Sina Fallah; razieh kakolvand; ali abbasi
Abstract
Increasing water use efficiency (WUE) is one of the most important strategies for mitigating water deficiency crisis. The aim of this study was to investigate the effect of plant competition on water use efficiency of intercropping under different moisture regimes. The experiment was a ...
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Increasing water use efficiency (WUE) is one of the most important strategies for mitigating water deficiency crisis. The aim of this study was to investigate the effect of plant competition on water use efficiency of intercropping under different moisture regimes. The experiment was a split–split-plot design with three replications. The main plot consisted of three levels of soil moisture including W1: full irrigation, W2: mild stress (irrigation on the basis of 75% W1), W3: severe stress (irrigation on the basis of 75 % W1). The subplot contained five planting patterns: fenugreek sole crop, nigella sole crop and three mixed ratios (2:1, 1:1, 1:2 of fenugreek and nigella). Results showed that the greatest WUE for seed production (WUEs) was obtained in fenugreek: nigella (1:2) treatment under drought stress conditions. Under mild stress conditions, the WUEs in fenugreek: nigella (1:2) treatment was even higher than nigella sole crop under no stress conditions, under which the highest WUE for biomass was observed in fenugreek: nigella (1:2) and (2:1) treatments and the lowest level was in nigella sole crop. The water equivalent ratio (WER) of intercropping treatments was superior to each of the sole crops of fenugreek and nigella. Under mild stress conditions, the maximum level of WER in fenugreek: nigella (1:2) and (2:1) treatments was 1.44 and 1.47, respectively. It can be concluded that interspecies competition is one of important strategies to increase the WUE and production under drought stress conditions.
f g; s f; a t
Abstract
The trend of saline water utilization in agricultural production is increasing. In order to evaluate the effect of source and rate of nitrogen on physiological characteristics of purslane (Portulaca oleracea L.) irrigated by saline water, a factorial experiment was conducted in a completely randomized ...
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The trend of saline water utilization in agricultural production is increasing. In order to evaluate the effect of source and rate of nitrogen on physiological characteristics of purslane (Portulaca oleracea L.) irrigated by saline water, a factorial experiment was conducted in a completely randomized design with three replications in the greenhouse conditions. Treatments included five levels of saline water (distilled water as the control, natural saline water with EC of 2.2 dS/m, three levels of saline water prepared by addition of NaCl (2.2, 4.4, and 6.6 dS/m) and four levels of fertilizer (control, 40, 80, and 120 g/kg soil) in the form of poultry manure and chemical fertilizer. The results showed that an increase in salinity increased chlorophyll a and chlorophyll b and then decreased them at 6.6 dS/m. An increase in salinity levels increased the amount of sodium and decreased the amount of potassium. The maximum amount of chlorophyll a and chlorophyll b were observed with 4.4 dS/m treatment. The interaction of salinity level × nitrogen source × nitrogen rate was not significant for any of the measured parameters. Results of poultry manure were better than those of chemical fertilizer, because chlorophyll content, soluble sugar, proline, sodium, and potassium in purslane plant were higher. Thus, the plants fertilized with poultry manure or those irrigated with natural saline water experienced salinity stress, but their higher uptake of potassium alleviated the stress effects and made it tolerable for the plant.
Sina Fallah; m ghobadinia; m shokrgozar; sh ghorbani
Abstract
Population growth has resulted in increase in water use, which in turn has led to a decline in quantity and quality of groundwaters. Therefore, quantitative and qualitative assessment of groundwater resources is crucial for sustainable agriculture. This research was conducted to evaluate the spatio-temporal ...
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Population growth has resulted in increase in water use, which in turn has led to a decline in quantity and quality of groundwaters. Therefore, quantitative and qualitative assessment of groundwater resources is crucial for sustainable agriculture. This research was conducted to evaluate the spatio-temporal variation (18 years) of groundwater table and the quality of groundwater resources of Darab plain. To this end, data of 39 piezometers in the plain were selected to evaluate the groundwater table fluctuations during an 18-year period, while qualitative characteristics were determined for 2008-2012. Results showed that the mean groundwater level depletion was 27.23 m during the studied period. Also, qualitative dynamics indices of water showed that EC, pH, and nitrate of the groundwater increased annually during the study period. Overall, the water budget of the region, the lowering of water table, and the increase in water salinity and acidity indicate the unsustainability risk of the ground water of the studied region.