carried out by the operator under technical supervision and all measurements were carried out by the researcher.

The results of extension activities conducted by researchers and agricultural experts in the faremer condition and with the participation of 1201 of them, showed that if the results are widespread, the total amount of crop production will increase despite the reduction in irrigation water consumption. The amount of expected increase in the production of wheat, Canola, sugar beet, corn, mung bean and citrus fruits in Shush region was 14857 tons, 13347 tons, 8303 tons, 6225 tons, 221 tons and 870 tons respectively; The expected increase in the production of wheat, Canola and beans in Shushtar region was 19750 tons, 2028 tons and 83 tons, respectively; The expected increase in the production of wheat, Canola and beans in Shushtar region was 19750 tons, 2028 tons and 83 tons, respectively; The expected increase in wheat, corn and eggplant production in Andimshek region was 21966 tons, 3792 tons and 71 tons respectively and The expected increase in the production of wheat, Canola, sugar beet, corn, onion, lettuce, cabbage and citrus in Dezful region was 9447 tons, 20107 tons, 717 tons, 1594 tons, 2478 tons, 3610 tons, 5749 tons and 19232 tons respectively. The increase in water productivity by using specific technical packages for each crops compared to the control for wheat, canola, sugar beet, corn, vegetables, beans, mung bean, and citrus fruits is 10, 35, 9.6, 21.4, 42.5, 11.1, 50 and 168 percent respectively.

Considering the nature of the model sites, which is accompanied by the participation of the users in the processes of learning and applying techniques, the continuation of these activities can help the development and sustainability of the aforementioned achievements.

The North of Khuzestan province is one of the most important agricultural hubs of Iran. With the implementation of the Khuzestan Land Reclamation Plan (Provincial Plan), a suitable platform has been provided to increase field and horticulture crops production. Promoting research findings for proper applying of water resources, soil and agricultural inputs to increase water performance and productivity were the important goals of implementing model extension sites and pilots in these areas. For this purpose, 11 farms were selected in 2017, to apply technical recommendations. In each of the selected farms, the amount of irrigation water was measured during the cropping season, and the corn grain yield and physical irrigation water productivity were determined and compared with the data of the fields around each site (control treatment). The results showed that in the control treatment, the average grain corn yield and physical irrigation water productivity were 6450 kg ha-1 and 0.8 kg m-3, respectively, which by applying technical solutions of using the optimal length in furrow irrigation, reducing the inflow (cutback method), applying minimum tillage, management crop nutrition, pest management, pathogens and weeds increased to 7232 kg ha-1 and 1 kg m-3 and this increasing was statistically significant at 1% level (p=0.001).

This project was implemented with the aim of measuring water applied to onion under farmers’ management in 190 selected sites at the production hubs of onion in Iran including Azarbaijan Sharghi, Isfahan, Khusestan, Zanjan, Kerman, Fars, Khorasan Razavi, Khorasan Shomali, and Hormozgan provinces. According to the results, differences between the average volumes of irrigation water in those provinces, different irrigation methods, various sources and salinities of irrigation water and soil, and different onion varieties were significant (p<1%), during the growing season of 2020-2021. The average amount of applied water by farmers in those provinces was 9502, 13273, 9740, 16588, 9618, 13880, 11998, 8438 and 7057 m3/ha, respectively, with the weighted average of 10823 m3/ha. The onion yield in selected sites, varied from 20000 to 90000 kg/ha, with an average of 49980 kg/ha. The measured values were compared with the net irrigation water requirement estimated by the FAO Penman-Monteith method and with the National Water Document values. The results showed that the differences between average volumes of applied water by farmers, yield and irrigation water productivity, and irrigation water plus effective rainfall productivity in the selected sites were significant at 5% probability level. Irrigation water productivity varied from 3.13 to 6.30 kg/m3 and its average was 4.93 kg/m3. The average irrigation water plus effective rainfall productivity for onion in Iran was 4.50 kg/m3. The average net irrigation water requirement in the study areas by the Penman-Monteith method and the National Water Document were 8834 and 6972 m3/ha, respectively. These results showed that the average applied water in surface, sprinkler, and drip irrigation methods were 11453, 12740 and 10317 m3/ha, respectively, with significant (p<5%) difference. These results showed that in drip irrigation method, applied water was 10% lesser while irrigation water plus effective rainfall productivity was 35% higher. Transplanting seedling compared to direct seeding caused 14.7% reduction in applied water and 16.7% increase in water productivity. According to the results of this study, drip irrigation and transplanting method for onion fields is recommended.

Predicting crop yield is an important factor for efficient planning and management. In the present study, a simple mathematical model is developed for predicting the yield of autumn-sown sugar beet in Khuzestan region. In this model, the logistic function was used, in which the root yield and white sugar yield is defined as a function of irrigation, rainfall and evaporation from the pan. In order to evaluate the model, data of two-year trials conducted under five treatments of drip irrigation water based on percentage of water requirement (25, 50, 75, 100 and 125%) at Safiabad Agricultural Research and Education and Natural Resources Center, Dezful, were used. Results showed that the model was able to estimate root yield and white sugar yield with good accuracy so that the normalized root mean squares error (NRMSE) for estimating root yield in the calibration and validation stage were 9.4 and 13.0%, respectively. Also, the value of NRMSE for estimating white sugar yield in both calibration and validation years was less than 10% and equal to 6.8 and 9.8%, respectively. The model is able to have good accuracy during the growing season and estimate the values of root yield and sugar yield during different days after planting (DAP) with an error of less than 20%. Considering that the model presented in the current study is an experimental model, it is recommended to first recalibrate the model, and then use it in regions with different climatic conditions.

The present research was conducted to determine water stress tolerance and water productivity (WP) of 5 alfalfa cultivars as a split-plot design in a randomized complete block with 3 replications in the Safiabad Agriculture and Natural Resources Research Center (SARRC) with Silty clay loam soil texture during 2018-2019. The main plot was 4 levels of water irrigation depth (including 25, 50, 75, and 100% water requirement supply) with a constant irrigation cycle and the sub-plot was the five alfalfa cultivars (Baghdadi, Yazdi, Nikshahree, Omid, and Mesasirsa). Two-year data on forage yield and WP for six harvests (from June to November) were analyzed by SAS software. The results showed that the wet and dry forage yield decreased by applying water stress and the percentage of dry forage increased. The highest yield of dry matter (12.4 tons ha-1) and WP of dry forage (0.94 kg m-3) were obtained from 75% water requirement supply treatment. Baghdadi genotype with wet and dry forage yield 39.1 and 10.7 tons ha-1, respectively, and the WP of dry forage 0.9 kg m-3 was higher than other genotypes. However, the Yazdi genotype had the lowest yield of wet and dry forage (30.3 and 8.5 tons ha-1, respectively) and dry forage WP (0.75 kg m-3). Therefore, the Baghdadi genotype with a 75% water requirement supply is recommended for similar conditions to the climate of Northern Khuzestan to increase water productivity.

In order to evaluate the effect of methanol foliar application on yield and physiological traits of cowpea under water  deficit the experiments were carried out in the research farm of Safiabad Agricultural and Natural Resources, Research and Education (Dezful) along two crop years 2016-17 and 2017-18. The experiment was performed as split split plots in a randomized complete block design with three replications. The studied treatments included water stress at four levels (25, 50, 75 and 100% water supply of the plant) as the main plot, three levels of methanol foliar application (control, 10 and 20% by volume) as a secondary factor and two bean genotypes (1057 line omidbakhsh and Mashhad) were as a sub-factor. The results showed that the application of different levels of water stress reduces the relative water content of leaves, the amount of chlorophylls and carotenoids and increases the amount of electrolyte leakage and proline content. On the other hand, foliar application of different levels of methanol were able to reduce greatly the destructive effects of water  deficit so that the relative water content of leaf increased from 69% in control to 73% in 20% volumetric methanol. Also, 1057 line showed better conditions than Mashhad cultivar for all measured physiological traits and was better in ability to tolerate water deficit. In addition, harvest index and biological yield were reduced under water deficit condition, but grain yield at 50% water supply of the plant showed the highest value due to the earlier entry of the plant in this stress to the flowering stage and longer this stage compared to 75% and 100% water supply of the plant. Also, methanol foliar application was able to eliminate the destructive effects of water deficit on the measured yield traits.

Water resources limitation and plant stress due to water shortage is one of the important and common environmental stresses in agricultural production, including forage production in hot and dry areas. Therefore, the selection and development of drought-tolerant cultivars are very important. In irrigated lands of Iran, the average of irrigation efficiency is 37% and water productivity is 0.8 kg per cubic meters, which is lower than the world average. For increasing water efficiency, maintaining the production capacity and creating sustainable agriculture, it is necessary to identify the effective factors on the reduction of irrigation water productivity and provide an appropriate solution. In arid regions such as Khuzestan province, by using both a proper irrigation program and irrigation levels below the water requirement, obtaining the acceptable yield of alfalfa could be expected. In order to achieve these objectives, determination of the irrigation water productivity of tropical alfalfa cultivars and their drought tolerance under different irrigation regimes were the main aims of this study.

For evaluating tropical alfalfa genotypes under different drought stresses, an experiment was carried out based on split plots design with three replications in Safiabad Agricultural Research Center, Dezful, Iran, in 2019-2020. The main factor was four levels of irrigation (25, 50, 75 and 100% of water requirement) and the second factor was five alfalfa cultivars (Baghdadi, Nikshahri, Yazdi, Mesasirsa, and Omid). In this experiments, plant characteristics including dry and wet forage yield, percentage of dry forage, leaf to stem weight ratio, chlorophyll index (SPAD), electrolyte leakage from the leaf cell membrane (EL), relative leaf water content (RWC), and Maximum quantum yield in the dark-adapted conditions (ΦPSɪɪ) were determined.

The results showed that by applying drought stress, wet and dry forage yields, RWC, and ΦPSɪɪ were decreased but the percentage of dry forage, leaf to stem weight ratio, EL, and SPAD were increased. Among the studied genotypes, the Baghdadi genotype had the highest dry forage yield in all situations; non-stress conditions (16.9 t/ha), mild drought stress (15.094 t/ha), moderate drought stress (9.58 t/ha) and severe drought stress (4.664 t/ha). The Yazdi genotype had the lowest dry forage yield; 9.9, 9.7, 5.7 and 3.6 t/ha for non-stress, mild, moderate, and severe drought stresses conditions, respectively.

In our experiment, the Baghdadi genotype showed a high-stress tolerance index (STI) and we highly recommend planting it in the north of Khuzestan province, but the Yazdi alfalfa genotype despite low dry forage yield under both non-stress and drought stress conditions is not recommended due to low production. We suggest using Yazdi genotype in eugenic plans due to high yield stability index (YSI) under drought stress conditions and having some favorable physiological and photosynthetic parameters associated with drought stress tolerance.

Development of modern irrigation systems has been one of the main programs in developing agricultural sector in the past few decades. Assessing the role of these systems in increasing indicators of irrigation water management can play an important role in future national policies and planning. Therefore, this study was conducted with the aim of appraising water consumption management indicators in tomato production in different regions of Iran and evaluating the role of surface drip irrigation systems in increasing these indicators.

In this study, a field survey was conducted to measure yield and applied irrigation water of tomato under the farmers’ management in tomato production hubs. Volume of applied water by farmers in 176 farms in Fars, South Kerman, Hormozgan, Bushehr, Khorasan Razavi, Qazvin, Khuzestan, Golestan, Zanjan, Hamedan and Semnan provinces with different conditions of climates, irrigation methods (furrows and drip), salinity of irrigation water and soil; and different tomato cultivars were measured during growing season 2018-2019. The measured applied irrigation water values were compared with the net irrigation requirements estimated by the FAO Penman-Monteith method using meteorological data from the last 10 years, as well as the values of the national water document. Then, the effect of modern irrigation methods (surface drip irrigation) on applied water, application efficiency and physical water productivity was investigated in the study areas. Crop yield was recorded at the end of the growing season and water productivity (WP) was calcucated as the ratio of yield to total applied water (irrigation water and effective rainfall). Analysis of variance was used to investigate the possible difference between yield, applied water and WP among the hubs. Data adequacy was assessed by using the method provided by Sarmad et al. (2001).

The results showed that yield, applied irrigation water and WP in tomato production hubs were significantly different at the P ≤ 0.01. The average volume of applied irrigation water by the farmers was 7729 m3/ha. Water productivity in production areas varied from 4.33 to 9.52 kg/m3 and its average was 7.10 kg/m3. The average net irrigation requirement and irrigation application efficiency were 674 mm and 78%, respectively. Irrigation application efficiency obtained from the studied tomato farms was slightly higher than the average irrigation efficiency in Iran reported by Abbasi et al. (2016). Deficit irrigation was occurred in the fields of some areas such as Bushehr, Golestan and Semnan. Tomato planting time (spring or autumn) affected applied irrigation water, yield and WP. The volume of water used in autumn planted farms (5356 m3/ha) was less than spring planted farms (9831 m3/ha). The average yield of tomatoes in spring planted farms (74.3 t/ha) was significantly higher than the yield of fields planted in autumn (46.1 t/ha). However, the average of WP in spring planting farms (7.7 kg/m3) was higher than the productivity of farms planted in autumn (6.6 kg/m3). The application of surface drip irrigation systems in comparison with furrow irrigation resulted in 25% reducing in applied water, 10% increasing the application efficiency and 16% improving in water productivity.

In general, the results of this study provide useful information on applied irrigation water management indicators in tomato production to managers and water decision makers within Iran. Proper development and management of drip irrigation systems for row crops such as tomatoes and autumn planting of tomatoes in warm tomato production hubs is recommended for effective use of autumn rainfall. Also, training and application of methods to improve the performance of surface irrigation (using methods to reduce evaporation and the use of low pressure systems) is recommended to increase irrigation efficiency and reduce applied irrigation water.

North of Khuzestan province is one of the major areas for autumn sugar beet planting. Conventional tillage (CT) is widely practiced by sugar beet growers in this region. CT in sugar beet consists of burning wheat residue, using deep plowing with a moldboard plow or ripper plowing followed by several passes of disking, leveling, and furrowing. These aggressive tillage practices have many negative consequences for soils. Losses of soil organic carbon decreases soil permeability and consequently increases soil erosion and surface runoff. Therefore, applying conservation agriculture principles in sugar beet planting, conservation of residues and elimination or reduction of tillage, can help to optimize water use management and improve soil health on a farm scale. The objectives of this study were (i) to determine the possibility of direct planting of autumn sugar beet in wheat residues, (ii) to estimate sugar beet yield and crop water productivity (WP) under CT, chisel (CH), minimum tillage (MT) and no-tillage (NT) systems, (iii) to evaluate the response of sugar beet cultivars (Sharif and Palma) to different soil tillage systems, and (iv) to determine the effect of soil tillage systems on some soil physical properties.

A field experiment was conducted for two years (2016—2017) at the Safiabad Dezful Agricultural Research Center (32° 14.44´-32°15.93´ and 48° 25.41´-48°47). The soil of the study site was deep, well-drained with a silty clay loam texture. The mean annual precipitation and evaporation are 317 and 2400 mm, respectively, with an elevation of 108 m above mean sea level. Irrigation water was supplied from the Dez irrigation network without any salinity restrictions. The experimental was conducted in a split-plot arrangement based on a randomized complete block design with three replicates. The main-plot treatment was tillage method and the subplot treatment was two sugar beet cultivars (Palma and Sharif). Tillage treatments included conventional tillage (CT) (moldboard ploughing + MT steps), chisel (CH) (chisel ploughing + MT steps), minimum tillage (MT) (two perpendicular disks, fertilizing centrifugal machine, disking, furrowing, planting with pneumatic row planter), and no-tillage (NT) (spraying, planting with NT pneumatic row planter). The length and width of each plot were 100 and 6 m, respectively, and row spacing was 75 cm.Soil penetration resistance or cone index (CI) readings were recorded in 2 cm increments to a depth of 50 cm using SP1000 digital penetration tester to reflect the soil compaction. Soil bulk density was determined in 0-10 and 10-20 cm layers. In the first and second year, sugar beet samplings were done 216 and 220 days after planting, by harvesting a row of 75 cm with length of 10 m (7.5 m2). WP was calculated by dividing the root and sugar yield to irrigation water and effective rainfall (effective rainfall was calculated every year with SCS method). Composite data analysis and mean comparison were performed with MSTATC statistical software.

Results of CI showed no significant difference between four tillage methods at 0-10 cm depth. With increasing depth up to 30 cm, slight differences in soil compaction were observed for different tillage treatments, especially in the second year. Overall, compaction in the 0-50 cm profile in the CT and CH method were about 45% and 33%, respectively, lower than NT method, whereas in MT method it was about 37% higher than NT method. Results of root branch number analysis showed that the NT and CT treatments had the lowest branching (2.67 and 2.83, respectively) and the two CH and MT treatments had the highest branching (4.2 and 5.3, respectively). Therefore, NT had no negative effect on root growth of sugar beet. The results of bulk density measurements in the 0-10 cm layer were consistent with the results of the CI, but at depth of 10-20 cm, NT method with the highest bulk density (1.71 g cm-3) had significant difference with the other three tillage methods. Tillage method had no significant effect on root and sugar yield and root and sugar WP. However, in CT treatment, root yield increased by 6-8.5% and sugar yield by 6-12%, while root and sugar WP in NT treatment was about 8% higher than in the other three tillage treatments. On the other hand, changing climate conditions, especially rainfall during two years of the experiment, resulted in significant interaction between year and cultivar for yield and WP at 1% probability level. In the first year, the yield of Sharif cultivar (86.7 t ha-1) was higher than Palma (80.2 t ha-1), but in the second year, despite the decreasing yield of both cultivars, higher resistance of Palma cultivar to Cercospora disease resulted in a significant increase in sugar yield and WP over last year.

The two-year results of this study showed that the direct planting of autumn sugar beet in wheat residues (NT) is possible. Sugar beet yield and WP were not significantly different in tillage methods, but NT reduced tillage traffic from 7 times to 2 times and reduced energy consumption. The response of the two sugar beet cultivars to different tillage methods was the same and among them the Palma cultivar had the highest yield because of its higher resistance to Cercospora disease.

The aim of this study id analysis the effect of methanol foliar application on the physiological traits of beans genotype under water deficit stress as a split plot design was conducted in a randomized complete block design in Safiabad Dezful Agricultural Research and Natural Resources and Center in 2018 and 2019 years. Water deficit stress was the main plots include four levels (25, 50, 75 and 100% of plant water requirement) and combined foliar aplication of methanol including 3 levels (control, 10 and 20%) and genotype treatment including two cultivars omidbakhsh 1057 And Mashhad was in sub-plots. The results showed that the interaction of water deficit stress and foliar application of methanol on ion leakage, chlorophyll a, carotenoids, leaf soluble carbohydrates and proline grains was significant at the 1% probability level. The lowest amount of ionic leakage observed under the interaction of 100% water deficit stress and 10% foliar aplication of methanol (25/23 μmos/cm) and The highest amount of ion leakage under the interaction of 25% water deficit stress and the without foliar aplication of methanol (control) (42.25 μmos/cm). The highest amount of chlorophyll a was observed in line 1057 under the 100% water deficit stress and 20% foliar aplication of methanol (0.19 µmol.g-1 FW). The highest concentration of carotenoids in line 1057 under the treatment of 100% water deficit stress (0.19 µmol.g-1 FW) and the highest amount of soluble carbohydrates under the treatment of 100% water deficit stress and 20% foliar aplication of methanol (50.83 µmol.g-1 FW) was observed.

This study was conducted to evaluate the CWSI index in different cultivars of maize under drip irrigation Strategies at Safi Abad Agricultural Research Center, north of Khuzestan province. Irrigation management factors included T100 (100% water requirement), T75 (75% water requirement) and T50 (50% water requirement) were in main plots and maize hybrids including Single Cross 704 (SC), Mobin (M) and Karun (K) were subplots. High and low baseline relationships were estimated for all three cultivars with high accuracy (R2 <0.8) during the growing season. CWSI index varied from 0.01 to 0.46 for different treatments and at different growth stages. The results of statistical analysis showed that the difference of water stress index of maize was not significant between different cultivars but the effect of irrigation management on it was significant at 1% probability level. Accordingly, CWSI values of 0.17, 0.15, and 0.12 were estimated for corn growth and development, middle and end stages, respectively, to determine drip irrigation time using this index. In addition, the results showed that there was a high correlation between CWSI and maize yield and were derived the relationships to estimate yield by using this index. Based on these relationships, Caron hybrid had the highest sensitivityto water stress, with the coefficient or slope of grain and biological yield reduction against water stress were 21% and 47% respectively than were higher from other two cultivars.

Conservation tillage systems are recommended by government agencies around the world as an appropriate management option for preserving soil and water resources. Protective tillage has advantages over conventional tillage in terms of reducing energy consumption (Abbaspour et al., 2005). These include reducing erosion of water and wind (Lithourgidis et al., 2007), requiring less labor, increasing soil organic matter, and accelerating time of the second crop (Ito et al., 2007). Here, Manning’s roughness and penetration function are particularly important. More  accurate evaluation, design and simulation of these parameters provide better irrigation systems. If the parameters of the penetration equation are not close to the field conditions, irrigation may cause runoff and deep percolation. Kuotsu et al. (2014) studied the effects of different tillage on soil hydraulic properties and the productivity of rainfed land under rapeseed cultivation in northeastern India. The results of their research showed that infiltration and hydraulic conductivity significantly increased in conservation tillage systems, and the amount of water use efficiency (WUE) was the highest in the conservation tillage system. Considering the necessity of protecting the soil and water resources and the important role of tillage operations, this research investigated the effects of different tillage methods on the hydraulic properties of barley surface irrigation using WinSRFR model.

This research is based on the results of a study that was carried out to evaluate the effect of direct drilling of wheat in maize residues on yield and water productivity (WP) for two years of 2016 and 2017. For this purpose, a field experiment was conducted as split plots with a randomized complete block design with three replications in Safiabad Agricultural Research Center located in Dezful, north of Khuzestan province. The main plot treatments were including: No-Tillage (NT), Minimum Tillage (MT), and Conventional Tillage (CT) and sub plots treatments were Chamran 2, Mehregan, Shoosh, Falat, and Darab 2 cultivars. The results showed although there was no significant difference between tillage methods, but the average yield of cultivars in the NT (4830 kg ha-1) was more than the MT (4610 kg ha-1) and CT (4680 kg ha-1). On the other hand, the average yield and WP of both Mehregan and Chamran2 cultivars (5000 kg ha-1 and 1.25 kg m-3,respectively) were more than the other cultivars. Although in this research, reducing passes of tillage and planting machinery from 6 to 7 times in MT and CT to only 2 times in NT method (chemigation and planting in maize residues) did not have a significant effect on the soil cone index and soil bulk density, the soil organic carbon increased 16 to 32 percent in NT method in comparison to other tillage methods. Therefore, the use of new wheat cultivars under direct drill planting conditions in maize residues without yield reduction and 3-4 percent WP improvement is recommended in similar areas.

Despite the importance of determining and measuring the indices of irrigation water management in the agricultural sector for application in macroeconomic planning, these indices have not yet been done in modern and conventional irrigation networks. Therefore, the present study was conducted to compare the indices of irrigation water management (water consumed, water productivity and water application efficiency) in modern and conventional irrigation networks producing silage maize in Iran. The data were obtained by direct measurements from fields in the provinces of Alborz, Tehran, Fars, Khuzestan, Khorasan Razavi, Ardebil, Isfahan and Qazvin, which covered about 70% of areas under cultivation of silage maize in Iran, in more than 100 farms in modern and conventional irrigation networks. Results showed that the differences in water consumption and water productivity indices of modern and conventional irrigation networks were statistically significant to produce silage maize. Consequently, the yield of silage maize measured 50.54 and 54.32 ton ha-1, water consumption measured 6983 and 9085 m3 ha-1 ,water productivity measured 7.46 and 6.26 kg m-3, and water application efficiency measured 73% and 68% under the modern and conventional networks, respectively. These findings indicate that development of modern irrigation networks can promote water productivity and are valuable to be applied in the five-year national development plan and economic programs.

Khouzestan province with about 1000 hectares of seed clover is the most important region for seed production of berseem clover (Trifolium alexandrinum) in Iran. Extending the cultivation area of berseem clover (BC) is important due to the favorable effects of BC on soil fertility and the necessity of this region to a desirable crop rotation. The harvest date of summer crops such as corn leads to delay in optimum sowing date of BC. Several investigators in other areas have demonstrated that early sowing dates improved yield of BC. On the other hand, the most important factor in crop yields is water irrigation; it plays an important role in sustainable agriculture. Based on the existing literature, early sowing date reduces the number of irrigation events and increases water irrigation use efficiency (IWUE). Therefore, this experiment was conducted to evaluate the response of spring BC sowing date and last irrigation cutoff time on seed yield and IWUE. This study was carried out in Safiabad Agricultural Research Center in two years (2014-15). Soil texture of the experimental field was silty clay loam, well drained without salinity (ECe=1.2ds m-1), with 0.75 percent organic carbon. The statistical design of the experiment was split plot based on a randomized complete block design with four replications. The main plots were allocated to sowing date including 10th Feb, 20th Feb, 2st Mar and 12th Mar, and the sub plots were assigned to irrigation cutoff dates including 5th Jun, 15th Jun and 25th Jun. Daily evaporation from class A evaporation pan of the Safiabad weather station (nearby the experimental field) was measured to calculate water irrigation depth, and BC evapotranspiration was calculated by applying a pan coefficient of 0.8. Irrigation interval was managed based on 80 mm accumulated evaporation from the pan evaporation. The measured traits included seed yield, IWUE, number of seeds per inflorescence (NSI), number of inflorescences per square meter (NI), days to flowering, straw production, total dry matter (TDM), harvest index (HI) and weighed a thousand seeds. There was a significant difference between the irrigation cutoff date for all traits except the number of days to flowering and HI. The results of the mean comparison showed that the, sowing date of 20th Feb and irrigation cutoff in 15th Jun, with seed yield (631 kg.ha-1) and IWUE (0.72 kg.m-3) was better than the other treatments. In this treatment, the plant growth period in the first sowing date (88.6 days), and the NI (623 numbers), and the NSI (37.1 numbers) was higher than the other treatments. The correlation between seed yield and other traits was positive and the stepwise regression analysis showed a positive and high effect of NI on seed yield in BC. The results of this trial confirm previous findings that BC early sowing dates, will had higher seed yield. Also, the results showed that delaying in irrigation cutoff is effective in decreasing IWUE, so that irrigation until 25 th  June in comparison with 15 th June, In spite of significant increasing in yield, decreased IWUE significantly.

In order to evaluate the effect of potassium sulfate nutrition on chlorophyll contentand drought tolerance indexon Mungbean genotypes in the north of Khuzestan Province, this study was conducted in split plot factorial in a randomized complete block design with three replications in 1390 and 1391 at the agricultural Research center south of west Country (Safiabad). The main plot was irrigation after 120, 180 and 240 mm evaporation from pan evaporation (respectively marked I120, I180 and I240),and the subplots were potassium fertilizers with 0, 37.5 and 75 kg K2O per hectarfrom potassium sulfate(respectively marked F0,F1 and F2) and genotypes (Parto, Hindi and VC6173, Cn95 and KPS1lines ) in a factorial arrangement.The results showed that grain yield in I180 and I240 treatments, reduced 21.8 and 30.4 percent respectively in comparison with control treatment(I120).the highest and lowest tolerance to drought stress were allocated to Hindi (0.83) and KPS1 (0.47) respectively. Potassium application at the rate of 75 kg/ha in I240 treatment, increased drought tolerance in all genotypes except KPS1. chlorophyllcontent was influenced irrigation regimes, irrigation and genotype, irrigation-fertilizer as well as the interaction of three factors at the of 1% and fertilizer and genotypes at the level of 5%.The overall results showed that Hindi due to high drought tolerance and VC6173 due to shoot standing and high drought tolerance were superior to other varities.

Watermelon is one of the most important profitable vegetables in Khuzestan. A mild water stress helps watermelon to develop the root system. Water stress has a negative effect on the yield of watermelon but it increases the quality of the fruit. Watermelon is usually planted in mid-June and is irrigated in a furrow irrigation which, generally, has low application efficiency. The high amount of water consumption, especially in the early stages of growth, requires considering the drip irrigation method. Recently, using drip (tape) irrigation has become more common in Khuzestan. However, there is not enough information regarding the impact of pressurized irrigation systems on the performance of watermelon varieties. Therefore, the current research was conducted with the aim of evaluating tape irrigation levels on watermelon varieties in Northern Khouzestan.

For optimization autumn sugarbeet irrigation water, an experiment was conducted at Safi-Abad Agricultural Research center in the years 2010 and 2011 with silty clay loam soil.The experiment was arranged in randomized complete blocks design with three replications. Tape irrigation levels (25,50,75,100 and 125% of water requirement with T25,T50,T75,T100 and T125 respectively) and furrow irrigation was conducted. Production, cost and water function and thresholds indexes basis of irrigation depth was compared and computed. Although full rrigation in field experiment(T100 treatment) and maximizing level of applied water index(Wm) had maximum yield, T100 treatment had not significant difference with T75 and T50 treatments. On the other hand irrigation water application depth in water limited condition (Ww) was almost equal to minimum rate of water application,T25 treatment. Although Ww index had not maximum net benefit per unit of irrigation water, caused to decrease 43 percent consumed water and 21 percent of root yield and caused to increase sugare content and decrease irrigation costs. The results showed that in a view economic deficit irrigation in North of Khouzestan climatic conditions was applicable.

The area cultivated for wheat is about 550000 ha in Khuzestan province. Limited rainfall conditions and incompatibility of rainfall patterns with wheat crop requirements leads to decreasing of soil moisture and drought stress. Studies have shown that water supply affects the uptake of nutrients and nutrient use effeciency. On the other hand, the benefical effect of the application of zinc and potash nutrients under different water stress in Khouzestan is not convenient for farmers. Therefore, this study aimed to determine the effect of drought stress and zinc and potash in silty clay loam soil on yield and water use efficiency (WUE) of wheat.
The experiment was carried out in Safiabad Agricultural Research Center (SARC) of Dezful, Khuzestan during the years of 2008-09 and 2009-10. Before the experiment, initial composite soil samples (0-30 cm & 30-60cm depth) were collected from the experimental plots and were analyzed. The soil was silty clay loam with low organic matter content (OC=0.5-0.75%) and well drained without salinity (ECe=0.27-1.3 ds m-1). On the other hand, micronutrient content of the soil (Fe, Mn and Cu) was higher than the threshold limit. The design was a split plot on a completely randomized block design with three replications. The main plot consisted of three different levels irrigation after 50 (I50), 75 (I75), and 100 mm (I100) evaporation from evaporation pan and sub plots included three levels of fertilizers, without micronutrient (F0), fertilizing based on soil analysis value (F1), and fertilizing basesd on 1.5 times more than the recommended level (F2). Every subplot size was 3.6 m x 10m. The studied cultivar was Chamran and the sowing date was on November with a density of 400 seeds per m-2 and harvested during May in both growing seasons. Soil moisture content was measured before every irrigation in root zone depth using the weighning method. Applied water was measured using flow meter for every treatment. After seed ripening, grain yield per hectare and component yield were measured from the total area of each treatment. Statistical analysis was performed using MSTATC software packages and mean comparison was also performed using Duncan’s Multiple Range Test (DMRT).
The rainfall during plant growth for first and second years was 68 and 221 mm respectively. The mean temperature of Mars and April in the seconed year was 26.1 and 34°C increasing by about 1.4 and 1.9°C compared to the first year. The higher temperature in the second year increased heat stress which led to yield decrease. Irrigation water consumptions in first year for I50, I75, and I100 treatment were 960.6, 804.1 and 682.2 mm and in the second year 182,115 and 95 mm respectively. Higher rainfall in the second year in comparison with the first year led to decrease in number of irrigation events. All the studied parameters except for 1000-grains weight and number of grains per spike were significantly influenced by different levels of fertilizer treatments.The highest yield belonged to fertilizing based on soil test results (F1), (40 kg K per ha, Zinc Sulfat with 200 kg per ha potash) while the lowest yield was found in the control treatment(F0). Cakmak et al. (1996) and Yilmaz et al.(1997) also observed similar responses. A similar trend was observed in the biological yield, number of spike and 1000-grains weight. Increasing rates of K and zinc(up to 40 kg.ha-1) increased the values of crop parameters such as biological yield, number of spike , 1000-grains weight and water use efficiency and thereafter higher levels of K and zinc fertilizer (F2 treatment) led to their decline. Analysis of variance on yield showed that irrigation regime, potash and zinc fertilizer levels were significantly different (pThe overall results from this study indicated that it is essential to avoid applying potash and zinc fertilizers over recommended values in soil under moisture stress conditions. Intraction between different irrigation levels in combination with fertilizer showed that I75F1 with yield and WUE, of 6.4 t ha-1 and 1.28 kg m-3 respectively could be recommended.

The soil hydraulic conductivity (Ks) is very important parameters in soil physic and the designing of drainage systems. In this study the basic infiltration rate, infiltration rate and the saturated and unsaturated soil hydraulic conductivity were determined in a randomized complete block design with three treatments and three replications in a corn field in north of Khuzestan (Dezful) in 2013. The treatments were including No Tillage (NT), Minimum Tillage (MT) and conventional Tillage (CT) methods. In order to compare the effect of mesearing method of saturated hydraulic conductivity with two methods of double rings and disc permeameter on tillage methods the factorial test were used. The messuring of disc permeameter was performed in 15, 10, 5, 3, zero suctions. The results showed that the basic infiltration rate, infiltration rate and saturated and unsaturated (exept 10 and 15 suctions) hydraulic conductivity in CT method were significantly higher than the other methods of tillage (P