مطالعه عوامل موثر بركاهش عملكرد گياه گندم در منطقه ماهدشت كرج

Study of effective factors on reducing wheat grain yield in Mahdasht region of Karaj

ﯾﮑﯽ از ﻣﺸﮑﻼت اﺳﺎﺳﯽ ﺗﻮﻟﯿﺪ ﮔﯿﺎﻫﺎن زراﻋﯽ در ﮐﺸﻮر ﻣﺎ اﺧﺘﻼف ﺑﯿﻦ ﻋﻤﻠﮑﺮد واﻗﻌﯽ ﮐﺸﺎورزان و ﻋﻤﻠﮑﺮد ﻗﺎﺑﻞ ﺣﺼﻮل ﯾﺎ ﻫﻤﺎن ﺧﻼء ﻋﻤﻠﮑﺮد ﻣﯽ ﺑﺎﺷﺪ. ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﻋﻮاﻣﻞ ﻣﺪﯾﺮﯾﺘﯽ ﻣﻮﺛﺮ ﺑﺮ ﮐﺎﻫﺶ ﻋﻤﻠﮑﺮد داﻧﻪ ﮔﻨﺪم در ﻣﻨﻄﻘﻪ ﻣﺎﻫﺪﺷﺖ ﮐﺮج، آزﻣﺎﯾﺸﯽ ﺑﻪ ﺻﻮرت ﻣﯿﺪاﻧﯽ در ﺳﺎل زراﻋﯽ 1396-97 در ﻣﺰارع ﻣﻨﻄﻘﻪ ﻣﺎﻫﺪﺷﺖ ﺻﻮرت ﮔﺮﻓﺖ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﺑﺎ اﺳﺘﻔﺎده از رﮔﺮﺳﯿﻮن ﮔﺎم ﺑﻪ ﮔﺎم ﺳﻬﻢ ﮐﻠﯿﻪ ﻋﻮاﻣﻞ ﻣﺪﯾﺮﯾﺘﯽ ﮐﻪ ﻣﻤﮑﻦ اﺳﺖ درﮐﺎﻫﺶ ﻋﻤﻠﮑﺮد ﻧﻘﺶ داﺷﺘﻪ ﺑﺎﺷﺪ ﺗﻌﯿﯿﻦ ﮔﺮدﯾﺪ. ﻧﺘﺎﯾﺞ ﻫﻤﺒﺴﺘﮕﯽ ﺑﯿﻦ ﻋﻮاﻣﻞ ﻣﺨﺘﻠﻒ ﻧﺸﺎن داد ﻋﻤﻠﮑﺮد داﻧﻪ ﺑﺎ ﻣﻘﺎدﯾﺮ ﺗﻌﺪاد دﻓﻌﺎت آﺑﯿﺎري، ﻣﺼﺮف ﻧﯿﺘﺮوژن در ﻣﺮﺣﻠﻪ دوم، ﮐﻞ ﻧﯿﺘﺮوژن ﻣﺼﺮﻓﯽ در ﻃﻮل دوره رﺷﺪ و ﻣﺼﺮف رﯾﺰ ﻣﻐﺰي ﻫﻤﺒﺴﺘﮕﯽ ﻣﺜﺒﺖ و ﻣﻌﻨﯽ داري در ﺳﻄﺢ اﺣﺘﻤﺎل 1 درﺻﺪ و ﺑﺎ ﺳﻄﺢ زﯾﺮ ﮐﺸﺖ ﻫﻤﺒﺴﺘﮕﯽ ﻣﺜﺒﺖ و ﻣﻌﻨﯽ داري در ﺳﻄﺢ اﺣﺘﻤﺎل 5 درﺻﺪ دارد. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻣﻘﺎدﯾﺮ ﻋﻤﻠﮑﺮد ﮔﻨﺪم ﺛﺒﺖ ﺷﺪه، ﻣﯿﺎﻧﮕﯿﻦ ﻋﻤﻠﮑﺮد واﻗﻌﯽ داﻧﻪ ﮔﻨﺪم 4775 ﮐﯿﻠﻮﮔﺮم در ﻫﮑﺘﺎر ﺑﻪ دﺳﺖ آﻣﺪ و ﻋﻮاﻣﻞ ﻣﻮﺛﺮ ﺑﺮ ﮐﺎﻫﺶ ﻋﻤﻠﮑﺮد در اﯾﻦ ﻣﻨﻄﻘﻪ ﺷﺎﻣﻞ ﺗﻌﺪاد دﻓﻌﺎت آﺑﯿﺎري )42 درﺻﺪ(، ﺳﻄﺢ زﯾﺮ ﮐﺸﺖ )9 درﺻﺪ(، ﻣﺤﺼﻮل ﻗﺒﻠﯽ ﮐﺸﺖ ﺷﺪه )6 درﺻﺪ( و ﮐﻞ ﻧﯿﺘﺮوژن ﻣﺼﺮﻓﯽ )5 درﺻﺪ( ﺗﻌﯿﯿﻦ ﮔﺮدﯾﺪ. دﯾﮕﺮ ﻋﻮاﻣﻞ ﻣﺪﯾﺮﯾﺘﯽ ﺗﺄﺛﯿﺮ ﻧﺎﭼﯿﺰي در ﮐﺎﻫﺶ ﻋﻤﻠﮑﺮد از ﺧﻮد ﻧﺸﺎن دادﻧﺪ. ﻋﻤﻠﮑﺮد داﻧﻪ ﭘﺘﺎﻧﺴﯿﻞ در ﻣﻨﻄﻘﻪ ﻣﺎﻫﺪﺷﺖ ﮐﺮج ﻃﺒﻖ ﻣﺪل رﮔﺮﺳﯿﻮﻧﯽ ﺗﺎ 7630 ﮐﯿﻠﻮﮔﺮم ﺑﺮ ﻫﮑﺘﺎر ﻗﺎﺑﻞ ارﺗﻘﺎء ﻣﯽ ﺑﺎﺷﺪ ﮐﻪ ﺧﻼء ﻋﻤﻠﮑﺮد در اﯾﻦ ﻣﻨﻄﻘﻪ ﺣﺪود 2860 ﮐﯿﻠﻮﮔﺮم ﺑﺮ ﻫﮑﺘﺎر ﺑﻪ دﺳﺖ ﻣﯽ آﯾﺪ.

One of the main problems of crop production in our country is the difference between the actual grain yield of farmers and the achievable grain yield or the yield gap. In order to investigate the management factors affecting the reduction of wheat yield in Mahdasht of Karaj, a field experiment was conducted in the crop year 2017-18 in the farms of Mahdasht which was previously selected by the researcher. In this study, using stepwise regression, the contribution of all management factors that may play a role in reducing yield has been investigated. The results of correlation between different factors showed a positive and significant correlation between grain yield with the number of irrigations, nitrogen application in the second stage, total nitrogen consumption during the growing period and micronutrient consumption at a probability level of 1%, and there was a positive and significant correlation with the area under cultivation at the 5% probability level. According to the recorded wheat grain yield values, the average actual wheat grain yield was 4775 kg.ha-1 and factors affecting yield reduction in this area including the number of irrigations (42%), area under cultivation (9%), previously cultivated crop (6%) and total nitrogen consumption (5%) were determined. Other management factors had little effect on grain yield reduction. Potential grain yield in Mahdasht of Karaj according to the regression model can be raised to 7630 kg.ha-1, and the grain yield gap in this area is 2860 kg.ha-1.