نقش پارامتر هاي آب هوايي بر عملكرد محصول بادام مطالعه موردي: سبزوار

The role of climatic parameters on yield of almond Case Study: Sabzevar

در حال حاضر كشاورزي يكي از مهمترين بخشهاي اقتصادي يك كشور به شمار  مي آيد. بازده توليد محصولات كشاورزي تا حدود زيادي با شرايط اقليمي در ارتباط است. بررسي اثرات شرايط اقليمي بر ميزان توليد محصولات كشاورزي مي تواند كمك موثري به انتخاب مناسب ترين گياه براي كشت محصول بنمايد. امروزه بزرگترين مسأله در هواشناسي كشاورزي، اثر عوامل آب و هوايي بر روي محصولات كشاورزي است. در اين تحقيق، براي بررسي اثر پارامترهاي آب و هوايي بر عملكرد محصول بادام در سطح شهرستان سبزوار، از پارامتر هاي هواشناسي ميانگين حداقل دما، ميانگين حداكثر دما، ميانگين دما، بارش، ساعات آفتابي، دماي تر، دماي خشك، رطوبت نسبي و سرعت باد ايستگاه همديد سبزوار در بازه­ي زماني 1390-1361 استفاده شده است. در اين تحقيق براي بررسي ارتباط بين پارامترهاي هواشناسي و عملكرد بادام از روش همبستگي پيرسون  در بازه هاي زماني مختلف استفاده شده است. نتايج نشان مي دهد  كه از بين پارامتر آب هوايي دماي بيشينه بيشترين همبستگي منفي معني دار را با توليد و عملكرد محصول بادام  داشته است. در اين تحقيق روند تغييرات آغاز مراحل فنولوژي محصول  با استفاده از آزمون ناپارامتري  من كندال و آزمون پارامتري تي تست  مورد ارزيابي قرار گرفته است. نتايج تحليل نشان مي دهد زمان آغاز مراحل فنولوژي در پاسخ به گرمايش جهاني در هر دو روش داراي روند كاهشي معني دار مي باشد.

Introduction       Climate is one of the basic elements of the environment that controls all aspects of life. Among the elements of climate, air temperature and precipitation play a crucial role. Temperature as an indicator of the severity of heat is one of the essential elements of knowledge about climate. Solar energy received by the earth is undergoing many changes in climate system. Effect of climatic factors on the performance of agricultural production is extremely important. If the knowledge on the climatic factors is not existed, much success could not be achieved. Material and methods       In this study, the mean temperature, wet bulb temperature, dry bulb temperature, relative humidity, rainfall, sunshine and wind speed is applied. We got variable values in the period between 19822011 from the city of Sabzevar weather office. Data quality control is done and wrong values of the time series of climatic elements is removed. Then, the correlation coefficient were calculated from parameters at various time intervals of a month, two months, three months, six months and a year were calculated. The date of phonological stages of almond is used from Golmakan agrometeorological station and the value of mentioned above variables are obtained in the different phonological stages. In the next step, trend analysis is applied on the time series of climatic variables. Then, factor analysis was applied on the variables that have correlation coefficient with almond yield. In the final step, the clustering analysis is used to gouping the main variables.   Results and discussion       Results show that the main factors affecting the performance of almonds can be placed in 3 separate clusters as follows: 1 The first cluster consists of dry bulb temperature in Feb March, wet bulb temperature in February May, dry bulb temperature in March, wet bulb temperature in February –March, minimum temperature in March and minimum temperature in February March. 2 The second cluster consists of Maximum temperature in December, dry bulb temperature in winter, Maximum temperature in February March, Maximum temperature in March and air temperature range in Oct. 3 The third cluster consists of Maximum temperature in April, dry bulb temperature in July and minimum temperature in July.   Conclusion       In this study, using Pearson correlation, the relation between almond crop yield and the climatic elements was evaluated. The results showed that the maximum temperature has the most significant negative correlation with performance of almonds. The results also showed that the start date of phonological stages is significant decreasing trend. In other words, the phonological stages are started earlier.