Showing 171 results for Yield
R Amiri Chaijan, M Khosh Taghaza, Gh Montazer, S Minaee, M Alizadeh,
Volume 13, Issue 48 (7-2009)
Abstract
The objective of this research was to predict head rice yield (HRY) in fluidized bed dryer using artificial neural network approaches. Several parameters considered here as input variables for artificial neural network affect operation of fluidized bed dryers. These variables include: air relative humidity, air temperature, inlet air velocity, bed depth, initial moisture content, final moisture content and inlet air temperature. In aggregate, 274 drying experiments were conducted for creating training and testing patterns by a laboratory dryer. Samples were collected from dryer, and then dehulling and polishing operations were done using laboratory apparatus. HRY was measured at several different depths , average of which was considered as HRY for each experiment. Three networks and two training algorithms were used for training presented patterns. Results showed that the cascade forward back propagation algorithm with topology of 7- 13-7-1 and Levenberg-Marquardt training algorithm and activation function of Sigmoid Tangent predicted HRY with determination coefficient of 95.48% and mean absolute error 0.019 in different conditions of fluidized bed paddy drying method. Results showed that the input air temperature and final moisture content has the most significant effect on HRY.
S Safae Chaykar, H Samie Zade, M Esfahani, B Rabiei,
Volume 13, Issue 48 (7-2009)
Abstract
In order to study the correlation of agronomic, morphologic and physiologic traits and their effects on grain yield of rice genotypes in two environments (favorable irrigation and water stress), 49 genotypes were evaluated using a completely randomized block design with 3 replications in two experimental conditions. All practices and conditions were the same for the two experiments with the exception of irrigation, where under stress conditions no irrigation was applied at tillering stage. Comparison of means showed significant differences between genotypes in each environment. Also, differences between yield and yield components of each genotype under two conditions were significant. The results of phenotypic correlations showed that the highest positive and significant correlation with grain yield belonged to number of panicle per plant (0.95) in irrigation conditions and to number of filled grains per panicle (0.92) in water stress conditions. Stepwise regression analysis for grain yield introduced number of panicle per plant, relative water content (RWC), flag leaf length and number of spikelet per panicle, respectively, as effective traits in grain yield in irrigation conditions, however, in stress conditions, number of filled grain per panicle, number of panicle per plant and relative water content were effective traits in yield. The results of path analysis showed that the number of panicle per plant had the highest positive and direct effect on grain yield in the two environments. Factor analysis introduced four factors in the two conditions named yield and crop production, phenologic, harvest index and plant shape and appearance quality of grains factors. Therefore, to select high yield and drought tolerant genotypes, we need to consider number of filled grain per panicle, number of panicle per plant and relative water content. In addition, traits such as panicle length, number of spikelet per panicle, flag leaf length and width that showed significant correlations with grain yield in stress conditions should also be considered important and second to the above mentioned traits.
M Ahmadi, M Bahrani,
Volume 13, Issue 48 (7-2009)
Abstract
A study was conducted in 2007 to investigate the effect of nitrogen fertilizer rates (0, 30, 60 Kg ha-1) on some agronomic characteristics, seed yield and oil percentage in three Sesame(Sesamum indicum L.) cultivars (Dashtestan, Darab 14, and Zarghan) in Kaki region (Bushehr Province). The type of design was completely randomized block with factorial arrangement and three replications. Nitrogen(N) fertilizer had a very significant effect on agronomic characteristics, such as number of capsules in the main stem, number of capsules per plant, branches /plant, biological yield, seed yield ,and oil percentage, but had no effect on 1000 seed weight. There was no significant difference between the application of 30 and 60 Kg of N fertilizer ha-1 with respect to harvest index. Seed yield increased as N rate increased, but each cultivar had a different response to different rates of nitrogen. Dashtestan and Zarghan had superiority over Darab 14 with respect to overall agronomic properties such as response to fertilizer and early maturity, but from the qualitative point of view, Darab 14 produced higher percentage of oil.
M Modares Sanavi, M Amini Dehagh, M Gholamhoseni, M Panj Tan Dost,
Volume 13, Issue 48 (7-2009)
Abstract
In order to study the effect of air and root-zone temperature on yield, yield components, nodulation and nitrogen fixation of three annual medics, an experiment was conducted in controlled environment (growth chamber) at the Faculty of Agriculture, Tarbiat Modares University in 2006. The experiment was performed as a spilt split plot with the layout of completely randomized design with three replications. Air temperature at three levels including 15/10, 20/15 and 25/20ºC day/night, four levels of root-zone temperatures including 5, 10, 15 and 20ºC and three annual medics (Medicago polymorpha, M. radiata and M. rigidula) were randomized to main plot, sub plot and sub sub plot units, respectively. The results showed that there were significant differences among annual medics for dry matter production, yield components and nitrogen fixation. M. rigidula produced more leaves, stems and root dry matter, leaf and stem to root ratio, leaf number and area and forage yield than other annual medics. Also, three annual medics at 25/20ºC day/night air temperature (the highest one) produced more nodulation dry matter (8.85 mg/pot) and nitrogen fixation (7.7 mg/g dry matter) than other temperatures. Plants at the former temperature produced 8 and 2 times more nodulation and nitrogen fixation than 15/10ºC day/night air temperature (the lowest one), respectively. Low root-zone temperature up to 5ºC had severely negative effect on yield and nitrogen fixation in the three studied annual medics. Interaction among annual medics, air and root-zone temperatures showed that M. rigidula was better than other annual medics for yield, nodulation and nitrogen fixation at 25ºC air temperature and 15ºC root-zone temperature . The result showed that M. rigidula had normal growth and development compared with other annual medics at low root-zone temperatures. Thus, M. rigidula may be a better annual medic for cultivation in cold and moderate regions. Therefore, in the zones where soil temperature is lower than 5ºC during the season, cultivation of annual medics is not successful, but in the zones where soil temperature is greater than 10ºC, annual medics have normal growth and produce average yield due to better nitrogen fixation.
M Malakouti, M Babaakbari, S Nezami,
Volume 13, Issue 49 (10-2009)
Abstract
To increase grain yield, nitrogen use efficiency (NUE) and nitrogen apparent recovery fraction (NARF) in wheat (Triticum aestivum L.), an experiment was carried out in Karaj Soil and Water Research Station farm for two consecutive growing seasons in 2004-05 and 2005-06. The experimental design was RCBD with 6 treatments (T1= Control T2= 150 kg ha-1 of N as urea in 3-split applications T3= 1/3 N as SCU as the base fertilizer + 2-split urea applications T4= 150 kg ha-1 N as SCU as the base fertilizer T5=150 kg ha-1 of N as urea in 2-split applications and T6=1/3 N as complete fertilizer as the base fertilizer +2-split urea applications) in the first year and 7 treatments (T1= Control T2= 180 kg ha-1 of N as urea in 2-split applications T3= 180 kg ha-1 of N as urea in 3-split applications T4= 180 kg ha-1 N in 5-split urea applications T5 = pre-plant urea + 4-split urea applications T6= 1/3 N as SCU as the base fertilizer +4-split urea applications and T6=1/3 N as complete fertilizer as the base fertilizer +4-split urea applications) in the second year with 3 replications. In the second year, N rate was increased from 150 to 180 kg ha-1, adding the existing extra nutrients in complete macro and fertilizers to other treatments and N split-application was increased up to four times. After harvesting, grain yield, NUE and NARF were measured. The results of first year revealed that the yield, NUE and NARF for T2 (5145 kg ha-1, 13.8 kg kg-1, 41.2%, respectively) and T6 (5067 kg ha-1, 13.2 kg kg-1, 38.2.2%, respectively) were increased significantly at 1% level. In the second year, the maximum grain yield (6335 kg ha-1), NUE (16.2 kg kg-1) and NARF (50%) were obtained again from T6 treatment. Higher yield, NUE and NARF in the second year were mainly due to higher N rates and more N split applications. The economic returns for these substitutions, even without considering any fertilizer subsidies, the averages turned out to be 14, 8 and 4 in these treatments, respectively. Overall results revealed that the substitution of complete macro and SCU fertilizers with pre-plant urea is advisable in wheat production areas. Therefore, it is recommended that the experiment be further tested and evaluated in some wheat growing provinces.l results.
N Ghanavati, M Malakouti, A Hossein Por,
Volume 13, Issue 49 (10-2009)
Abstract
Correlation between components of Q/I and wheat (Triticum aestivum L.) growth indices was studied in a greenhouse experiment during 2003-04 growing season. Eighty soil samples (0 – 30 cm depth) were collected randomly in farms around the Abyak region, Ghazvin province. Twenty-one samples were then selected based on soil texture and NH4OAC-K. The research included treatments of 21 soils and two potassium (K) levels (0, 100 mg/kg) and was conducted in a factorial manner in a randomized complete block design with three replications for studying correlations between Q/I and treatments. Effect of potassium application on the wheat growth was found to be significant at 5% level. The effect of soil properties on wheat growth was also found to be significant at 1% level. However, the interaction of K and soil was not significant. There were no significant differences among the different equilibrium time intervals. The soil potassium buffering capacity (PBCK) values were strongly correlated with CEC (r =0.996**), clay content (r = 0.921**) and moisture saturation percentage (r = 0.811**). Final equation derived from stepwise regression for prediction of PBCK was as follows: PBCK = 7.419 CEC –19.743 R2adj = 0.782** The equilibrium potassium activity ratios (ARke) were strongly correlated with soluble potassium (r =0.846**), NH4OAC-K (r =0.730**), SP (r = 0/794*), OC (r = -0.477ns) and clay content (r=-0.602*). Similarly, readily exchangeable potassium (ΔK0) was strongly correlated with ammonium acetate extractable potassium (r = 0.871**), soluble potassium (r = 0.778**), saturation percentage (r = 0.551*), organic carbon percentage (r=-0.045ns) and clay content (r=-0.206ns). There was no significant correlation between ΔK0 and ARKe with potassium uptake values by wheat. In contrast, there was a strong correlation between PBCK values and potassium uptake by wheat (r = 0.729**), and relative wheat yield (r = 0.735**). There was no significant correlation between Q/I parameters when KCl and K2SO4 were used, and the soil physicochemical properties. However, Q/I parameters obtained from KCl showed a higher correlation with wheat plant's growth indices.
N Nourmahnad, M Emamzadei, B Ghorbani, A.r Mohamdkhani,
Volume 13, Issue 50 (1-2010)
Abstract
Water scarcity causes production losses in arid and semi arid regions. In this condition, deficit irrigation is one of the most important methods to minimize effects of water shortage. This research was conducted to evaluate the effects of two kinds of irrigation management (deficit irrigation and partial rootzone drying technique) on some of physiological and phenological characteristics and water use efficiency of tomato. The experiment was carried out in a completely randomized design with five treatments and four replications. The treatments consisted of DI75 and DI50 (supplying 75% and 50% water requirement) applied to the whole root system, PRD75 and PRD50 (supplying 75% and 50% water requirement) which was applied to one side of the root system, and alternated in every irrigation, and FI treatment, which supplied 100% water requirement, and was considered as control. The results showed that the highest water use efficiency was observed in PRD75 (6.28 kg/m3) and the lowest in DI50 (1.98 kg/m3). Water use efficiency was reduced 67% in DI50 and increased 4.6% in PRD75, as compared with full irrigation. Furthermore, plant water state showed that relative water content was higher in PRD treatments than DI treatments. The analysis of variance indicated that there was a significant difference in leaf diameter stomata among treatments at 5% level .The higher level of water increased stomata diameter. The opening of stomata in FI and DI treatments was higher than PRD treatments. FI had the highest numbers of stomata per unit of leaf area and PRD50 had the lowest (10509.04 and 6904.4, respectively). There was no difference among treatments in phenological characteristics in terms of growing degree-day to fruit yield and growing-degree day to harvesting.
Atlassi Pak, Nabipour , Meskarbashee ,
Volume 14, Issue 51 (4-2010)
Abstract
Gray mold, caused by Botrytis cinerea, is a serious disease of cut rose flowers (Rosa hybrida L.) in Iran. In order to elucidate the effects of different potassium and calcium levels in nutrient solution on susceptibility of cut rose flowers to gray mold, this experiment was carried out as factorial design in a randomized complete block with four replications at Safi Abad Agricultural Research center in 2008 for one year. In this experiment, rose plants were grown and subjected to three levels of potassium (1.0, 5.0 and 10.0 mM) in combination with two levels of calcium (1.6 and 4.8 mM) under hydroponic condition. Rose flowers from two consecutive harvesting periods were sprayed with the conidial suspension (104 spore/ml) of B. cinerea isolate. At the end of experiment the disease severity was recorded and analyzed. The results indicated that application of 10.0 mM K in the nutrient solution led to increasing rose disease severity to gray mold (30.4 % day-1) compared to 1.0 mM (24.8 % day-1) and 5.0 mM (26.2 % day-1) of K levels (P< 0.01). The increased susceptibility was associated with a decreased concentration of Ca in the rose petals. Correlation analysis revealed that susceptibility of rose flowers to gray mold significantly increased with K to sum cations ratio in the nutrient solution (r = 0.94*). The increase of Ca supply from 1.6 to 4.8 mM resulted in decline of disease severity from 29.6 to 24.6 % day-1 (P< 0.01). Therefore, balanced application of potassium and calcium (5.0 and 4.8 mM, respectively) is recommendable for preventing antagonistic effects between them and reducing of rose gray mold intensity under hydroponic conditions.
A Jalali, M Galavi, A Ghanbari, M Ramroudi, M Yousef Elahi,
Volume 14, Issue 52 (7-2010)
Abstract
Using treated wastewater led to increasing crop yield, but it may causes heavy metals accumulations and also their toxicity in soil and plant. In order to investigate the effects of wastewater on yield, forage yield components, and heavy metals concentrations in stem and leaf of sorghum, an experiment was conducted in the agricultural Research Institute of Zabol University in 2006-2007, using a randomized complete block design with four replication. The irrigation treatments were: 1) well water for whole growing season as control (T1), 2) well water for all growing season along with NPK application (T2), 3) wastewater during the first half of growing season (T3), 4) wastewater during the second half of growing season (T4), 5) wastewater and tapwater alternately (T5) and 6) wastewater for whole growing season (T6). The results showed that irrigations with wastewater and well water alternately and wastewater for whole growing season produced the maximum forage yield and the maximum heavy metal accumulation in plant organs observed by irrigation with wastewater for hole growing season, and wastewater and well water alternately. There was significant increase between T5 and T6 relative to control and other treatments. The elements concentration such as Cu, Pb and Fe in leaf was more than stem, but Zn and Ni concentration in stem were more than leaves. There were no significant differences for Mo and Cr concentration between stem and leaf. Forage yield in T6 and T5 relative to T2 were increased 38.96 and 51.95 percent respectively. In all irrigation treatments the amount of elements and heavy metals in sorghum were lower than standard limits. Based on the results, alternative irrigation method (T5) is recommended for forage sorghum production.
M Bashiri Seghale, S.h.r Sadeghi, A.s Rangavar ,
Volume 14, Issue 52 (7-2010)
Abstract
Erosion plots are basically used for studying erosion processes and many related problems. However, the possibility to extend the results of experimental plots to surrounding watersheds is rarely taken into account. In the present study, an attempt was made to study on the accuracy of soil erosion plots in estimation of runoff and sediment yield from small watersheds. Towards this attempt, 12 experimental plots with length of 2, 5, 10, 15, 20 and 25 meter were installed on two north and south facing slopes in Sanganeh watershed, northeastern Razavi Khorasan Province with an area of ca. 1 ha. The performance of the plots in estimation of runoff and sediment was controlled by data collected at the main outlet associated with 12 storm events occurred during November 2006 to June 2007. The results showed that the accuracy of plot estimates on sediment and runoff improved while the plot length increased. The optimal length for estimation of sediment and runoff parameters was found to be equal to average slope length and more than 20m.
J. Zamani Babgohari , M. Afyuni , A. H. Khoshgoftarmanesh , H. R. Eshghizadeh2 ,
Volume 14, Issue 54 (1-2011)
Abstract
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.
Gh. Omidi Ardali , M. J. Bahrani,
Volume 15, Issue 55 (4-2011)
Abstract
The optimum levels of soil moisture and nitrogen are important to obtain higher yields. To investigate the effects of water stress, nitrogen levels and application times on yield and yield components of sunflower (Helianthus annuus L.), the cultivar Euroflor at different growth stages, a two year study (2006-007) was conducted at Research Fields of College of Agriculture, Shiraz University (Badjgah) using a split factorial design with four replications. Treatments were water stress at three levels, (non-stress and stress at flowering and seed formation) as main plot and three N levels (0, 70, 140 kg ha-1) and N application times (split application at planting and stem elongation, planting and heading, and stem elongation and heading) as subplot. Number of seed per head, 1000-seed weight, seed yield, Oil yield and HI were measured. Results showed that the effects of water stress and N rates on yield and yield components were significant, but the effects of N application times and interaction between water stress, nitrogen rates and application times were insignificant. Overall, the crop showed more sensitivity to drought stress at flowering time, and 70 kg N ha-1 is recommended for the region.
R. Taghizadeh, R. Seyed Sharifi,
Volume 15, Issue 57 (10-2011)
Abstract
In order to evaluate the effects of nitrogen fertilizer levels on grain yield and nitrogen use efficiency in corn cultivars, a split plot experiment based on randomized complete block design with three replications was conducted at the Research Farm of Islamic Azad University of Ardabil during 2006-2007 cropping seasons. Factors consisted of nitrogen fertilizer at four levels (0, 80, 160 and 240 kg/ha) and corn cultivars at three levels (SC-310, SC-404 and DC-370). The results showed that grain yield was significantly affected by nitrogen levels, corn cultivar and nitrogen level × corn cultivars. The highest grain yield was related to application of 240 kg/ha nitrogen with SC-404 cultivar. Nitrogen levels of 160 and 240 kg/ha had similar yields, but more yield than 80 kg/ha. With increasing of nitrogen levels, plant height, the number of grains per ear rows significantly increased. Comparisons of means showed that increasing the application of nitrogen fertilizer decreased nitrogen use efficiency. Nitrogen use efficiency decreased from 17.13 kg/kg with application of 80 kg/ha nitrogen fertilizer to 12.4 kg/kg in application of 240 kg/ha nitrogen fertilizer. Nitrogen use efficiency was affected by corn cultivar. Nitrogen use efficiency in SC-404 was higher than SC-301. In conclusion, in order to increase grain yield and nitrogen use efficiency, SC-404 hybrid should be applied with 160 kg N/ha in climatic conditions of Ardabil Plain.
M. Rabiee, M. Kavoosi, P. Tousi Kehal,
Volume 15, Issue 58 (3-2012)
Abstract
To determine the proper nitrogen fertilizer rates and its application times for achieving high grain and oil yields of rapeseed cultivar, Hyola 401, a research was carried out in paddy fields of Rice Research Institute of Iran in Rasht during two cropping seasons. A factorial experiment was conducted in a completely randomized block design with three replications. The experimental factors were pure nitrogen fertilizer rate at five levels of 0, 60, 120, 180 and 240 Kg ha-1 and fertilizer application times at five levels of all fertilizer at planting 1/3 at planting + 2/3 in stem elongation 1/3 at planting + 1/3 in stem elongation + 1/3 before flowering 1/3 in 3-4 leaf stages + 1/3 in stem elongation +1/3 before flowering 1/4 at planting + 1/4 in 3-4 leaf stages + 1/4 in stem elongation + 1/4 before flowering. The results of statistical analyses showed that from amony nitrogen rates, application of 240 Kg N ha-1 and 180 Kg N ha-1 with average production of 2505 Kg ha-1 and 2596 Kg ha-1 respectively showed the highest grain yield and were in the same group. of Nitrogen application times, application of 1/3 at planting + 1/3 in stem elongation + 1/3 before flowering had the highest grain and oil yields with average of 2155.3 Kg ha-1 and 9865 Kg ha-1, respectively. Maximum oil percentage was observed in control treatment (without N-fertilizer application) and the highest oil yield was obtained for nitrogen rates of 180 and 240 Kg ha-1. Also, the highest growth period was observed for the treatment of 240 Kg nitrogen with 206.3 days. The results showed that nonsignificant difference exists between the nitrogen rates of 180 and 240 Kg ha-1 in grain and oil yields. Therefore, the rate of 180 Kg ha-1 is recomended due to less fertilizer consumption and prevention of destructive effect on the environment
R. Bagheri, Gh. Akbari, M. H. Kianmehr, Z. Tahmasebie Sarvestani,
Volume 16, Issue 59 (4-2012)
Abstract
To evaluate the effect of nitrogen slowly released from pellet, composed of manure and urea fertilizer on the Nitrogen efficiency and morphological Characteristics and grain yield of corn hybrid (S.C704), a field experiment was carried out in Aboureihan research farm of Tehran University in 2009. The factorial design of the study comprised a randomized complete block with three replications. The application rates of N at four levels (46, 92, 138 and 184 kg N. ha-1) and two levels by methods of N distribution (pellet and mixed with soil) were applied. In this research, a Screw Extruder setup was designed and manufactured. Statistical analysis indicated that NUE, as well as agronomic efficiency (AE) was reduced while physiological efficiency (PE) increased with increasing N rates. Also, most plant length and stem diagonal and cob diagonal pellet belonged to the treatment. But, the number of leaves per plant did not affect the distribution method of fertilizer.The results showed significant differences among various rates of nitrogen and methods of N distribution considering grain yield and grain protein. The higher rates of N increased grain protein, grain yield and yield components (except for number of rows per ear). Maximum grain yield (11.1 t. ha-1) was obtained with 184 kg N. Ha-1 treatment.
Y. Habibzadeh, M. R. Zardoshti, A. Pirzad, J. Jalilian,
Volume 16, Issue 60 (7-2012)
Abstract
To evaluate effect of different irrigation regimes and mycorrhizal fungi on the growth and yield of mungbean NM92 [Vigna radiata (L.) Wilczk], a field experiment was conducted in split plot arrangements using randomized complete block design (Irrigation after 50, 100, 150 and 200 mm evaporation from pan class A as main plots and mycorrhiza species, Glomus mosseae, G. intraradices and a non-inoculated treatment as sub-plots) with three replications at the Research field of Urmia university in 2009. Results showed that irrigation after 50mm evaporation from pan class A, and plant inoculated with G. intraradices produced the highest grain yield (1678.5 kg/ha and 1537.6 kg/ha, respectively), total dry weight, leaf dry weight, leaf area index, crop growth rate, relative growth rate and net assimilation rate. In Contrast, irrigation after 200 mm evaporation from class A pan and non-inoculated treatment produced the lowest grain yeild (1159.2 and 1301.9 kg/ha, respectively). Reducing the irrigation distance led to an increase in total dry weight, leaf dry weight, leaf area index, crop growth rate, relative growth rate and net assimilation rate. Despite lower grain yield in water deficit condition, AM fungi inoculation significantly reduced the effect of stress on grain yield. All inall, both mycorrhizae species significantly (P 0.05) increased the grain yield of mungbean under well-watered and water deficit conditions
M. J. Fereidooni, H. Farajee, H. R. Owliaie, E. Adhami,
Volume 16, Issue 60 (7-2012)
Abstract
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.
S. Jafari, Z. Iranshahi , Gh. Fathi, S. A. Syadat,
Volume 16, Issue 61 (10-2012)
Abstract
Cadmium is a toxic element in plant nutrition and is considered as a contaminant of food and feed. A greenhouse experiment was carried out to examine the effects of combined application of cadmium and zinc on responses of wheat on a clay loam soil texture. This experiment was designed in a factorial experiment with randomized complete block design (RCBD) and four replicates per treatment. Three levels of cadmium (Cd 0, Cd 50 and Cd 100 mg kg-1) and three levels of zinc (Zn 0, Zn 50 and Zn 100 mg kg-1) were added to the pot in factorial(9 treatments), and then Chamran seed variety of wheat (triticum aestivum L.) was planted in each pot. The statistical analyses showed that Cd application significantly (P0.01) decreased grain, straw, and total yield, but Zn application increased these parameters significantly (P0.01). Application of Cd separately decreased the grain yield by 61.5 while application of Zn separately increased the grain yield by 36.9. Cd application increased the Cd concentration and uptake by grain and straw as well as total uptake but by increasing Zn application, Cd uptake was decreased by wheat. Cd concentration was higher in straw than that grain, but Zn showed a different trend. Decreasing Zn applications decreased total uptake of Cd from 42.9 in Zn0 to 7.8 mg kg-1 in Zn100 treatment. Although this soil was very calcareous, this characteristic did not control Cd absorbtion.
A. Talebi, A. H. Charkhabi, H. R. Peyrowan, A. A. Hashemi, H. Mosaddegh,
Volume 16, Issue 62 (3-2013)
Abstract
The Marls are unstable sedimentary formations that contain chemical materials and destructive particles. Marls Erosion processes are very intensive, so different forms of erosion on the marls as badlands are of specific characteristics in marl lands. Hence, recognition of effective characteristics in marls erodibility is necessary to adopt corrective measures and methods. In this research, for assessing marls erodibility in Hablehroud watershed portable rain simulator was used. Runoff and sediment amounts were measured in each marl unit. Then effective Factors were identified using statistical parameters. Finally, by factor analysis we determined the relationship between marls chemical properties and sediment yield. Therefore, effective parameters of erosion and sediment yield were determined. Results showed sediment yield is decreased in gypsum marl, sandy marl, salt marl and limy marl. In addition, erosion and sediment yield are increased with increasing EC, Na, Cl, SAR and with decreasing TNV, HCO3
R. Asadi, F. Hassanpor, M. Tabatabaei, N. Koohi,
Volume 17, Issue 63 (6-2013)
Abstract
Application of the modern irrigation systems such as T-Tape irrigation system is one of the ways to achieve aptimal irrigation The present study deals with the effect of surface and subsurface drip irrigation systems on the cotton yield For this purpose, a field experiment was conducted in the Agricultural and Natural Resource Research Institute of Orzoueyeh, located in the Kerman province. The experiments were conducted in a split plot design based on the Randomized Complete Block Design (RCBD) with three replications. The treatments were comprised of three levels of the crop water requirements (i.e. irrigation based on 100, 80 and 60 percent of crop water requirement) in main plot and with the two irrigation systems, surface one and subsurface one. The results showed that the yield resulting from treatments with 60 and 80 percent crop water requirement was respectively 981 and 413 kg/ha lower than that of treatment with 100 percent crop water requirement. In addition, the obtained yield due to subsurface system was 248 kg/ha greater than that of the surface pattern. The interaction of treatments on the yield of the crop also indicates that the treatment with subsurface system and 100 percent crop water requirement produces the maximum yield. Despite equal water consumption in each sub plots, the WUE in subsurface system was 14 percent higher than that of surface system. From the economical point of view, benefit to cost ratio in the subsurface system is 8 percent less than surface system. Considering the results obtained in this study in the light of water saving as the main objective in deficit irrigation and water use efficiency (WUE) for cotton cultivation in Orzoueyeh, the 80% of crop water requirement is preferred
