Nutritional Survey of Apple orchards of Khodabande, Zanjan Province

Apple is one of the most important temperate fruits of Iran and Zanjan province. Optimum nutrition of present orchards is essential for increasing qualitative and quantitative of yield and evaluating nutritional status of orchards and implementing correct fertilizer program have the main rule in this subject. The best way to evaluate nutritional status of a orchard in addition to assessing yield and fruit quality is the integrated soil and plant analysis. Therefore a study had done in the khodabande's apple gardens. 186 leaf samples collected in august of 2011 and 2012 from middle of current season shoots. Chemical analysis had done on the collected samples to determine concentration of N, P, K, Mn, Cu, Zn and B. In order to determine of Apple orchars nutritional requirenments was used from Deviation from Optimum Percentage (DOP) method .Using analytical data and performing interpolation between points, distribution maps of every nutrient had prepared with the Inverse Distance Weighting method. At the moment of leaf sampling, soil samples were collected from both 30 and 60 cm depth of soils and the samples transferred to laboratory for doing routine analysis. Geographical position of each samples were written using a portable GPS. With these data distribution maps of soil properties had prepared. Results showed that almost all of orchards soils had no salinity problems. Soils of orchards had pH range between 7/75 to 8. Higher lime contents and deficiency of organic matter exist in the soils. available Soil phosphorus were lower than 15 mg/Kg. available Soil Potassium of surface soils were in the optimum range but 35 percent of deeper soils had lower than 240 mg/Kg. Sever deficit of Iron and optimum amount of Mn was detected in soils data. 75 percent of surface soils and 81 percent of deeper soils had lower than 1 mg/Kg Cu so they had severe deficit of this nutrients. Deeper soils had deficiency of Zinc. In 52 percent of surface soils and 90 percent of deeper soils the amount of Boron was lower than 1 mg/Kg so there is B deficiency in soils. Amount of clay is more in the deeper soils and usually deeper soils had heavy textures. Leaf analysis showed widely deficiency was about Zinc so its deficiency observed in 98 percent of apple orchards, then Potassium with 75 percent, Phosphorus with 52 percent, Copper with 41 percent and Nitrogen with 14 percent were in the next priority orders. Excess of Mn and B with 95 percent, N with 84 percent, Cu with 59 percent and P with 48 percent and K with 25 percent spread is in the priority orders of consideration. Symptoms on leaves also showed that there is a severe deficiency of iron in the apple orchards. According to the results, it is suggested that organic substances, sulfure, potassium, zinc and Fe in Apple orchard nutrition management program is included. Keywords: Nutritional status, Deviation from Optimum Percentage, Khodabande, Apple orchards