نشریه بوم شناسی گیاهان زراعی
سال نهم شماره 3 (پیاپی 32، پاییز 1392)

This study is carried out in two sites under agroforestry system (under tree canopy and between tree rows) and in a farmland without tree plantation for determination soil carbon storage in South Biarjomand region، Semnan province، Iran. Soil samples were taken through systematic-random method from two depths (0-25 and 25-50 cm) in three different places including under tree canopy، between trees and control area. Relationship between some physical and chemical properties of soil and its organic carbon content was also studied. Results showed that carbon storage (sequestration) under tree canopy
was 31 ton. ha-1 higher than that in between tree rows (42 ton. ha-1). Also، total carbon storage in between tree rows was significantly higher than that in the control (7. 4 ton. ha-1). Besides، carbon sequestration was higher in the first soil surface layer (0-25 cm) in under tree canopy and between tree rows. Stepwise regression analysis also showed that pH was the most effective factor in carbon sequestration and soil nitrogen and sand were placed in the second class with 13. 4 and 5. 6 % lmpact، respectively.

The effect of irrigation intervals، humic acid and plant growth promoting Rhizobacteria (Azotobacter، Azospirillum pseudomonas) was studied on yield and yield components of wheat (Kavir cultivar) in Fashafuyeh region، Iran in 2010-2011. Experiment was carried out as split factorial based on a randomized complete block design with four replications. Main Factor was irrigation at three levels (irrigation after 80، 120 and 160 mm evaporation from class A evaporation pan) and humid acid and plant growth promoting Rhizobacteria at two levels of application and non-application were considered as sub-factors. The result indicated that water stress significantly decreased seed yield duo to a decreased seed numbers per spike. Water stress also decreased biological yield، significantly. Application of plant growth promoting Rhizobacteria significantly effected seed yield and harvest index percentage. Besides، application of humid acid increased spike number per unit area and biological yield in high stress condition (irrigation after 160 mm evaporation from class A evaporation pan). According to the results، application of plant growth promoting Rhizobacteria and humid acid as two important biological fertilizers can reduce inverse effect of water deficit stress on yield and yield components of wheat.

In order to study the response of soil properties and sweet corn traits to different levels of organic and chemical fertilizers of nitrogen, a greenhouse-laboratory research was carried out as factorial based on a completely randomized design with three replications in Miyaneh Branch, Islamid Azad University. Experimental factors included poultry manure at three levels (0, 20 and 30 ton.ha-1) and nitrogen fertilizer at three levels (0, 100 and 200 kg.ha-1 from urea source). Results showed that application of poultry manure in soil increased soil pH, EC and organic carbon. Also, it had a significant effect on chlorophyll content, plant height and leaf area of sweet corn plants. Application of 20 and 30 ton.ha-1 poultry manure resulted in higher values of the studied traits. However, there was no significant differences between 20 and 30 ton.ha-1 poultry manure in most cases and so, application of 20 ton.ha-1 poultry manure was enough for achieving optimal sweet corn growth in greenhouse. According to the results, combined application of 20 ton.ha-1 poultry manure and 100 kg.ha-1 nitrogen from urea source could be recommended for optimum nitrogen supplying in sweet corn cropping system.

The effect of foliar application of zinc on yield and seed quality of wheat under water deficit was studied as split factorial experiment based on a randomized complete block design with three replications in 2009-2010. Main factor was water deficit condition at three levels of complete irrigation, irrigation halting after pollination, and after grain milk stage. Sub-factors were three wheat genotypes (Mahdavi, Shiraz and Pishtaz) and three different concentrations of zinc (0, 2.5 and 5 mg.kg-1). Results revealed that grain yield, total dry matter and harvest index were reduced and seed protein was increased with stress intensity increasing. All cultivars, particularly Mahdavi showed high performances at complete irrigation condition. However, Pishtaz produced higher grain yield (6107 kg) at irrigation halting after pollination. According to the results, zinc sulfate had positive significant effect on most of the studied traits and application of zinc sulfate 2.5 mg.kg-1 increased grain yield of wheat up to 27% at complete irrigation condition. Besides, zinc sulfate application increased zinc concentration in seeds, significantly.

Effect of soil and foliar application of Fe, Zn and both Fe and Zn fertilizers on growth and yield of green bean was evaluated as factorial based on a rondomized complete block design. Factors were fertilizer type (Fe, Zn, and both Fe and Zn fertilizers) and fertilizer type and application time (control, soil application of fertilizers, foliar application at vegetative stage, foliar application at early flowering stage, foliar application at two vegetative and flowering stages, foliar application after harvest, foliar application at three vegetative, early flowering and after harvest stages). Based on the results, soil application of fertilizers, foliar application at two vegetative and flowering stages and foliar application at three vegetative, early flowering and after harvest stages increased plant height, leaf number, leaf dry weight, stem dry weight, shoot dry weight and yield, significantly. Application of both Fe and Zn fertilizers was more effective than solely application of each fertilizer in leaf number, leaf dry weight, stem dry weight, shoot dry weight and yield. Maximum yield 2.29 kg/m2) was obtained by application of both fertilizers and minimum rate (1.82 kg/m2) was observed when Fe fertilizer was applied solely. Pod yield was also 65, 59 and 65% higer than the control in soil application of fertilizers, foliar application at two vegetative and flowering stages and foliar application at three vegetative, early flowering and after harvest stages treatments, respectively. Combined application of Fe and Zn and solely application of Zn resulted in a higher Zn content in plant in comparison to the solely application of Fe. Besides, the lowest Zn content in plant was obtained in foliar fertilizer application at vegetative stage. Also, combined application of Fe and Zn and solely application of Fe resulted in a higher Fe content in plant in comparison to the solely application of Zn. The minimum impact on increasing Fe concent in plant was observed in foliar application of fertilizers at early flowering stage.

To study the effect of salicylic acid on growth indices of mung bean, Vigna radiata L. (Var. NM92) under water deficit stress condition, a split-plot experiment was carried out based on a randomized complete block design with three replications in Research Station of Urmia University in 2012. The main factor was water deficit stress with three levels of irrigation at soil moisture of 75% Fc (control), 60% Fc and 50% Fc field capacity in the root zone), and foliar application of salicylic acid was considered as sub factor with four levels (0, 0.1, 0.5 and 1 mM). Results showed that application of 0.5 Mm salicylic acid caused the highest values for all the growth indices studied. Salicylic acid 0.5 Mm resulted in the highest total dry matter (TDM), leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR) and net absorbsion rate (NAR) in almost all growth stages in comparison to the other treatments and therefore, it can be concluded that foliar application of salicylic acid 0.5 mM can ameliorate the adverse effects of water deficit on growth indices of mung bean.

Possibility of reducing drought stress adverse effects on yield and osmolate content of radish (var. Radish cherry bell) by application a plant growth regulator, salicylic acid, was studied in Shiraz Branch, Islamic Azad University, Fars province, Iran in 2012. Experiment was carried out as factorial based on a completely randomized design (CRD) with three replications under a long-term drought stress condition (45 days). Radish seeds were planted in pots with sandy-clay soil and drought stress was applied after two leaf stage. Factors were drought stress at three levels of one-day (normal), three-days (mild stress) and five-days (severe stress) irrigation intervals and salicylic acid at three levels (0, 1 and 2 mM). Yeild traits including length, diameter and weight of hypocotyl (under ground eatable part) and osmolates (prolin and soluble carbohydrates) were measured. The results showed that interaction effect of drought stress and salicylic acid was significant on all the studied traits. Sever stress condition caused a considerable reduction in hypocotyl length and diameter. Foliar application of salicylic acid 2 mM caused higher osmolate rates and it reduced the adverse effect of drought stress on radish yield.

In order to study the effect of surface and local irrigation (Tape) methods on yield and water use efficiency of three common bean cultivars (Phaseolus vulgaris L.) in different planting patterns, a split split plot experiment was conducted based on a randomized complete block design with three replications in Khoramdareh region, Iran in 2011 and 2012. Khomain, Talash and COS16 cultivars were planted in sub sub plots, furrow and without furrow were placed in sub-plots and surface and local irrigation (Tape) methods were considered as levels of the main factor. Results showed that tape irrigation increased seed yield up to 28% in comparison to the surface irrigation in pinto common bean cultivation. Khomain and COS16 produced 36% and 32% more yield than Talash cultivar, respectively. It was duo to higher seed number per plant in COS16 and higher 100 seed weight of Khomain cultivar. COS16 showed a better response to local irrigation and furrow planting pattern, because it has type I (erect type) growth form. The response of cultivars to irrigation methods and planting patterns was different, so that the highest seed yield was obtained from Khomain cultivar with tape irrigation and without furrow (3329.8 kg/ha), Khomain cultivar with tape irrigation and furrow (3020 kg/ha) and COS16 cultivar with tape irrigation and furrow (3010.4 kg/ha). The highest value for water use efficiency 1.12 kg/m3) was obtained by local irrigation (Tape). In tape irrigation method, volume of used water was 32% lesser than the surface irrigation and seed yield was increased more than 28%. All cultivars produced higher yield in tape irrigation method, but they showed different responses to the planting pattern.