Elham Madadi; Seyfollah Fallah
Abstract
Introduction: Drought stress is one of the most important limiting factors for plant growth in the arid and semi-arid regions. This stress affecting crop production such as maize (Zea mays L.). Maize can play an important role in providing forage for silage animals, especially in the winter season in ...
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Introduction: Drought stress is one of the most important limiting factors for plant growth in the arid and semi-arid regions. This stress affecting crop production such as maize (Zea mays L.). Maize can play an important role in providing forage for silage animals, especially in the winter season in most parts of Iran due to high production capability . The application of plant growth regulators such as jasmonic acid and humic acid is one of the fastest ways to increase crop tolerance to environmental stresses viz. drought stress. The role of these acids is to prevent aging and falling of leaves, hormonal effects and improve nutrient uptake, which leads to increase of root and shoot biomass. Due to the expansion of industrial livestock, maize silage supply is essential. On the other hand, maize pollination and grain filling occur in the summer season and it overlaps with the peak of water limitation. Thus, in this experiment, the effect of jasmonic acid and humic acid on morpho-physiological characteristics and water use efficiency of forage maize under drought stress were studied.
Materials and Methods: In order to investigate the effects of jasmonic acid and humic acid to mitigate the impact of drought stress during pollination of forage maize (KSC 704), an experiment was conducted in research farm of the Shahrekord University, in 2016. The experiment was performed as a split plot in a randomized complete block design with three replicates. The treatments consisted of different levels of drought stress (no drought stress (field capacity), moderate drought stress (0.75 field capacity) and severe stress (0.50 field capacity)) as main plots and plant growth regulators (without hormone, jasmonic acid and humic acid) as sub plots. In no hormone condition, distilled water was used. Foliar application was done 10 mM jasmonic acid and humic acid content of 1500 grams per hectare before maize flowering. The volume of water consumed for each irrigation was measured by contour system. In this experiment leaf relative water content (RWC), proline, chlorophyll content, carotenoids, leaf area index (LAI), leaf weight, stem weight, ear weight, forage yield and water use efficiency (WUE) were measured. The analysis of data was performed using SAS software. Mean comparisons of study characteristics were done by LSD test at the 5% probability level.
Results and Discussion: The results showed that the relative water content, proline, chlorophyll, carotenoids, leaf area index, shoot weight, ear weight, forage yield and water use efficiency were affected by drought stress conditions. Although drought stress was reduced forage yield and related traits, the use of jasmonic acid compared to the control and humic acid under mild stress was significantly increased relative water content (61.1 and 39.3 %, respectively), leaf weight (60.4 and 41.8%, respectively), stem (14.8 and 25.12%, respectively), ear weight (13 and 23.8%, respectively), proline content (16 and 32.1 %, respectively), forage yield (24.4 and 24.2%, respectively). Under severe stress conditions, jasmonic acid significantly increased relative water content of leaf, weight of leaf, weight of stem and leaf area index. Under severe drought stress, jasmonic acid and humic acid had no significant difference. It was observed that under non-stress conditions, jasmonic acid wasn’t effective on water use efficiency and humic acid showed a negative effect. Under moderate drought stress, jasmonic acid was effective with increase 21.15 %, in moderating drought stress for maize and under severe stress jasmonic acid and humic acid had no significant effect.
Conclusion: According to the results, the occurrence of drought stress during pollination has a significant effect on maize yield. So that the severe drought stress (50% soil moisture depletion) leads to decrease in yield of maize forage due to decrease weight of leaf and ear. Although the most positive results of the use of growth regulators on maize yield were obtained under non-stress (full irrigation), the effect of moderate drought stress was mainly observed on forage production on jasmonic acid. The positive effect of foliar application of jasmonic acid in reducing the damage of drought stress and increasing of water use efficiency under moderate drought stress indicated that the use of this hormone could be useful in increasing production and quality of maize silage.
Marjan Nekokhoo; Seyfollah Fallah; Rahim Barzegar
Abstract
Introduction: Water resources are very limited for agricultural production. Therefore, optimal use of available water resources and increased water use efficiency in agriculture are necessary. Application of poly ethylene mulch is one of the approaches that can be effective in increasing water use efficiency. ...
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Introduction: Water resources are very limited for agricultural production. Therefore, optimal use of available water resources and increased water use efficiency in agriculture are necessary. Application of poly ethylene mulch is one of the approaches that can be effective in increasing water use efficiency. The water deficient trend is increasing in agricultural lands of the Iran and, on the other hand, the yield components of hull-less seed pumpkin are sensitive to drought stress. Therefore, the aim of this study was to determine the effect of transparent polyethylene mulch on the performance and water use efficiency of hull-less seed pumpkin under different irrigation rates.
Materials and Methods: This experiment was carried out in the central part of Isfahan, Northern Baraan (320 and 32/N, 510 and 52/ E, and 1534 m above sea level) in a randomized complete block design with three replications, during 2016. Treatments consisted of full irrigation+ poly ethylene mulch (M+FW), 0.75% full irrigation+ poly ethylene mulch (M+0.75FW), 0.50% full irrigation+ poly ethylene mulch (M+0.5 FW), and full irrigation without mulch (FW). In April, the cultivation operations include mechanical planting, mulch were done. The spacing of the rows was 150 cm and the spacing between plants was 70 cm. The irrigation was applied until the plant was fully established and then drought stress was begun based on above irrigation treatments. The studied traits were number of fruits per plant, average fruit weight (kg), fruit yield (ton ha-1), number of seeds per fruit, fruit diameter (cm), 1000 grains weight (g), grain yield (kg ha-1), water use efficiency (kg m-3), oil content (%) and oil yield (kg ha-1). Statistical analysis was performed using SAS software and comparisons of the means were made using the least significant difference (LSD) test at the 5% probability level.
Results and Discussion: The highest number of fruits per plant belonged to M+FW treatment (with an average of 3.22) and the lowest was recorded in M+0.5FW treatment (with an average of 2.44). This difference between treatment FW and M+0.75FW can be due to the high moisture under the poly ethylene mulch. The highest fruit weight (3.60 kg) was obtained in M+FW treatments, which had a significant difference with other treatments. The difference weight of fruit in M + FW treatment was 14% compared to FW irrigation treatments. The highest fruit yield (95.72 ton ha-1) belonged to M+FW treatment and the lowest one (79.78) belonged to M+0.5FW treatment. The difference in fruit yield in M+0.75FW compared to FW treatment was 6%, but it was not significant. The number of seeds per fruit in M+0.75FW compared to FW and M+0.5FW treatments showed a difference of 13% and 17%, respectively which they were significant only with M+0.5FW treatment. With increasing drought stress, the amount of photosynthetic assimilate decreased, which reduced the number of seeds per fruit. The highest 1000 grains weight (173.13 g) belonged to M+FW treatment and the lowest one belonged to M+0.5FW (156.18 g). 1000 seeds weight in FW treatment was not significant compared to M+0.75FW treatment. Drought stress during plant development decreased the leaf area index in the plant. Application of plastic mulch reduces the effect of drought stress on leaf growth and its photosynthesis by decreasing water loss by evapotranspiration and transpiration. The difference grain yield between two treatments M+0.75FW with FW was 7% and this difference was not significant. Only significant difference was observed among M+0.5FW treatment with other treatments. The effect of different levels of moisture on water use efficiency was significant at 1% probability level. The highest water use efficiency was recorded in M+0.5FW treatment and the lowest was recorded in FW treatment. The difference in water use efficiency between M+0.75FW with full irrigation (FW) was 0.99 kg m-3, which was significant. Difference in water use efficiency between M+FW and FW was not significant for water use efficiency. The use of plastic mulch reduced water loss throughout the plant growth period and significantly increased water use efficiency. There was a significant difference among M+FW, M+0.75FW and FW for oil content. The highest and lowest oil contents belonged to M+FW and M+0.5FW, respectively. The maximum oil yield (558 kg ha-1) belonged to M+FW and the lowest one (412 kg ha-1) was obtained in M+0.5FW.
Conclusion: Transparent plastic mulch under water stress conditions can reduce the effect of drought stress on hull-less seed pumpkin by preserving water and other beneficial effects, including weeds reduction. Therefore, the use of this type of mulch is recommended for the cultivation of hull-less seed pumpkin in the central areas of the country facing the water crisis.
S. Fallah; Fayez Raiesi
Abstract
The effects of organic and inorganic N sources on nutrient (N and P) efficiency under the water-stressed conditions have not yet been determined. Thus, a field study was conducted to determine the influence of N from different sources along with drought stress on nutrient efficiencies of maize. Main ...
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The effects of organic and inorganic N sources on nutrient (N and P) efficiency under the water-stressed conditions have not yet been determined. Thus, a field study was conducted to determine the influence of N from different sources along with drought stress on nutrient efficiencies of maize. Main plots consisted of two irrigation treatments (i.e., optimum irrigation and cut-off irrigation at silking stage for two weeks), and subplots comprised N fertilizers (cattle manure: 40.8 Mg ha-1, poultry manure: 13.3 Mg ha-1, urea fertilizer: 435 kg ha-1, cattle manure + urea fertilizer: 20.4 Mg ha-1and 20.4 Mg ha-1, respectively) and control (without fertilizer). Results indicated that the imposition of water deficit and fertilizer type had a significant effect on N uptake while P uptake was significantly affected only by fertilizer type. The highest N and P uptake were obtained with poultry manure. Similarly, significant differences in N and P use efficiency and N physiological efficiency were observed between the water deficit and fertilizer type (P
M. Fereidooni Naghani; F. Raiesi; S. Fallah
Abstract
Abstract
The addition of manures and chemical fertilizers as soil amendments for the improvement of soil fertility and quality could affect the seasonal changes in the activity of soil microbes and enzymes. This study aimed at investigating the effect of different levels of nitrogen from broiler litter ...
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Abstract
The addition of manures and chemical fertilizers as soil amendments for the improvement of soil fertility and quality could affect the seasonal changes in the activity of soil microbes and enzymes. This study aimed at investigating the effect of different levels of nitrogen from broiler litter and urea sources on the trend of urease, alkaline phosphatase and saccharase activities in a clay loam calcareous soil cultivated with maize (Zea Mays L.) under field conditions. The treatments were a control (no fertilizer and broiler litter), 100, 200, 300 kg N ha-1 from broiler litter and 100, 200, 300 kg N ha-1 from urea, using a split-plot experiment arranged in a completely randomized block design with four replications. The activity of soil enzymes was monitored at five different stages after treatments imposition with 20-day intervals during the growth period. Results of this research show that the activity of urease, alkaline phosphatase and saccharase in broiler litter- and urea- treated soils were significantly greater than that in the control soil (no broiler litter and urea added). The level of broiler litter and urea fertilizers and time had a significant effect (P
S. Fallah; A. Ghalavand; D. Ghanbarian; A. Yadavi
Abstract
Abstract
Poultry manure contains considerable nutrients and its application to agricultural land may boost soil fertility. In order to study the effects of poultry manure and its incorporation method with soil on soil chemical properties, a field experiment was conducted at the Ecological Research Center ...
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Abstract
Poultry manure contains considerable nutrients and its application to agricultural land may boost soil fertility. In order to study the effects of poultry manure and its incorporation method with soil on soil chemical properties, a field experiment was conducted at the Ecological Research Center of Zagroos, 30 kms from northeastern of Khorramabad for two consecutive years (2004 and 2005). Treatments were arranged in a split plots layout based on randomized complete block design with four replications. Two incorporation methods of poultry manure incorporation with soil by furrower and disk+furrower as the main plot, and different amounts of broiler litter including zero, 10, 20 and 30 Mg ha-1 as subplot were considered. The results suggested that the phosphorus, zinc and cooper concentration as well as EC of soil were much greater in the disk+furrower treatment relative to the furrower treatment. However, the amount of total nitrogen and corn dry matter for the furrower treatment was significantly more than disk+furrower treatment. Averaged across years and incorporation method, maximum EC, organic matter, macronutrients and micronutrients concentration of soil and corn dry matter were obtained by applying 30 Mg ha-1 poultry manure. However, no significant differences were observed between 30 Mg ha-1 with 20 Mg ha-1 poultry manure for the EC, organic matter and potassium. The organic matter and concentrations of total nitrogen, phosphorus and micronutrients in soil for the second year were significantly greater than those for the first year. Results suggest that high rates of manure application are not sustainable and will lead to phosphorus accumulation and soil salinization. Thus, that incorporation of 20 Mg ha-1 poultry manure with soil by furrower might be appropriate for maintaining or increase of soil fertility and fairly corn production under conditions similar to this experiment.
Key words: Poultry manure, Manure incorporation method, Nutrients, Soil, Dry matter
