薄壳山核桃树体生物量构成及养分需求规律

Biomass composition and fertilizer requirement in Carya illinoensis

【目的】探明薄壳山核桃幼林植株生物量构成及养分需求规律,为薄壳山核桃幼株合理施肥提供理论依据。【方法】通过开展薄壳山核桃幼株生物量构成调查和矿质元素含量测定,明确不同生长发育期幼株养分需求情况,采用彻底刨根分解取样法测定不同生长发育期幼株不同器官的生物量以及N、P、K、Ca、Mg、Fe、Mn、Cu和Zn等矿质养分含量,计算幼株年周期内矿质养分需求比例。【结果】薄壳山核桃幼株生物量主要由根、茎、枝和叶构成,根生物量约占全株的1/2,枝生物量约占1/3,茎生物量约占1/7,叶生物量约占1/25,不同时期幼株干物质含量从高到低依次为11月、3月、9月、7月、5月,不同器官相对干物质含量从高到低依次为地下部分、根、地上部分、枝、茎、叶;幼株单株当年生物量中大量元素N、P、K、Ca、Mg分配比例为8.02︰1.00︰9.24︰31.15︰1.09,Ca的占比最大,达60.71%,微量元素Mn、Fe、Cu、Zn的分配比例为43.06︰28.31︰1.00︰4.96,薄壳山核桃幼株对Mn和Fe的需求远大于其他微量元素,在3月主要需求Fe,5月主要需求N、P和Mg,7月主要需求Mg和Fe,9月主要需求K,11月主要需求Ca,Mn在5—11月需求都较大。【结论】明确了薄壳山核桃幼株不同器官生物量的构成比例,大量元素和微量元素的需求配比,以及不同生长发育期对不同矿质养分的需求状况。

【Objective】To explore the biomass composition and nutrient demand rules of Carya illinoensis young plants,which could provide a theoretical basis for the rational fertilization of young plants.【Method】Through the investigation of the biomass composition of young plants and the determination of mineral element content,the nutrient demand of young plants in different growth and development periods was clarified.The biomass of different organs,including the content of N,P,K,Ca,Mg,Fe,Mn,Cu and Zn,was used to calculate the proportion of mineral nutrient demand in the annual cycle of young plants.【Result】The biomass of young plants was mainly composed of roots,stems,branches and leaves,root biomass was about 1/2 of the whole plant,The branch biomass was about 1/3,stem biomass accounts for about 1/7,leaf biomass was about 1/25.The dry matter contents in different periods in a decreasing order was November,March,September,July,May,and the relative dry matter contents in different organs in a decreasing order was underground,root,above ground,branch,stem,leaf;The allocation ratio of major elements of N,P,K,Ca,Mg in the biomass of each single plant was 8.02:1.00:9.24:31.15:1.09,in which,the ratio contents of Ca was the highest,which was up to 60.71%;The distribution ratio of micro elements of Mn,Fe,Cu and Zn was 43.06:28.31:1.00:4.96,and the demand for Mn and Fe was much greater than that of other micro elements;The primary demand for young plants in March was Fe,and in May was N,P and Mg,and in July was Mg and Fe,and in September was mainly K,and in November was mainly Ca,and Mn was in high demand in both May and November.【Conclusion】The proportion of the biomass composition of different organs,the demand ratio of a large number of elements and trace elements,and the demand status of different mineral nutrients in different growth and development periods were clarified.