جستجوی مقالات مرتبط با کلیدواژه « sweet corn » در نشریات گروه « آب و خاک »

Planning for the best use of water resources in agriculture is inevitable. In this regard, the method of subsurface drip irrigation can, in addition to reducing the amount of irrigation water, increase crop yield. This study was conducted to investigate the different levels of under-irrigation and over-irrigation on yield indices and plant traits of sweet corn cultivar CHASE, under subsurface drip irrigation system in a randomized complete block design with four treatments of 20 Percent over-irrigation, equal to water requirement, 20 and 40 Percent under-irrigation in four Repeated. The results showed that in general, the effects of under-irrigation and over-irrigation on cob yield, 1000-seed weight, uncovered cob diameter, pod-free cob length, number of cob rows and number of seeds were significant. Also, based on the results, it can be stated that by reducing the amount of water consumption, the yield of the product decreases linearly. The highest and lowest cob yields were obtained in over-irrigation treatments and 60 Percent of water requirement with an average of 30.4 and 19.9 tons per hectare, respectively. Accordingly, with a 20 Percent reduction in water consumption compared to full irrigation, only 4.72 Percent of the crop is significantly reduced. This is while with a 20 Percent increase in irrigation water, the yield of cob increases by 10.54 Percent. 1000-seed weight in full irrigation and 20 Percent low irrigation treatments was 375.7 and 372.6 g, respectively. There was no significant difference between over-irrigation and 20 Percent under-irrigation treatment. There was a significant difference between the means of ear yield indices, length and number of seeds per ear row in all irrigation treatments.

In the water scarcity condition، using deficit irrigation and appropriate sowing patterns are the most strategies to improve water productivity. An experiment was conducted to investigate the effect of different sowing patterns (SP) and some deficit irrigation methods on yield، water use efficiency (WUE) and yield response factor (Ky) of sweet corn. The experimental design was a split plot in a randomized complete block design with three replications. Treatments were including two irrigation intervals (6-day S1، and 10-day S2،) as main plots، single-row SP (every furrow irrigation (EFI) I1، variable alternate furrow irrigation (VAFI) I2، and fixed alternate furrow irrigation (FAFI) I5) and double-row SP (EFI، I3، VAFI، I4 and FAFI، I6) as sub plots. Results have shown that the difference in grain yield between treatments was significant، but non-significantly between deficit irrigation treatments. Runoff in I1 and I3 treatments were higher than other treatments، and also FFI treatments were also more VAFI treatments، and therefore، the amount of absorbed water in VAFI was more than FAFI treatment. Runoff was reduced by 24% when the irrigation interval was increased from 6 to 10 days. Runoff in the double-row treatments was reduced and thus more water absorbed when they are compared to the single-row treatments. Relationship between crop evapotranspiration (ETc) and yield was obtained a relatively strong linear relationship (R2 = 0. 80) and Ky was estimated 1. 14. The WUE comparison of maize in different treatments have shown that alternate furrow irrigation with 50% saving of water is higher beneficial than EFI.

In the present study, field experiments were carried out at the research fields of the Agricultural Faculty of the University of Tabriz in a sandy-loam soil in order to determine the wetting pattern dimensions and soil moisture distributions in the vicinity of an emitter and also in a domain between the two adjacent emitters in a subsurface drip irrigation system. The obtained data from experiments were compared to the results from HYDRUS two-dimensional and three-dimensional simulations. Results showed that HYDRUS-3D was more efficient than HYDRUS-2D in simulating wetting pattern dimensions on the constructed soil profiles one just at the emitter location and the other between the two adjacent emitters with RMSE values of 2.54 and 3.96, respectively. Comparison of the obtained values from the two and three dimensional simulations showed that the two models had acceptable accuracy in simulating the soil water distributions on the profile at the emitter location. Also, by increasing the irrigation duration from 1 hour to 4 hours, the value of RMSE between soil moisture values obtained from the two and three dimensional models decreased from 0.068 to 0.025. Considering the good accuracy of the three dimensional model, the calibrated model was run for three different emitter installation depths and the suitable emitter installation depth for sweet corn production in the studied soil was recommended to be 30 cm based on the plant maximum water need, minimum deep percolation and evaporation losses and the plant rooting system.

Effect of urban sewage and nitrogen on soil chemical characteristics in sweet corn was evaluated in Yasouj region at 2009. Five irrigation treatments were managed; common water during entire period of growing season as control (I1); urban sewage during the first half of growing season (I2); urban sewage during the second half of growing season (I3); alternate urban sewage and common water (I4) and urban sewage during entire period of growing season (I5) and three nitrogen rates (N0=0، N80= 80 and N160=160 kg N ha-1) in a completely randomized design with three replications. Results indicated that the soil N، P and K concentrations in treatment I5 had a significant difference compared to the other irrigation treatments. Irrigation levels were also exhibited a significant difference in soil organic matter and EC. Maximum and minimum of soil organic matter were observed in I5 (%0. 45) and in I1 (%0. 33)، respectively. Maximum and minimum of soil EC were found in I5 (2. 0 dsm-1) and in I1 (1. 4 dsm-1)، respectively. Irrigation treatments did not show a significant change in soil pH. The effect of irrigation and interaction between irrigation treatments and nitrogen rates were not significant on available forms of Fe، Zn، Cu and Mn in soil. The effect of nitrogen fertilizer was significant on soil N content. Maximum (%0. 034) and minimum (%0. 030) of soil nitrogen were noticed in N160 and N0، respectively.

Iron deficiency is a worldwide nutritional constraint in agricultural lands especially in calcareous soils. Cultivation of crops tolerant to Fe-deficiency is an approach to combat Fe deficiency. The aim of this investigation was to evaluate Fe-efficiency of selected important crops in Iran. A completely randomized block design in triplicates was conducted at IUT research greenhouse in fall 2006. Sweet corn (Hybrid K.S.C. 404), grain corn (Hybrid S.C. 500), safflower (cvs. S3110, S-411), sunflower (Hybrid Hyson) and durum wheat (cv. Shuga) were grown in a nutrient solution at two Fe levels (1 and 10 µM Fe-EDTA). The results showed significant (P < 0.01) variation among the studied crops in Fe-efficiency. Corn hybrids were more sensitive to Fe deficiency (FeE = 26%) as compared to other studied crops, and the greatest reduction was observed in their shoot dry matter at 0.1 mM Fe- EDTA treatment. In contrast, the lowest decrease in root and shoot dry matter weight under Fe-deficient condition was found for durum wheat (FeE=94%). Comparing the calculated Fe-efficiency using different indices showed that Fe concentration and content in the whole plant, shoot and root had no relationship with crop tolerance to Fe deficiency.