The Compressing of soil due to traffic of agricultural machines and tillage tools which affect on the soil physical features and performance of agriculture production is going to become worst by mechanization of agriculture and vast application of tools. In this research, as a split plot experiment based on a completely randomized blok desing has been used and the effect of three types of tillage (moldboard plow-without moldboard plow and chisel plow) on two levels with and without subsoiling on selected plant and soil parameters was studied. Soil parameters under study included:1-moisture content 2-Bulk density of soil ,before and two months after planting in two depth of (0-10cm) and (10-20cm)and plant parameters included:1-The percentage of germination 2-plant dry matter. analysis of variance and Duncans multiple range test for comparision of means has been used. It was determined that in plots with subsoiler, the treatment of bz (subsoiler+moldboard plow)had a significant difference with az(subsoiler+chisel) and cz (subsoiler+without moldboard).On the other hand in plots without subsoiler a chisel showed a siginificant difference with b (moldboard plow) and c(without moldboard plow).

In order to understand the response mechanism of corn (Zea maize 704 Single cross) seed germination and seedling growth to acid rain stress, this study in a randomized complete design with six treatments were performed and then examined by nineteen adjective related to seed germination and seedling growth. Simulated acid rain at pH2, 3, 4, 5, 6 and control (distilled water-pH7) and then examined by nineteen adjective related to seed germination and seedling growth. The results indicated water absorption in all treatments was lower than control except pH4. the germination percentage (GP), germination energy (GE) and seedling vigour index (SI) was not changed by acid rain higher at pH2. However, was stopped all germination characteristics in pH2 (PIncreased acidity with a decline in pH2 reached zeroSeedling growth was affected by acid rain so that the control showed better results than other treatments. According to the results, water reduction acidity and toxicity of acid rain can inhibit seed germination, development and establishment of the corn.

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

In order to determine the effects of planting dates and density on the yield of the Single cross 704 in Haji-Abad region, an experiment was carried out for two years (1999-2000) in split plot design with three replications in Haji-Abad Agricultural Research Station. The main plots included four planting dates (6thJuly, 16 July, 27 July and 6thAugust) and subplots included two row space (60 and 75 centimeters) and sub subplots included three distance shrubs on row (15, 18 and 21 centimeters). The collected data were analyzed statistically based on variance analysis on yield for each year and combined variance analysis for two years. Effect of year was significant at 1% level. Effect of planting date was significant at 1% level and highest yield was obtained in the third planting date (21 July). Effect of row spaces was significant at 1% level and average yield in 60 cm row space was more than of 75 cm. Effect of shrub distance on row also was significant at 1% level and the highest grain yield (11.182 T ha-1) was obtained from shrub distance 18 centimeters.  

Today, efficient management and optimal use of wastewater resources in agriculture play an important role in reducing environmental hazards and surface water resources. In this study, in order to Evaluation of Treated Wastewater Irrigation Effect on yield components and yield of maize (Single cross 704), an experiment carry out in factorial experiment based on a completely randomized design with treatments included,Water source factor Wastewater, Well water, Irrigation subsurface method and drip method with three replication in 2018-2019 under lycimetric conditions, at the Sari Agriculture and Natural Resources University (SANRU). Based on the results, the effect of irrigation water source on grain yield, biological yield, biomass yield, 1000-seed weight, number of seeds per row and harvest index was very significant (P≤,0. 01). So that the average of the mentioned traits in irrigation with treated wastewater was higher than well water with the values of 918. 66 kg/ha, 1319. 55 kg/ha, 4421. 02 kg/ ha, 302. 13 g, 13. 66 and 81, respectively. Also, the effect of irrigation method on grain yield, biological yield, biomass yield and number of grains per row of corn was very significant (P≤,0. 01). Based on the results, the subsurface irrigation method showed Superior results than the drip irrigation method. Irrigation with wastewater provides more nutrients especially nitrogen to the plant, compared to well water, which will increase the growth of plant organs. Therefore, plant yield increases with increasing the efficiency of the plant photosynthetic system. Finally, according to the findings, the increase in yield and yield components can be attributed to the superiority of using the wastewater source in the subsurface method compared to the well water source in both irrigation methods (subsurface and drop bar tape), and recommended it as a suitable alternative in irrigation of crops, especially corn.

Lack of water resources, especially in the agricultural sector, is one of the common problems in sustainable development. For this purpose, the present study was conducted to investigate the effect of deficit drip irrigation method on yield, yield components, and water use efficiency of corn (Single cross 704), in the crop year 2017-2018 in the research farm of College of Aburaihan, University of Tehran, in Pakdasht City. The experiment was performed as a randomized complete block with three levels of 100% (D1), 75% (D2) and 55% (D3) water requirement of corn in three replications. The highest biomass yield was observed at the level of 100%, and with the application of 75% and 55% deficit irrigation, crop yield decreased by 25% and 50%, respectively. Also, the highest grain yield was 14805 kg/ha in 100% treatment and the lowest was 10227 kg/ha in 55% level. The highest biomass water use efficiency was obtained for the treatment of 75% drip irrigation and was equal to 3. 55 kg/m3 of water consumption. Therefore, it can be said that a drip irrigation system with 75% water requirement is the optimal system and its use is recommended.

In order to evaluation of N-Fertilizer sources and amounts effect on yield and its components in Single cross 704 corn, an experiment was conducted in research field of Islamic Azad University-Miyaneh branch. In this study, two levels of  N-Fertilizer including Amonium Nitrate and Urea with amounts including 100, 160 and 220 Kg of pure Nitrogen per hactar as a factorial design in compeletly randomized blockes with four replications was run. One of plots in each treatment was considered as control without N-Fertilizer receiving. Plants was planted as farrow system on the rows with 75 cm intervals and 67.000 plants/ha density in 23th of Ordibehesht. N-Fertilizers were applied in three times including simultaneously with planting, four and eight leave stages as top dressing. The plants were selected from 5 m2 of three middle rows for determining of seed yield and biological yield in physiological ripping stage and 15 plants randomizly were selected from each plots for yield component and head numbers in a plant in row and seed number in row were counted and 1000 seeds weight was evaluated. It is revealed that Amonium Nitrate application has higher yield than Urea application and 160 and 220 Kg/ha of pure Nitrogen has the same or more then yield of control and 100 Kg/ha treatment. The reason of high yield in Amonium Nitrate treatment has contributed with corn efficiency in Nitrogen Uptake. Low yield in Urea treatment is related to Nitrogen wasting by sublimitation and washing.

In order to investigate the effect of nitrogen and micronutrient amounts and fertilizing methods on corn (S.C. 704) quantity, an experiment was carried out at research station of Islamic Azad University, Kerman branch in 2005. The experimental design was the split split plot based on completely randomized block design (BCRD) with 3 replications. Source of nitrogen fertilizer, Urea, were considered in three levels (300, 450 and 600 Kg/ha) as the major plots with (1/2 and 1/3) fertilizer divide methods of each as the subplots. The micronutrient factor was also considered in two levels (0 and 3 ppm) as sub-subplots. Cultivation was performed as furrow system with 75cm between rows and 15cm between plants on the rows in 30th April. Nitrogen fertilizer was sprinkled in three time stages: synchronous with cultivation and 4 and 8 leave stages through fertilizing methods. The micronutrients were also sprinkled in 4 leave stage in two consecutive weeks. Plants were selected from 5m2 of three middle rows for determination of grain and biological performance at physiological ripening time. 15 plants were also selected randomly for measuring yield components. The quantity characteristics of corn, number of row in each corn, number of seed in each row, total weight of plant and weight of 1000 seeds were determined. According to the results, using 600 Kg/ha of Urea with 1/2 fertilizer dividing method resulted in higher yield than other treatments. Also, micronutrient application at 3ppm level only significantly improved total weight of plants and weight of 1000 seeds.

One of the problems associated with the production of granular microbial fertilizer is the elimination of bacteria in the drying process of fertilizer. One solution for this problem is using thermal resistant phosphate solubilizing bacteria (PSB). In this study, the efficiency and effectiveness of some PMFs prepared by using two thermal resistant PSB (isolates RPS9 and RPS7) and one thermal sensitive PSB (isolate RPS4) in the basal formulation of rock phosphate (45 g), bagasse (30 g) and sulfur (15 g) were evaluated on the maize growth. The experimental design was CRD with 7 treatments including control treatment (without chemical and microbe fertilizer), triple super phosphate fertilizer treatments at the rates of 100% and 50% of the fertilizer recommendation (equivalent to 300 and 150 mg/kg soil, respectively), with bacterial treatments (RPS4, RPS7, and RPS9), in three replications. The results obtained from the greenhouse experiments showed that total wet and dry weight of the plants and uptake of phosphor in the root and shoot of corn S. C. 704 were significantly influenced by the PMFs. RPS4 bacteria treatments had similar performance to triple super phosphate 100% and RPS9 had similar performance to 50% triple super phosphate. RPS7 had lower performance than the other two bacteria. From the two heat resistant isolates that were recently isolated and both belonged to the species Pantoea agglomerans, RPS9 seemed more promising for this purpose.

The CSM-CERES-Maize model was calibrated and evaluated by using the field and weather data set of a two-year field experiment previously carried out on silage corn at the Agricultural Research Center in Varamin. The data set included soil, crop, and weather data of a two-year corn experiment with four irrigation levels and three N fertilization levels. Twelve treatments were arranged in a strip-plot design in a randomized complete block with three replications during the 2003 and 2004 growing season. Data collected in the field included weight of biomass, leaf area index, and important physiological dates such as silking, anthesis, grain filling, and harvest maturity during the growing period. The maximum leaf area index and weight of biomass at physiological harvest, along with anthesis and maturity dates were used in the calibration process. The biomass weight during the growing season was used for the model evaluation. The results indicated that GENCALC tool is capable enough to be applied for determining genetic coefficients of maize with acceptable accuracy. The result of calibration of the model produced the following statistics, root mean square errors (RMSE) for anthesis and maturity dates were 1 and 2 days, 980 and 1313 kg ha-1 for weight of biomass and 0.75 and 0.44 for maximum LAI in the years of 2003 and 2004, respectively. Genetic coefficient required by the CSM-CERES Maize model including P1, P2, P5, G2, G3, and PHINT were found to be 236 (oC), 0.4 (days/hr), 790 (oC), 833, 8.5 (mg/day), and 55 (oC), respectively. The evaluation of the CSM-CERES-Maize showed that the model was able to simulate weight of biomass for the silage maize accurately with root mean square errors (RMSE) ranging from 9 to 1483 kg ha-1 and coefficient of determinations (r2) ranging from 0.86 to 0.99 for all of the 12 treatments for two years. It is concluded that the GENCALC tool was capable of successfully determining the cultivar parameters required by the CSM-CERES-Maize model and that the model itself was well calibrated for the data set used in this study.