上海‘翠冠’梨园土壤和叶片养分状况调查分析

摘要

为了摸清上海‘翠冠’梨园土壤养分状况,为合理施肥提供理论依据,对上海地区从北到南5个有代表性的‘翠冠’梨园土壤养分状况及叶片矿质营养状况进行了调查,结合相关土壤、叶片养分适宜值,分析了‘翠冠’梨园土壤、叶片养分存在的问题.结果表明:上海梨园土壤的有机质含量都在适宜标准上限左右,枫泾、仓桥的土壤有机质含量丰富,近3％.梨园土壤碱解氮、有效磷和速效钾含量在适宜标准内.徐泾、仓桥梨园的土壤呈中性,枫泾的偏酸性,pH均值分别为7.16、7.05和6.72,庄行的偏碱性,庙镇的呈碱性,pH均值分别为7.46和8.04,显著高于标准上限值7.0.土壤呈碱性,其碱解氮和速效钾含量较低,利用率低,当土壤pH回落,土壤碱解氮和速效钾含量增加,利用率高.庙镇和枫泾‘翠冠’梨叶片N含量波动大,N肥施用不合理,徐泾则叶片N含量施用均衡,仓桥、庄行施N肥较多.叶片P含量整个生长期都有超标的发生,有的高出标准上限值约50％.叶片K含量多为7 g/kg上下,明显低于标准的下限值13 g/kg.综上所述,上海‘翠冠’梨园土壤以中性或偏酸性为佳,尽管土壤有机质和主要营养物质含量适宜;但是梨树叶片中N含量不稳,P含量过多,而K含量严重缺乏;因此生产上应合理施用N肥,控制P肥,多增施K肥.%The soil nutrient conditions of pear orchards is important for pear growth.In order to provide the theoretical basis for reasonable fertilization,the soil nutrient conditions of'Cuiguan'(Pyrus pyrifolia Nakai) pear orchards in Shanghai as well as the leaf nutrient were investigated.Soil and pear leaves from five typical 'Cuiguan'pear orchards in Shanghai from north to south were used to test.Then,the soil and leaves nutrient statuses were analyzed according to the optimum standards.The results showed that soil organic matters in these pear orchards were approximately standard max,and soil organic matter content in Fengjing and Cangqiao orchards were rich to 3％.The concentrations of available N,available P and available K in soil were within the proper standard.The average pH of soil in Xujing,Cangqiao and Fengjing orchards were 7.16,7.05 and 6.72,respectively,which were 7.46 and 8.04 in Zhuanghang and Miaozhen soil,respectively,higher than standard max 7.0.The contents of available N and available K were low in the soil with the pH higher than 7.0,otherwise,which were high.The total N contents in pear leaves of Miaozhen and Fengjing orchards were higher than the upper limit standard,sometimes below the lower limit.Those in pear leaves of Xujing orchard were just right,however,which were more in Cangqiao and Zhuanghang.Total P contents in leaves of all orchards exceeded the standard limit throughout the growth,some of them were higher than the upper limit standard about 50％.The contents of total K in leaves were about 7 g/kg,which is significantly less than the standard lower limit 13 g/kg.Therefore,The soil of'Cuiguan'pear orchards in Shanghai was neutral or meta-acid and contained the proper organic matter and suitable main nutrients.However,pear leaves in all orchards were unstable in N,rich in P but lack K.So,N fertilizer should be applicated reasonably,the usage of P fertilizer needs to be limited whereas the application of K fertilize should be increased in the production.