Effect of zeolite and potassium on some of characteristic and yield of chickpea (Cicer arietinum L.) in the different irrigation management

Chickpea (Cicer arietinum L.) is grown predominantly in Mediterranean environment where yield is faced with abiotic stresses such as water deficit. Due to shortage of water resources and sequential cropping in many areas, it is necessary to manage the irrigation water, because this would cause inadequate irrigation. Therefore, in order to achieve the maximum yield and efficient use of available water, prevention of waste of water is necessary. One of the reasons for the use of zeolite in agricultural production and productivity of soil, is the moisture absorption and maintain the property for a long time and prevent environmental pollution. Zeolite acts as a slow release fertilizer, giving the plant access to water and nutrients for more times. Also zeolite caused significant saving in water use and reducing the amount of fertilizer. Thus helping to decrease the amount of water used per crop and the contamination of aquifers due to overuse of chemical fertilizers. Adjustment of drought negative effects by maintaining inflammation pressure, transpiration reduction and increase of water use efficiency has been through consumption of potassium. Although potassium unlike N and P, does not enter into the composition of any product. Potassium has an important role either direct or indirect, under different environments, in major plant processes such as photosynthesis, respiration, protein synthesis, enzyme activation, water uptake, osmoregulation, growth and yield of plant. Considering the importance of chickpea in nutrition of human and weather conditions of arid and semiarid, supplementary irrigation is necessity for cultivation of this plant in Iran; with regard to role of zeolite and potassium in reducing sensitivity of plants to water deficit and since there is limited published work about the effect of application of potassium sulphate combined with zeolite, this research was conducted to compare their effects on some of characteristics and yield of chickpea.   Materials & Methods In order to study the effect of different irrigation regimes and different Zeolite and Potassium application on quality characteristics and yield of chickpea cv Azad, an experiment was conducted as split factorial arrangement in a randomized complete block design with three replications in Research Station of Agriculture and Natural Resource Research center of Hamadan, during 2015 cropping season. Main plot included supplementary irrigation (check as non-irrigation, supplementary irrigation at flowering, irrigations at both flowering and pod setting and irrigation at pod setting stages) and subplot included three levels of zeolite (Z0=0, Z1=15 and Z2=30 ton ha-1) and three levels of potassium fertilizer (K0=0, K1=150 and K2= 250 kg ha-1 K2SO4) that located as split factorial in each sub plot. In this study, the amount of proline, potassium, protein, chlorophyll content (flowering and pod setting stage), seed yield and Plant weight were determined. Software SAS Ver. 9.1 was used for the statistical analysis and the means were compared by using Least Significant Difference (LSD) test at 0.05 level of significance.    Results & Discussion The results showed that the different irrigation regimes, Zeolite and Potassium fertilizer levels had significant effect on proline, potassium, protein, chlorophyll (flowering stage), chlorophyll (pod setting stage) and seed yield. The results indicated that drought stress significantly decreased leaf potassium and leaf chlorophyll whereas protein percent and proline were increased. Interaction between irrigation and Zeolite was significant except for chlorophyll (pod setting). In this study, the highest plant weight and seed yield were obtained under irrigations at both flowering and pod setting along with 30 ton ha-1 zeolite. Enhanced proline accumulation during stress indicates that proline is thought to play a cardinal role as an osmoregulatory solute in plants. The flowering stage in chickpea cultivars is the most sensitive stage to drought stress and in deficit water condition supplemental irrigation in this stage may considerably increases yield of chickpea.   Conclusion Production in dry land farming systems in Iran is limited by deficiency of water. Chickpea has good potential to increase production in dry land conditions. Zeolite and potassium consumption can be positive effects on yield and quality characteristic of chickpea in severity and moderately stress conditions. It is concluded that zeolite and potassium consumption with ameliorate damages due to water stress could be effective on plant and formation economical yield in conditions of Hamadan region. Zeolite application in lands which are exposure to late season drought stress can keep soil water content and improve seed yield and production. Therefore, considering water shortage in drought area of the country, application of zeolite can be useful to save more water that leads to produce more yield. According to results of this study, potassium sulfate consumption has been enhanced 8 to 13 percent grain yield.