جستجوی مقالات مرتبط با کلیدواژه "پلیمر سوپر جاذب" در نشریات گروه "کشاورزی"

Acacia with the scientific name Acacia salicina is a tree or shrub from the leguminous family and a nitrogen fixer. This species is native to dry areas in southern Australia. In some areas, this species is used as a source of fodder for livestock, for ornamental purposes, and for revival areas without vegetation. Climate change is one of the most important concerns of the world's growing population. Drought is one of the most important abiotic stresses that affects the nutritional status of plants. Stresses constantly affect the growth and development of plants, which are considered the most important factors of yield reduction in the world. Stresses are the result of abnormal physiological processes that are caused by one or a combination of biological and environmental factors, and drought is one of the most important abiotic stresses that affect growth and performance, as well as this stress can cause plant death and limits approximately 25% of agricultural production. One of the most common ways to withstand drought stress is the use of super absorbent polymers. Commercial superabsorbent polymers are hygroscopic materials similar to sugar, and the shape of these polymers must be maintained after absorbing water and swelling. They don't have harm for soil, plants and environment. Considering the increase in temperature and pollution the purpose of this research is the effect of using three types of super absorbent polymers to increase N.P.K. absorption, water retention, reduce irrigation, reduce costs and improve the growth of acacia plants under drought stress conditions for cultivation in areas free of vegetation to contrast with fine dust in Khuzestan.

Materials and Methods:

 In order to improve the nutritional status of acacia, a research was conducted using three types of superabsorbent polymers in three concentrations at three levels of drought stress in a factorial format based on completely randomized block design with three replications in the agricultural faculty of Shahid Chamran University of Ahvaz.

The results showed that the use of superabsorbent polymers significantly increases the amount of nitrogen, potassium and phosphorus absorption by leaves, stems and roots. The concentration of 2 g/kg of A200 hydrogel in the first week increased leaf nitrogen by 12.85%, leaf phosphorus by 17.64%, stem nitrogen by 50.29% and root nitrogen by 4.96%. In the first week, SNF superabsorbent had the highest amount of potassium in stem and phosphorus in the root. Among the hydrogels, SNF superabsorbent polymer had the highest amount of phosphorus in the stem in the second week and a concentration of 1 g/kg, and this increase was significant compared to some treatments. The lowest amount of phosphorus in the stem were obtained s in the treatment of the first week and a concentration of 0 g/kg super absorbent polymer A200 and SNF. Increasing the concentration of super absorbent polymers increased the amount of phosphorus in the stem in most cases. Increase in the intensity

In order to study effect of super absorbent polymer application to mitigate adverse effects of nickel (Ni), a greenhouse experiment was conductedin Varamin, Iran during the growing season of 2016 in wheat. The experiment was installed in a completely randomized design, with treatments arranged in a factorial scheme with three levels of nickel (0, 60 and 120 mg per kg of soil) by three levels super absorbent polymer application (with out super absorbent polymer application (Control), 2 and 4 g per kg of soil), with three replicates. The results showed that nickel treatment significantly for all experimental traits. The nickel contamination caused a significant decreased plant height, total dry weight per plant and root dry weight per plant at by 8.51%, 31.52 and 56.06% respectively to control, Whereas, increased proline content, superoxide dismutase enzyme activity and the accumulation of nickel in leaves. Also the results showed that super absorbent polymer application increased plant height, total dry weight per plant and root dry weight per plant whereas, decreased proline content, superoxide dismutase enzyme activityand the accumulation of nickel in leaves. Generally the results of the present study indicate that super absorbent polymer application reduces the harmful effects of nickel stress and super absorbent polymer application treatment decreased oxidative stress in wheat plant.

IntroductionCommon millet (Panicum miliaceum L.) is a cereal plant cultivated for its grain, mostly in semi-arid regions of Iran. It is a warm-season and C4 grass with higher water use efficiency than C3 plants, short growing season, low moisture requirement, relatively high drought resistance and is capable of producing food or feed where other grain crops would fail. Water resources deficit and drought stress is becoming a major threat to plant productivity loss in agricultural systems therefore optimum use of limited water resources and seasonal scattered rainfall and water use efficiency is necessary. Drought stress leads to lower growth, yield and yield components in pearl millet. Super ab¬sorbent polymers have a great importance for their role in increase of absorption capacity and saving water in the soil and to combat water shortage conditions. The water holding capacity of super ab¬sorbent polymers helps to keep plants from sitting in water logged soil in times of excess moisture. Then, as moisture is needed, super ab¬sorbent polymers release moisture back into the root zone helping to maintain consistent soil moisture. Positive impact of super absorbent polymers on growth and yield of soybean and corn under water limited condition have been reported. The aim of this study was to evaluate the use of different levels of water deficit and super absorbent polymers on morphological and physiological characteristics of millet ecotypes.
Material and methodsThe experiment was carried out during spring and summer of 2013 in Faculty of agriculture research field of Shahid Bahonar University of Kerman (56º, 58'E; 30º, 15'N and 1754 m elevation). Soil type was a Sandy-loam, with pH 7.6 and mean annual precipitation of 150 mm. The experiment was carried out in a split plot arrangement based on RCBD design with three replications. Irrigation treatments included three levels: normal irrigation, drought stress with super absorbent application and drought stress were applied in main plots and Zahedan, Kahnooj, Ghale-ganj, Golbaf, p25 line and Pishahang Ecotypes as plant material were sown in sub plots. Irrigation intervals were conducted based on 50 and 100 mm evaporation from class A pan evaporation. Plants were harvested at the end of the growing season to determination of plant height, biological and grain yield. Ion leakage percent were measured based on method proposed by Zheng et al. (2008). Statistical analysis was done by MSTAT-C, Excel and SAS softwares and means were compared by Duncan’s multiple range test at 5% of probability level.
Results and discussionThe results showed that significantly increased were observed in stem length, grain and biological yield in super absorbent polymer application in comparison with the non-application in stress conditions. Stern et al. (1992) reported that the use of super absorbent polymers increased dry matter in wheat. The use of super absorbent decreased ion leakage that was consistent with the results of Harvey (2002). Pishahang cultivar had the higher biological yield in stress condition with super absorbent application compared to the other ecotypes of millet. Kahnooj ecotype in stem length and Ghale-ganj in grain yield significantly higher than the others. Kahnooj ecotype had the lower ionic leakage than the others. The results of this research revealed that Golbaf ecotype in drought stress and Ghale-ganj ecotype in drought by applying super absorbent conditions had significant performance. Application of super absorbent polymer increased 55.3% in grain yield compared to the non-application under drought stress. Stoker (1960) reported that drought stress leaded to increase in ionic leakage and reduced plant height and create short plants. Application of super absorbent polymers to reduce the devastating effects of drought on soybean and corn have been reported.
ConclusionThe super absorbent polymer increased grain yield compared to normal irrigation which indicating very positive and direct effect of this polymer in maintaining soil moisture nearby the plant roots and reducing the adverse effects of drought stress as well as increasing grain yield in millet ecotypes, therefore could be helpful materials for more utilization of plants potential in conditions and environments with water limitation.

To evaluate the effect of superabsorbent and without application of quantitative and qualitative characteristics of sunflower oil and water deficit stress conditions, the pilot in 1391, Azad University of Varamin Agricultural Research Station (Pishva) was carried out. This study was a split plot in a randomized complete block design with three replications. Where irrigation as main factors (lack of tension, the tension in the fourth and fifth pair of leaves, water stress at flowering, drought in the fourth and fifth pairs of leaves and flowering) and the concentration of the polymer, super absorbent (zero, 15 and 30 kg per ha) as sub plots were purpose. Traits such as seed yield, oil content, protein content, chlorophyll and relative water content were studied. The results showed that water deficit, particularly at the flowering stage reduced the grain yield, leaf chlorophyll content, leaf relative water content, oil content and the increased use of super absorbent of all the characters. Stress protein was also increased. The results obtained in this experiment can be concluded that the most critical stage in the flowering stage and twostage stress (vegetative and reproductive) is very sensitive to drought stress and Application of 30 kg ha super absorbent to lessen the impact of drought was identified as the best treatments.

To evaluate the effect of improvers and water deficit on seed yield and irrigation water use efficiency of sunflower (Helianthus annuus L.)، a field experiment was conducted as split-factorial in randomized complete block design with three replications in Isfahan and Tehran، Iran، during the 2012 growing season. Experimental treatments were 1- water stress at three levels; 60، 120 and 180 mm evaporation form class A pan were assigned to main plots، 2- soil improvers at three levels; control (no application)، zeolite (4. 5 t. ha-1) and super absorbent polymer (100 kg. ha-1) and 3- plant improvers at theree levels; control (zero)، calcium silicate (400 mg. l-1) and Hexaconazole (2 g. l-1) as factorial were randomized in sub-plots. Water deficit significantly decreased seed yield (45%) and oil yield (20%)، biological yield (22%)، seed number per plant (32%) and 1000 seed weight (29%). Application of zeolite and hexaconazole led to higher seed yield. Water deficit at 180 mm level reduced the oil yield by 58%. Application of super absorbent polymer and calcium silicate reduced the effect of water deficit stress by 19%. Application of zeolites and hexaconazole had the highest irrigation water use efficiency (IWUE). IWUE increased with application of combination of soil and plant improverby 25% to 59%.

A pot experiment was carried out as a factorial in completely randomized design with superabsorbent polymer (A200) at 0 (control), 10, 20, 30, 40 and 50 g/kg soil as the first factor and different levels of salinity including 0 (ordinary water), 3, 6, 9, 12 and 15 dS/m as the second factor and a total of 108 pots containing 2 kg soil. The pots contain 2 kg of a farm soil. Analysis of variance showed that the effect of super absorbent, salinity and these interactions on soil moisture and drainage water EC was at P<0.01. According to the results, super absorbent polymers application, when irrigation water is saline, is not recommended and mixture application of this polymer with organic fertilizers is suggested.

To evaluated the changes in yield and harvest index of Matricaria chamomilla at different irrigation regimes (irrigation after 50, 100, 150 and 200 mm evaporation from pan class A) and amounts of super absorbent polymer (0, 60, 120, 180, 240 and 300 kg/ha), a field experiment was conducted as factorial based on randomized complete block design with three replication at Urmia University in 2008. Results of ANOVA showed the significant effect of irrigation on the yield of dried flower and essential oil with 4 hours extracting standard, and significant effect of polymer on the yield of essential oil with 2 hours extracting standard as well as the significant effect of interaction between irrigation and polymer on the yield of biomass, harvest index of dried flower, harvest index of essential oil with 2 and 4 hours extracting standards. The highest yield of biomass (1216 kg/ha) was obtained from irrigation after 50 mm evaporation from pan without polymer application and the minimum one (164 kg/ha) obtained from irrigation after 200 mm evaporation and 120 kg/ha of polymer use. The maximum yield of dried flower (117 kg/ha) was obtained from irrigation after 50 mm evaporation, but prolonged interval and sever water stress in irrigation after 150 mm evaporation caused the significant reduction of yield (76 kg/ha). The highest (2.19 kg/ha) and the lowest (1.06 kg/ha) yield of essential oil with 2 hours extracting standard, were occurred at 180 and 60 kg/ha of super absorbent polymer, respectively. However, the maximum (2.06 kg/ha) and minimum (1.35 kg/ha) yield of essential oil with 4 hours extracting standard, belonged to irrigation after 50 and 150 mm evaporation from pan, respectively. The highest harvest index of dried flower and essential oil with 2 and 4 hours extracting standards (39, 0.45 and 0.77 %, respectively) belonged to irrigation after 200 mm evaporation from pan class A and 120 kg/ha of super absorbent treatment. In conclusion, increasing irrigation interval up to irrigation after 100 mm evaporation caused to reduce the yield of anise, in that super absorbent polymer application improved the yield.

Drought stress is one of the most important problems of agriculture in arid and semiarid regions of the world. The application of substances such as superabsorbent polymers in soils may decrease fertilizers leaching and increase water retention in the soil which reduces crop water use in turn. This experiment was conducted with corn (Zea mays L.) in Dashtak, Zahedan during growing season 2012. The experiment was done as a split-plot with three irrigation regimes including irrigation to provide 60%, 80% and 100% corn water requirement (ETc) as main plots and four amounts of superabsorbent polymer (SAP) including 0, 30, 60 and 90 kg ha-1 as subplots in a completely randomized block design with three replications. The results showed that the effect of irrigation regimes, SAP levels and interaction between the two factors had significant effect on all studied traits. The regression models estimated for relative water content (RWC), chlorophyll index (CI), remobilization of photosynthetic matters (RPM), portion of remobilization to seed and seed yield indicted that applying SAP under 100% ETc had no effect on above traits, while all corn traits were improved under drought stress. The results also showed that applying 60 kg ha-1 SAP decreased corn water requirement as much as 20% and caused a seed yield and physiological characters equivalent to that of the 100% ETc.

Drought stress is one of the most important factors controlling plant growth in arid and semi arid regions. Super absorbent polymers has introduced for absorbing seasonal rain to decrease moisture stress. As a result of over population and industrialization, water shortage is pronounced in dry or semi arid areas; hence use of waste water for some crops is being important. This study aimed to evaluate the multiple effects of municipal wastewater and super absorbent polymer on Nitraria schoberi growth under greenhouse conditions. In this study factorial complete randomized design with four replications was used. The treatments used included: two types of soils (clay and sandy), three level of super absorbent (0, 4, and 8), irrigation at two levels (wastewater and Tap water) and two irrigation regimes (5 and 15 days). The results indicated that the number of established seedlings, plant height and root length, plant dry weight were affected by different quantities of super absorbent and wastewater. According to results, application of polymers significantly increased water holding capacity especially in sandy soils. Therefore using polymer can increase the success chance of seedling establishment in rehabilitation projects.

In order to study the effect of super absorbent polymer on some agronomic characters(yield, seed 100 weight and Harvest index) and phyisiological characters (EC,RWC) in redbean (phaseolus vulgaris) varieties under drought stress, various tests conducted inlaboratory and greenhouse experiments in research station of the Islamic Azad University,Karaj Branch in 2005. In greenhouse experiment factorial design under randomizedcomplete block design (RCBD) with four replications were used, varieties were factor A(Derakhshan, D81083, Naz) and time of irrigation was factor B and C with superabsorbent concentration (0,%5,%7). Irrigation treatment was on main plot, and factor B,C were on sub plot. The results showed significant difference between irrigation treatments, varieties and polymers concentration for measured characteristics.Drought stress caused significant effects on increasing EC and reduced seed yield, seed 100 weight and Harvest index. super absorbent polymer (7%) increased the agronomic characteristics.Naz and Derakhshan varieties were drought tolerant and sensitive varieties respectively.The results showed that super absorbent,absorb and keep the water around the roots and it can reduce death of plants from water shortage. These compounds can increase agronomic characteristics, so with attention to increasing yield and yield components and reducing the use of water, application of superabsorbent was proposed specially in water deficit condition.