h.r. eshghizadeh

The experiment was completed to evaluate the responses of forage yield and silage quality of dual-purpose corn hybrids to urea fertigation. For this purpose, two studies were conducted each as a split plot experiment based on a randomized complete block design with three replications at two locations in research farms of College of Agriculture, Isfahan University of Technology, Isfahan, Iran, in 2016.  Two levels of nitrogen fertigation including 150 and 200 kg ha-1 in Lavark Research Field -Najafabad city; 200 and 250 kg ha-1 in Shervedan Research Field- Flavarjan city with urea fertilizer, N= 45%, and 20 forage-grain corn hybrids were designed as main and sub plots, respectively. The results showed that the increased application of nitrogen fertilizer improved biological yield in Shervedan field and dry matter percentage and silage yield in both locations, but had no effect on the ratio of forage components including leaves, stems and ears to total forage weight. The protein concentrations of silage hybrids increased significantly as a result of increasing nitrogen application in Shervedan. Also, with increasing nitrogen fertilizer, the amount of ash in both locations increased, but insoluble fibers in neutral detergent and insoluble fibers in acidic detergent decreased. The interaction effects of nitrogen × hybrid on silage acidity was significant in Shervedan. At Shervedan field, the highest biological yield (298,000 kg/ha) and silage dry matter percentage (29.8%) were observed in AGN591 and Whichita with application of 250 kg/ha N-fertilizer. AGN756 had the highest biological yield (27,200 kg/ha) and silage dry matter percentage (28.6%) upon application of 200 kg/ha N-fertilizer in Lavark field station. It seems that in each region, by using the appropriate amount of nitrogen fertilizer and selecting high-potential yield hybrids, both acceptable quantitative and qualitative yields of corn silage can be achieved.

To study the response of corn hybrids to nitrogen under different conditions two field experiments were conducted in a split plot based on a randomized complete block design with three replications in Lavark and Shervedan Research Farms of College of Agriculture, Isfahan University of Technology, Isfahan, Iran, in 2016. The nitrogen fertilizer management (including 150 and 200 kg ha-1 in Lavark; and 200 and 250 kg ha-1 in Shervedan) regions was assigned to main plots and 20 grain–silage corn hybrids were assigned to subplots. The results showed that increased nitrogen fertilizer improve the LAI and CGR in corn hybrids. At Shervedan region, plant height in Maxima corn hybrid significantly increased by increasing of nitrogen. Increased nitogen fertilizer, also increased the amount of photosynthetic pigments in Shervedan and chlorophyll a content in Lavark region. The highest biological and grain yield were, respectively, obtained in AGN591 (29800 kg ha-1) and Maxima (13150 kg ha-1) hybrids in Shervedan region and in AGN756 (27200 kg ha-1) and AGN735 (11692 kg ha-1)in Lavark region with increased application of nitrogen. Therefore, depending on the purpose of the production system (e.g. grain or silage) the results of this research can be used to select corn hybrid and proper amount of nitrogen fertilizer to obtain acceptable yields and also reduce the adverse environmental effects of improper application of nitrogen fertilizers.

World climate change is an accepted important subject but its negative effects are severe in arid and semi-arid areas of Iran. So, in the present study, two climate scenarios including RCP 8.5 (critical scenario) and RCP 4.5 (moderate scenario) during 2020, 2030, and 2040 decades and their effects on temperature changes in the wheat growth period in five cities of Isfahan province including Isfahan, Najaf Abad, Chadegan, Burkhar, and Meimeh have been investigated. The survey of temperature changes during wheat growth in the next decades showed that Burkhar, Isfahan, Najaf Abad, Chadegan, and Meimeh, respectively will experience more days with a temperature higher than 30°C in 2020, 2030, and 2040 decades than the mean of two recent years (2017-2018). Furthermore, in comparison with present conditions, the most changes in the number of days with a temperature higher than 30°C in next decades climates (2020, 2030, and 2040 decades) will be in Burkhar, Meimeh, Chadegan, Najaf Abad, and Isfahan, respectively. The range of changes percent in the number of days higher than 30°C in next climate conditions rather than present condition will be varied between 5 percent (Isfahan) till 97 percent (Burkhar). The changes percent in all studied cities were more in RCP 8.5 than RCP 4.5. During wheat growth, the number of days less than zero°C will be less in Isfahan, Burkhar, and Meimeh while will be more in Najaf Abad and Chadegan. The evaporation- transpiration will be increased in the next decades during wheat growth. As a result, planning and using compatibility strategies for each city is important to guarantee wheat production.

The present study aimed to evaluate the growth and water use efficiencies of eight late-maturing corn hybrids in comparison to the common use of KSC704 and Maxima-FAO530 under different water-nitrogen management systems. Two irrigation regimes (based on 50% soil-water depletion as the normal irrigation and, on average. 16% less than normal as the deficit irrigation) and two nitrogen (N) application managements (3 and 16 split-application of 150 kg N from Urea, 45% N) were induced using the split-split plot experiment based on a completely randomized block design with four replications at Research Field of Isfahan University of Technology on 2017. The results showed that yield, forage and leaf area index were significantly (P<0.01) affected by the interaction of three studied factors (Irrigation × Nitrogen × Corn hybrid). For different corn hybrids, more water use efficiencies were achieved by deficit-irrigation regime and 16- split-applyication of N; in this regard, the SC719 hybrid had the highest value of 3.45 kg m-3. Generally, the performances of the studied late maturing corn hybrids were higher than those of the control hybrids of SC704 and SC530 at this planting date, which could be improved by using the deficit-irrigation regime and more split-application of the N fertilizer.

Root depth and distribution have an important role in drought resistance and optimization of moisture content of soil. This research was carried out in order to consider of root response of triticale genotypes to water stress and recognition of root trait that can effective in resistance of water stress. This experiment was in a factorial experiment based on completely random design on the year 2009. The genotypes of triticale was included (i) ET-82-15 (ii) ET-82-8 (iii) ET-82-17 and commercial triticale genotype Juanillo-92. Two irrigation regimes included 100 and 50 % of field capacity، respectively. The result showed that water stress result in increased 9% of root depth in each plant. Differences between minimum root depth was observed in ET-82-15 rather than maximum root depth in Juanillo-92 was approximately 8. 2 centimeters. Late irrigation caused to diminish 25% of root length. Differences between maximum root length in ET-82-15 and minimum root length in ET-82-17 was not significant (p)

The management and application of organic wastes in agricultural lands decreases environmental risks and increases utilization of these matters. The objective of this research was to investigate and compare the effect of polyacryl factory sewage sludge (PSS), municipal compost (MC) and cow manure (CM) on soil properties and on yield and growth of maize (single cross 704, Zea mays L.). The treatments were control (without any organic waste) and application of PSS, MC, and CM at two rates (15 and 45 t ha-1). This research was done in the research farm of Isfahan University of Technology (Lavark-Najafabad). The experimental design was a randomized, complete block with three replications. Treatments were incorporated into the soil before the maize planting (on 23 June 2008) and soil sampling was performed after 132 days (Simultaneously with maize harvesting). Application of the organic wastes resulted in significant increase soil organic matter (SOM), total nitrogen (TN) and saturated hydraulic conductivity (Ks) and significantly decreased bulk density. However, saturated hydraulic conductivity was decreased by application of PSS. Application of 15 and 45 t ha-1 of PSS reduced Ks more than 14% and 42%, respectively, compared with control; however, the reduction was significant only in the plots which received 45 t ha-1 of PSS compared with control. The results of plant yield and growth showed that leaf area index (LAI), plant length, biological yield, 1000 seed weight and seed yield increase due to the application of organic wastes.