半湿润易旱区红富士苹果园初夏土壤理化特性及施肥研究

Study on soil physical and chemical characteristics and fertilizer application at early summer in Fuji apple orchard in semi-humid and liable-drought region

通过田间调查及对高产果园（≥22 500 kg/hm2）和低产果园（〈18 000 kg/hm2）土壤样品的分析,研究了半湿润易旱区红富士果园初夏土壤理化特性。试验结果表明：高产园和低产园的物理特性和养分状况差异显著。高产园土壤pH显著低于低产园,而电导率及有机质、速效氮、速效磷、速效钾和微量元素都显著高于低产园,其养分含量均处于中等到丰富水平,符合高产优质果园土壤养分含量的标准,而低产园养分含量处于中等或缺乏水平;两类果园0-20 cm土层的养分含量均高于其它土层。有机质与速效氮、速效磷、速效钾之间均呈现显著或极显著的相关关系。根据苹果的需肥特性和土壤养分状况及有效性,初步提出了低产园的优化施肥结构模式：增施有机肥和补施氮、磷肥为主,配施一定量的钾肥和微肥,以保证苹果的丰产优质。

By the field investigation and soil chemical analysis, a study on physical and nutrient characteristics of soil was carried out in high-yield （≥22 500 kg/hm^2）and low-yield （〈 18 000 kg/hm^2） typical Fuji apple （Malus pumila ） orchard in semi-humid and liable-drought region. Results showed that a significant difference was obtained for soil physical and nutrient characteristics between high-yield and low-yield orchards. Soil pH in high-yield orchard was markedly lower than that in low-yield orchard while soil conductance and the contents of soil organic matter, available nitrogen, available phosphorus, available potassium and microelements in highyield orchard were significantly higher compared with low-yield orchard. These nutrients contents were in middle and rich level, which were accorded with standard of them in high-yield and good-quality apple orchard, but the nutrients contents in low-yield orchard were in middle or inadequate level. In addition, the nutrients contents in 0-20 cm soil layer in both of two typical orchards were higher than other layers. Furthermore, the significant or markedly significant correlations were found among organic matter, available nitrogen, available phosphorus and available potassium. On the basis of the nutrients requirement characteristics of apple tree and soil nutrients condition and their availability, we put forward preliminarily the fertilization projects to improve the yield and quality of apple in this area, which included optimizing the structure of fertilization for low-yield orchard, increasing supply of organic, nitrogen and phosphorus fertilizer and supplemental supply of potassium fertilizers and micrcelements fertilizers.