جستجوی مقالات مرتبط با کلیدواژه « اجزای عملکرد » در نشریات گروه « آب و خاک »

To evaluate the effect of different irrigation methods on yield and water use efficiency (WUE) of chitti beans, a research study was conducted in 2022 and 2023 at the Bean Research and Education Center in Khomein, Iran. The study was designed as a multi-location (regional) experiment using a randomized complete block design with three replications. Four irrigation methods included classical sprinkler irrigation, New-fit sprinkler irrigation, rain flat irrigation, and drip tape irrigation. Different types of chitti bean cultivars (line 21492, Kousha, and Saleh) with three growth habits were randomly sown in these locations. The results showed that the maximum water consumption (12500 m3 ha-1) belonged to the classical sprinkler irrigation method, while the least (6600 m3 ha-1) was in the drip tape irrigation; and the New-fit sprinkler and Rain flat irrigation had almost the same water consumption (about 11000 m3 ha-1), were in between those two methods. Also, the highest and lowest WUE (0.45 and 0.18 kg m-3, respectively) were obtained in drip tape and classical sprinkler irrigation, respectively. The results of analysis variance showed that the irrigation method effect on yield components and grain yield was significant, but the effect of cultivar was significant only on grain yield. The highest (296.9 g m-2) and the least (228.7 g m-2) values of grain yield were observed in the drip tape and classical sprinkler, respectively. Among the cultivars, the highest grain yield belonged to Kousha and Saleh cultivars. In general, the results demonstrated that the drip tape not only decreased water consumption but also led to improving yield components of chitti bean and higher water use efficiency.

Due to the limited quality of water resources and considering that the majority of the country is arid and semi-arid, it is important to cultivate plants with a high tolerance to drought and salinity. This research was conducted to determine the effect of different moisture levels on yield and yield components of quinoa (Chenopodium quinoa Willd.) under lysimetric conditions in the spring and autumn cropping seasons. Treatments included irrigation after draining 0.2, 0.4, 0.6, and 0.8 of the total available water (TAW). Irrigation was done based on the soil moisture depletion and the leaching requirement of about 20%. At the end, dry biomass, seed yield, and yield components were measured. The results showed that with an increase in the moisture depletion from 0.6 to 0.8 TAW, the biomass and seed yield had a significant decrease of 24 and 37% in the spring and 34 and 47% in the autumn cropping season, respectively. But the increase in moisture depletion from 0.2 to 0.4 and 0.4 to 0.6 did not cause a significant decrease in these traits. The results indicated that changes in moisture depletion levels caused significant differences in plant height (P<0.01), stem diameter, and 1000-seed weight (P<0.05) in spring cropping, but their effect on panicle length and width and the number of secondary stems was not significant. In the autumn cropping season, the results showed that changes in moisture levels caused significant differences in plant height and the 1000-seed weight (P<0.01), but the effect on other yield components was not significant.

Corn is one of the most widely consumed cereals in the world, which is highly compatible with many climates. For this reason, corn has been cultivated in most regions of the world since ancient times. Therefore, it is also considered a part of people's food all over the world. The effect of nitrogen fertilizer, as an agricultural solution, on the growth and yield of corn has caused it to be split to increase the plant's access time to this nitrogen source. In fact, due to the leaching of nitrogen fertilizer, it is usually not applied in one step. For this reason, based on the prevailing conditions of the field, the operators divide it into two or more divisions and perform nitrogen fertilization during the growth period. In each division, it is necessary to determine and apply the optimal amount of nitrogen fertilizer in order to minimize environmental pollution in addition to being economical. It requires many field experiments, which require a lot of time and money. To solve this problem, the use of simulation and optimization models, such as response-surface modeling, is suggested. The response-surface method is one of the suitable optimization tools that has been considered in various sciences for many years. The statistical basis of this method is very complex and uses a multi-objective nonlinear model for optimization and modeling. The response-surface method first provides a suitable combination of treatments, and by considering them, a statistical model is created that has the best fit compared to other models. Next, the most optimal value is determined for the independent variables so that the value of the dependent variables reached their maximum or minimum.

For this purpose, the data collected from a research project, which was carried out in the 500-hectare farm of the Seedling and Seed Research Institute in two years (2011-2012), were used. Two factors consisted of fertilizer in three levels (N1: 100 and N2: 60% and N3: 50% of fertilizer requirement) and the time of splitting into three methods (T1: the farmer's application with two splittings; T2: three equal divisions and T3: four equal divisions) was considered. The response surface method was used to optimize yield and yield components. In the response-surface method, the code of -1, 0, and +1 for nitrogen indicates 50, 60, and 100 kg/ha of nitrogen fertilizer, respectively. The code of -1, 0, and +1 for fertilizer splitting indicates the number of 2, 3, and 4 nitrogen fertilizer splitting during the growing season, respectively. In this method, to fit the data, multivariate regression was used by adding linear terms, quadratic, and interaction between factors. Then, regression was evaluated based on the analysis of variance. The statistical criteria used included root mean square error (RMSE), normalized root mean square error (NRMSE), mean bias error (MBE), model efficiency (EF), index of agreement (d), and coefficient of explanation (R2).

The results of ANOVA showed that the linear and quadratic regression model for seed yield and the linear regression model for fertilizer efficiency was significant at the 5 % probability level (P-value ≤ 0.05). For water productivity, the splitting factor had a greater effect on the regression than the amount of fertilizer, although both factors did not show a significant effect. The regression model had a significant effect on the 1000 seed weight, number of seeds in a row, number of rows in a cob, cob length, and seed size. The regression of other variables was not statistically significant. Therefore, the response-surface method can be used to predict and optimize variables with significant regression. The results showed that the regression model was capable of predicting variables including 1000 seed weight, number of seeds in a row, number of rows in a cob, corn length, and seed zinc content. But this model had an underestimation error (MBE ≤ 0.0) for all variables. The accuracy of the regression model for grain zinc content was in a good category (0.1 < NRMSE < 0.2) and for other variables in the excellent category (0.0 <NRMSE< 0.1). By increasing the amount of fertilizer (changing from code -1 to + 1), the yield initially decreased and then increased. With the increase of fertilizer splitting, corn yield decreased first and then increased. The effect of the amount and splitting of fertilizer on changes in the 1000 seed weight was linear and with the increase of these two factors, the 1000 seed weight also increased. This result was also observed for the number of seeds in the cob. In terms of cob length and grain zinc percentage, the two factors of fertilizer amount and splitting had similar effects on the increase of these two variables, but at low values of both factors, the mentioned variables decreased slightly. Increasing the amount and distribution of fertilizer caused an increase in the number of rows in the cob, but high amounts of these two factors had no effect on the increase in the number of rows in the cob. Except for the number of rows, other variables increased along with increasing the amount of fertilizer and its splitting. Providing 100% fertilizer requirement and increasing the number of divisions to 5 times, can increase maize yield by up to 1.5 tons per hectare. This was about 28% of the average yield and 6 % of the maximum corn yield in this study. The weight of the thousand seeds increased to 3.5 grams under optimal conditions, which increased by 32 and 9 % compared to the average and maximum values in this study, respectively. The variable of the row was not much of a change in the average variable (1.5 cm) and increased by only 1 %. The optimal length increased to 3.5 cm and the optimal rate increased to 62%.

In general, the optimization results of all variables showed that if the fertilizer requirement is applied as N1 and in five splittings; the amount of yield, 1000 seed weight, the number of seeds in a row, the length of the cob and the amount of seed will increase by 6, 9, 12, 18.5, and 19.6% respectively compared to the maximum values of these variables. Therefore, it is suggested to apply this scenario in the field to improve yield and yield criteria such as zinc concentration in corn seeds.

Drought and water shortage in Iran is a climatic fact and due to the growing need for water in different sectors, this problem will become more acute in the coming years. Therefore, managing water consumption and applying advanced techniques in the agricultural sector as the largest consumer of water in the country, can be very helpful. One of the most effective strategies to improve water productivity in agricultural sector is to use hydrogel polymers to improve soil texture, increase soil water retention, reduce erosion and increase germination (Nirmala and Guvvali, 2019). However, in general, due to differences in the synthesis and chemical structure of polymers, the water uptake and storage capacity of these hydrophilic polymers are different, and hence their effect on changes in soil moisture and storage capacity will be very different (Yu et al ., 2017). The aim of this study was to investigate the effect of different levels of Aquasource hydrogel on yield, yield components and water productivity of peppermint (Mentha piperita) at different irrigation intervals.

Water crisis is one of the most important problems in arid and semi-arid areas such as Iran. Also, in these areas indiscriminate use of nitrogen fertilizer have had severe environmental consequences. Thus, assessment of plant responses to water stress, the amount of nitrogen and, estimation of production function for determining optimal use of water and fertilizer is inevitable. The objective of this study was to investigate the interrelations of yield, irrigation depth and, applied nitrogen fertilizer of Radish (Raphanus sativus L.). For this purpose, the study was conducted in the College of Aburaihan (Southeast Tehran, Pakdasht, Iran) in 2020. Experiment was arranged based on randomized complete block design with two treatments of nitrogen fertilizer and irrigation water depths with three replications. In this study the Levels of irrigation depth were 120% (I1), 100%(I2), 80%(I3) and 60%(I4) of irrigation requirement the levels of applied nitrogen fertilizer were 120%(N1), 100%(N2), 80%(N3) and, 60%(N4) of nitrogen use requirement. In this study four equations of of linear, Cobb-Douglas, quadratic and transcendental were used to determine the water-nitrogen production function production. The results showed that the quadratic equation simulates the dry yield of radish with a higher accuracy. The results showed also, the I3 (142 mm) and N2 nitrogen (150 Kg per hectare) treatments, were yielded the highest yield and irrigation water use efficiency.

Increasing demand for water for irrigation in the agricultural sector has led to increasing reuse of treated or raw municipal and industrial effluents in many countries around the world. The use of wastewater is usually associated with microbial contamination and heavy metals that affect various parts of nature and therefore human health. Heavy metals in these unconventional waters are one of the sources of water, soil, and plant pollution that the toxicity of heavy metals in plants reduces plant growth. The above problems can be solved by modifying water and soil magnetically. In this study, the effect of using treated magnetic effluent on the yield components of maize plants was investigated. For this purpose, a factorial experiment was conducted in a randomized complete block design with three replications in 2020 at Babolsar city. Treatments include irrigation with well water (W1), irrigation with mixing 25% of effluent and 75% of well water (W2), irrigation with the mixing of 50% of effluent and 50% of well water (W3), irrigation with mixing of 75% of effluent and 25% of water Well (W4), irrigation with 100% effluent (W5) under magnetic field (I1) and without magnetic field (I2) was. Irrigation water magnetization was created by passing water through a permanent magnet with a magnetic field intensity of 0.3 Tesla. The results showed that the effect of irrigation type and water and effluent mixing on fresh and dry mass weight, number of seeds per corn, 1000-seed weight, biological yield, and grain yield were significant. On average, irrigation with magnetic effluent significantly increased grain yield (9.18%) and biological yield of maize (10.09%) compared to non-magnetic effluent. Yield and yield components of maize also increased with increasing effluent use. In general, by using magnetic technology, unconventional waters can be used and the amount of plant yield can be increased.

The arable land in Iran is about 11 million hectares, and maize production is the second largest after wheat production. Agricultural studies in Iran lands reveal that the water use efficiency of irrigation is between 22.5% and 85.5% with an average of 56%. Drip irrigation is one of the best methods that by applying appropriate management can be used for agriculture in high salinity soils, with saline irrigating water and dry conditions, especially for maize crops. Sprinkler irrigation system has a positive effect on improving irrigation efficiency in Iran, but the main problem of this system is the water loss related to evaporation and wind. Usually, drip irrigation plan is implemented in combination with sprinkler or low-pressure irrigation plan, so that it is possible to change the irrigation network and make an optimal use of the system according to the needs of the cultivation pattern. In the most previous studies, drip irrigation tape was generally used, depending on the type of crop and the growing conditions. Also, limited studies have been conducted on the comparison of irrigation tape types, hence comprehensive studies are needed. Also, study on the interactions of different types of tapes and irrigation levels is needed. The aim of this study was to evaluate the performance and yield components of forage maize under moisture stress. A pilot project was conducted in form of factorial experiment of randomized complete blocks, during one year in Isfahan province. There were 6 treatments consist of emitter tape systems of 15, 20, and 30 cm, and drip tape of 10, 20, and 30 cm with distance of 0.7 m. The treatments of irrigation included 5 levels of 100, 90, 80, 70 and 60% of soil moisture depletion, with 3 replications. The cultivated maize cultivar was Single Cross 704, which was cultivated at 0.7 m intervals. For each treatment repetition of three rows of the same irrigation strip with the length of 50 m was performed. The crops were harvested from the middle row. During the growing season, irrigation was carried out for 22 times based on the measurement of moisture in the root zone and the supply of moisture deficiency to the level of crop capacity in terms of programmed water shortage. For each treatment-repetition, amounts of total product weight, total weight of maize, average plant height, average height of maize, product productivity index and maize productivity index per hectare were calculated at the end of the cultivation season after sampling. The results showed that the main and interaction effects of irrigation tape type and irrigation rate on yield components were significant at 1% probability level. Based on the performance indicators, the best treatment was the emitter tape strip with the 20 cm nozzle-distance, the total crop yield and maize yield of 70112 and 14593 kg/ha, respectively. According to the product performance index, the emitter tape with the diameter of 30 cm and the drip-tape of 30 cm, were the weakest treatments in terms of maize's performance. Wetting widths in heavy-textured soils are wider than in the light-textured soils. Despite the relatively heavy texture in this study, the 30-cm distance between the nozzles in the irrigation strip did not provide adequate overlap in the development of moisture within the plant root zone. Therefore, the irrigation tape with the nozzle distance of 30 cm is not recommended for the cultivation of forage maize in similar conditions of the present field. In terms of irrigation levels, the best result obtained in the treatment of 100% depletion of the moisture capacity of the root area with crop yield and maize yield was 66.5 tons per hectare and 11.3 tons per hectare, respectively. According to the two indicators of plant and maize height, the drip-tape irrigation strip next to the seam with the nozzle distance of 20 cm (with plant and maize height of 19.15 and 19.4 cm, respectively) as well as the 15-cm emitter tape were in the top group. The weakest treatment according to these two indicators was the 30-cm drip tape and then the 30-cm emitter tape treatment. A comparison based on irrigation levels showed that the treatment supply of 100% depletion of moisture capacity of root zone was the superior treatment with the plant and maize height of 179.3 and 15.3 cm, respectively. Also, in terms of maize's height, there is no significant difference between the treatments of 80%, 90% and 100. In terms of water efficiency indicators, the 20-cm drip tape was the best option with crop and crop water productivity of 13.4 and 2.8 kg/m3, respectively. The highest water productivity for the total product and maize occurred in the treatment of 100% and the lowest in the treatment of 60%. Based on the interaction of irrigation tape types and irrigation levels, the superior treatments was that in which the drip tape by 20 cm was applied, 100% of soil moisture was provided, forage yield and water productivity of 81279 kg / ha and 14.2 kg / m3 were obtained, respectively.

In order to evaluate the performance of sub-irrigation system using porous clay capsules, the experiment was conducted as factorial plot in base of randomized complete block design with three replications and two irrigation treatments on two different time, 21-MAY-2016 and 21-JUNE-2016 for rice culture. In this study some morphological traits including grain yield, number of empty seeds, number of filled seeds, number of whole seeds, weight of main panicle, main panicle length, 1000-grain weight, plant height, water consumption and water use efficiency were assessed. The results showed that flooding irrigation had no significant effect on the yield increasing compared to sub-irrigation at two sowing dates. Also, the water consumption decreased 30% and 39.5% using sub-irrigation in two sowing date (21-MAY-2016, and 21-JUNE-2016) respectively, comparision to flooding irrigation. Based on the result grain yield at two sowing date had significant effect. The grain yield decreased 28 percent in the second date of culture (4463 kg.ha-1) compared the first date of culture (3212 kg.ha-1) at two irrigation methods. Generally, using porous clay capsules technique, rice culture could be provided without yield loss at arid and semiarid reigons.

The inputs of water and fertilizer are important in agricultural production, with a shortage of each one reducing the yield of the product. The role and importance of each of the factors of water and fertilizer separately can be effective in increasing yield. The purpose of this study was to evaluate the effect of irrigation and nitrogen fertilizer on production function and water productivity in peanut plant in Guil cultivar. The experiment was conducted as a split plot based on randomized complete block design with 3 replications, in 2009 in Astaneh Ashrafiyeh. The main treatments included: without irrigation (control) and irrigation with intervals of 6, 12, and 18 days, while the sub treatments were nitrogen fertilizer rates of 0, 30, 60, and 90 kg ha-1. A quadratic equation was used to estimate the water-fertilizer production function. The results of production function estimation indicated that seed yield increased with nitrogen fertilizer up to 60 kg ha-1. But, with a gradual increase in nitrogen fertilizer, yield was reduced. Increasing nitrogen fertilizer from 60 kg ha-1 in different amounts of water consumed had no effect on yield increase. Water productivity and the water utilization rate in the irrigation interval of 6 days, with consumption of 328 mm, was the highest. In the irrigation interval of 6 days and consumption of 60 kg N-fertilizer ha-1, the maximum amount of water productivity was 0.96 kg m-3.

With the increase of population, the optimal use of water resources is necessary. This study was carried out to evaluate the impact of different levels of irrigation on the yield, yield components and water productivity of corn using single and double row drip irrigation systems (Tubes type). . The experiment was conducted in a split plot design based on the randomized complete block design (RCBD) with three replications in 2012 in Hajiabad, Hormozgan Province. The treatments were comprised of three levels of irrigation as the main plot (100, 80 and 60% water requirement) and two patterns of irrigating water pipe installation (normal and every other row) as a sub-plot of the design. The results showed that irrigating with the 80 percent water requirement, in comparison with full irrigation, increased the total yield by 1.4%, the seed weight by 1.8%, the number of seeds per row by 8.7%, and the number of seed row per maize by 13%. In spite of yield superiority in the pattern of normally irrigating water pipe installation (10055.56 kg ha-1), against every other row installation (9366.67 kg ha-1), water productivity was more in every other row installation (1.089 kg m-3). Therefore, partial root-zone drying was recommended by the irrigation of the 80% plant water requirement for the maize in the region.

Drought and its stress are the most important factors for crop production. This research was carried out for determination of crop water production function and investigation different levels of irrigation water on yield component total dry matter, grain and harvest index in different irrigation levels for corn in Khoozestan in a research farm in Islamic Azad University, Dezfool branch in 1014-2015. It was conducted in randomized complete block design with four treatments including 60%, 80%, 100% and 120% of full irrigation (W60, W80, W100 and W120, respectively) and four replications. According to the total dry matter, grain and shot, the best crop water production function was obtained as linear function with R2 equal 0.897, 0.682 and 0.927, respectively which was significant in level of 1%. In comparison to W60 treatment, full irrigation treatment (W100) increased total dry matter yield (70%) but in comparison to W100, W80 treatment decreased total dry matter yield (5%). On the basis of total dry matter yield and grain (4.8 and 2.06 kg/ m3), maximum harvest index (0.43) and maximum water use efficiency were obtained for W80 treatment. The results show that the best grain yield and water use efficiency were related to W80.

In order to study the effects of deficit irrigation on yield of tomato, an experiment was conducted in Jiroft. The experiment treatments were arranged as randomized complete block design with three replications. The irrigation regimes consisted of full irrigation, regulated deficit and partial root zone drying irrigation (RDI75, RDI55). The results showed that deficit irrigation resulted in water saving at the rates of 16-34 percent. The highest yield (202.65 ton/ha) was produced by full irrigation. There was no significant difference between yield and fruit weight of full irrigation treatment and 75 percent water replacement in partial root zone drying. The highest water use efficiency was 45.6 kg/m3 was obtained in 75 percent water replacement in partial root zone drying. Also, despite the same water consumption of 75 percent water replacement in partial root zone drying and regulated deficit, yield was decrease 16.1 percent. Therefore, it can be concluded that 75 percent water replacement in partial root zone drying, which resulted in a non-significant decrease of yield and while resulting in a 25 percent decrease in water use and increased 14 percent of water use efficiency, would be a promising water-saving method as in Jiroft.

One of the main reasons of crop yield reduction in Iran is salt stress and providing proper strategies is necessary for mitigating the effect of this stress. So, a factorial experiment was conducted to improve the salt stress damages on two canola varieties in a randomized complete block design with three replications at the Research Greenhouse of Agricultural Faculty of Tarbiat Modares University. Treatments included 3 levels of control, moderate, and severe salt stress (0.4, 5 and 10 dS m-1), calcium silicate at two rates (0 and 8 kg ha-1), two levels of zeolite (control and 8 ton ha-1) and two varieties, namely, Zarfam and Sarigol. Results showed that application of zeolite increased Zarfam yield in soil with a light texture and had no significant effect on Sarigol. Under moderate salinity, zeolite, and calcium silicate treatment, Zarfam produced higher oil percentage (more than 57%) compared to Sarigol at severe stress and without application of zeolite and calcium silicate. Also, Sarigol in the treatment with no salinity stress and zeolite and only application of calcium silicate had the highest oil yield while the lowest oil yield (60 percent lower) was obtained at severe stress, application of zeolite and without application of calcium silicate . In the treatment with moderate salinity and non-application of zeolite and calcium silicate, Zarfam had the highest SPAD, while Sarigol, under moderate stress, application of calcium silicate and without application of zeolite, had the lowest SPAD (more than 32% difference). Generally, salt stress reduced yield and yield components of both varieties and application of zeolite and calcium silicate decreased the damages of salt stress in some traits. Besides, Zarfam showed better response to the calcium silicate and this treatment was more effective in comparison with zeolite in both canola varieties.

In order to evaluate the effect of Azotobacter chroococcum different strains on morphophysiologic characteristics, seed yield and yield components of fall rapeseed (Brassica napus L.), an experiment was conducted in Rasht. The experimental design was completely randomized block, with three replication. Investigated treatments were including seed inoculation with Azotobacter different strains (6, 9, 11, 12, 13, 14, 15, 16, 19, 21, 23, 25, 28, 35 and 38) and chemical fertilizer application (full Urea fertilizer application) and without seed inoculation conditions (control). Results showed that Azotobacter strains significantly affected on all traits except plant height, weight of 1000 seeds, stem diameter and number of secondary branches. The most distance of the first secondary branch until ground obtained by A. chroococcum strain 35, as A. chroococcum strain 14 caused the highest of silique length, dry weight, seed yield and number of seeds per silique. The most leaf erea, dry weight, seed yield and yield components caused by A. chroococcum strain 12. Generally, A. chroococcum strain 12, A. chroococcum strain 14 and A. chroococcum strain 9 had the more positive effect on traits compared with other strains. Results of this experiment showed the use of A. chroococcum increase quantitative and qualitative characteristics of canola in relation to full Urea fertilizer application and the savings in fertilizer consumption and reduce environmental degradation, therefore can be used as supplementary of chemical fertilizer.

This experiment was carried out at the Agricultural Research Station of Bu-Ali Sina University to study the effect of different tillage methods on bulk density, yield, and yield components of barley (Hordeum vulgare) cultivars under rainfed conditions. Three levels of tillage (CT: conventional tillage, MT: minimum tillage and NT: no tillage) and five barely cultivars (V1: Local V2: AbidarV3: Valfagr V4: Bahman and V5: Makouei) were evaluated in a factorial arrangement in a completely randomized block design with three replications in the growing season of 2010-11. Traits of bulk density plant height, grain yield, yield components, biological yield, and harvest index (HI) were evaluated. The results showed that maximum value of bulk density (1.09, 1.26 and 1.29 g cm-3 for 0-10, 10-20 and 20-30 cm of sampling depth, respectively) was observed at MT treatment. But, there was no significant difference between MT and NT treatments for this trait. In comparison of cultivars, maximum bulk density was achieved with Valfagr cultivar. Using chisel plow (MT treatment) produced maximum plant height (70 cm) and yield components (513 numbers of spike m-2 and 19.2 grain spik-1). Also, among cultivars maximum plant height (72.7 cm) and grain number spike-1 (23.2 grain spike-1) belonged to Valfagr cultivar. Also, results showed that V3×MT treatment had the highest grain yield (3100 kg ha-1). Therefore, the findings of the study recommend using chisel plow (MT treatment) and Valfagr cultivar.

Soil moisture measurement and its control essential elements to employ optimal management methods for reducing water consumption and product quality improvement. In order to investigate the effect of soil matric potential and tube layout on yield and water use efficiency of greenhouse cucumber، a field experiment was carried out during 2010 and 2012 growing seasons at an experimental farm in Jiroft territory. The treatments were laid out in strip split plot a Randomized Complete Block Design with three replications. The treatments were comprised of fore soil potential including 45، 55، 65 and 75 c-bar tension in main plot and sub plot consisted of two irrigation systems (surface drip irrigation system (S1)، subsurface drip irrigation system (S2)) and two tape position patterns (conventional (L1) and alternative (L2)). The results showed that in comparison to 45 and 55 c-bar tension، parsimony of water usage equal 700 m3 ha-1 achieved. Moreover yield، LAI، height of plants، length and diameter of fruit decreased 1. 2، 1. 9، 0. 35، 0. 73 and 1. 2 percent respectively but water use efficiency increased 10. 5 percent. On the other hand yield and water use efficiency in subsurface irrigation increased about 6 and 6. 13 percent respectively compared with surface irrigation. Also in conventional pattern yield and water use efficiency increased about 7. 5 and 7. 7 percent respectively compared with alternative pattern. Therefore، the potential point of 55 c-bar tension considered as the optimal starting point for irrigation.

Water stress is one of the inhibitors in crops and drug crops seed germination and seedling growth. There are different ways to minimize the harmful effects of water stress tensions. Seed priming is one of the popular and efficient techniques for increasing germination efficiency. The most important kind of priming is osmo priming (imbibing seeds in osmotic solutions with different osmotic pressure or potential); and hormo priming (to effect hormone compounds on seeds). This research was conducted to investigate the effects of salicylic acid (Aspirin), K CL, and Na Cl on some morphological aspects, yield, and yield components of fennel (Foenicilum vulgar Mill) in water stress condition in laboratory and on research farm, College of Agriculture, University of Shahid Bahonar, Kerman, Iran in 1390 crop year. In lab; an experiment, as randomized complete block (Factorial design) with 3 replications was conducted. Fennel seeds treated with salicylic acid in 4 levels (0, O.1, 0.5, 1 m. molar concentration); K CL in 4 levels (0,-1, -1.5, -2 M pascal osmotic potential); Na CL in 4 levels (0, -1, -1.5, -2 M Pascal osmotic potential) For 24 hours in 20◦C temperature. In salicylic acid treatments, the third level (0/5 m molar) had highest mean germination speed and seedling shoots and root length. In K CL treatments the second level (-1 Mp) had highest germination speed and seedling shoot and root length. In Na CL treatment -1.5 Mp treatment showed highest seedling shoot and root growth. In the farm experiment; the best priming treatments that were obtained in lab; were used and a randomized complete block in split plot design with 4 replications was conducted. Irrigation in 2 levels (no water stress, water stress) was as main plots; and different priming treatments in 4 levels (distilled water as control, Na CL with- 1Mp osmotic potential, K CL with -1.5 Mp osmotic potential, salicylic acid in 0.5 m. molar concentration) were used as subplots. The results showed that water stress and priming treatments, had significant effects on seed yield, biological yield, umbels number/pl, and umbellates number/ umbel in fennel; But plant height and harvest index were not significant. 1000 seed weight was affected by interaction effect of water stress × priming. Water stress increased water extract percent, but decreased total yield water extract.

As increasing of disaster such as drought and pest invasion in recent decades, it is essential to find out practical approaches in optimizing water use and water management for reduce the adverse effects of this disaster in agriculture. In order to study the effects of water stress and pest stress on corn yield, an experiment was conducted in the research farm of Isfahan University of Technology. In sprayed and non sprayed of the field, a factorial design, based on the completely randomized block, was carried out with three treatments of irrigation regimes including intensive stress (50% water requirement), moderate stress (75% water requirement) and no water stress in four stages of corn growth from seed germination until tasseling, from tasseling until milky, from milky until harvest and the whole period of corn growth, in four replications for one year (2005). The results showed that applying water stress on corn reduced seed yield between 6-62% and also decreased other agronomic characters except protein percentage. Water stress in non sprayed condition, reduced significantly more physiological characteristics of corn compared to the sprayed condition. Intensive water stress and pests stresses increasd 3 and 13% of percentage protein, respectively. In sprayed condition applying moderate stress in first stages of corn until the first of third stage is suggested in drought condition.

Biofertilizers can be used as complementary in sustainable agriculture. The main target of this study was effects of nitrogen and phosphorus fertilizers and chemical fertilizers on wheat yield and yield components in two soil types. Experimental design as the factorial formed completely randomized design with three replications was executed. Experiment Factors included two soil types (sandy loam and clay loam) and 9 fertilizer treatments. For the experiment implementation used 100 gram per hectare of Nitrokara (Azorhizobium caulinodans) and Barvar 3 phosphorus (Pseudomonas putida، Strain P13، Pantoea agglomerans، Strain P5 and Pseudomonas putida، Strain MC1) biofertilizers in single and combined forms by method of seed inoculation. The results showed positive effects of clay loam type and inoculation of two biofertilizer types especially in the presence of 50% of chemical fertilizers on shoot dry weight، root dry weight، number of grains per spike، 1000 grain weight and wheat grain yield. The results showed 100% chemical fertilizer and phosphorus biofertilizer in combination with 50 % of chemical fertilizer treatments showed the highest effect in most characteristics and control treatment showed the lowest effect in this characteristics. Nitrokara biofertilizer in combination with 50% of chemical fertilizer had the maximum 1000 grain weight. Phosphorus biofertilizer in combination with 50% of chemical fertilizer on wheat yield and yield components showed a better effect than Nitrokara biofertilizer. The results of this research showed by combining biological and chemical fertilizers can reduce consumption of chemical fertilizers.