核桃树体生物量构成及矿质营养元素累积特性研究

Compositional analysis of biomass and accumulation properties of mineral elements in Walnut

为了给核桃合理施肥提供科学依据,以5 a生温185早实核桃树为试材,采用彻底刨根、分解取样的方法,研究了生物量的构成特点、各器官矿质元素含量和累积分配特性。结果表明,核桃树总干质量为32 814 g.plant-1,其中当年新生营养器官占16.36%,果实占13.59%,老营养器官占70.05%。N含量以种仁最高,叶片次之;P含量以叶柄最高,青皮次之;K含量以青皮最高,叶片、叶柄次之。核桃树N、P、K、Ca、Mg总累积量为366.67、48.92、247.37、440.19和62.32 g.plant-1,其中,N主要分配到种仁、叶片、多年生枝和主根,P主要分配到主根、种仁、多年生枝、叶片和青皮,K主要分配到青皮和叶片。每生产1 000 kg干商品核桃需吸收N 77.05 kg、P 9.70 kg、K 62.24 kg、Ca 75.41 kg、Mg13.35 kg。核桃树对N、K、Ca的需求较多,对P、Mg的需求较少;营养器官累积N、Ca较多,累积P、K、Mg较少;生殖器官累积N、K较多,累积P、Ca、Mg较少。

The aim of this study was to investigate the properties of accumulation and distribution of min- eral elements in Walnut （Juglans regia L. ） and to establish a reasonable fertilization protocol. Field exper- iments were conducted to analyze the character of biomass composition, mineral element content and its accumulation in different parts of Walnut trees which were about 5 years old. The total dry biomass of wal- nut was 32814 g .plant-＇ in which new vegetative organs of the year accounted for 16.36%, fruits for 13.59% and old vegetative organs for 70.05%, respectively. The nitrogen （N） content was the highest in the kernel （36.4 g· kg^-1）, 30.2 g· kg^-1 in the leaf and the lowest in the shell （2.4 g·kg^-1）. The phosphorus （P） content was the highest in the petiole （7.2 g·kg^-1） , 3.7 g ·kg^-1 in the shuck and lowest in the shell （0.17 g. kg^-1）. The potassium （K） content was the highest in the shuck （75.3 g· kg^-1）, 15.4 g-kg-lin the leaf, 15.4 g·kg^-1 in the petiole and 11.0 g.kg^-1 in the new branch. The calcium （Ca） content was the highest in the Petiole （44.9 g·kg^-1）, 29.9 g·kg^-1 in the leaf and the lowest in the kernel （0.62 g.kg-1）. The magnesium （Mg） content was the highest in the petiole （6.4 g·kg^-1）, 6.2 g-kg^-1 in the leaf and 5.1 g·kg^-1 in the shuck. Total N, P, K, Ca and Mg amount in Walnut tree were 366.67, 48.92, 247.37, 440.19 and 62.32 g .plant^-1, respectively. Nitrogen was mainly distributed in the kernel, leaf, limb and taproot. Phosphorus was mainly distributed in the taproot, kernel, limb, leaf and shuck. Potassium was mainly distributed in the shuck and leaf. Calcium was mainly distributed in the leaf, limb, 3 years branch, 2 years branch and trunk. Magnesium was mainly distributed in the leaf, taproot, shuck and Limb. To obtain 1 000 kg dry matter of fruits, Walnut trees must uptake N 77.05 kg, P 9.70 kg, K 62.24 kg, Ca 75.41 kg and Mg 13.35 kg. Walnut tree absorbed more N, K, Ca than P, Mg. The vegetative organs accumulated more N, Ca than P, K, Mg. The reproductive organs accumulated more N, K than P, Ca, Mg.