Effect Of Trace Elements On Plant Growth And Nut Yield Of Carya Cathayensis

A field survey was carried out to examine soil trace element status in Chinese hickory(Carya cathayensis) forests in major production towns of Linan city, Zhejiang province. Results showed that the availabilities of soil trace elements varied greatly with locations and among individual trace element as well. Of the surveyed forests, the soils with low available trace elements, at deficient level, possessed 1.05% for iron(Fe), 4.23% for manganese(Mn), 98.4% for boron(B), 58.2% for zinc(Zn) and 7.41% for copper(Cu). So soil B deficiency is most serious, followed by Zn deficiency, while Cu deficiency to some extent.Micronutrients may be deficient in acid soils especially this could be induced by excessive liming. A 2 year term field experiment showed that micronutrient(B, Zn and Cu) fertilizers effectively improved B and Zn concentrations in the leaves of Carya cathayensis trees, increased by in the range of 5.3% to 46.2%(B) and 2.3 44.5%(Zn) respectively, yet not for leave Cu concentration. Results also showed that the micronutrient fertilizers improved pollen vitality effectively, when treated with B and Zn together(B100Zn100Cu0), pollen vitality value reached as high as 60.68%. By contrast, it was only 44.6%,when no micronutrient was applied. Consequently, the nut yield of Carya cathayensis trees was highest by B100Zn100Cu0 treatment, especially this was more apparent in year 2.While in the common limestone soil, in which most of the Carya cathayensis) forests grow, it also showed that micronutrient(B,Zn and Cu) fertilizers effectively improved B and Zn concentrations in the leaves of Carya cathayensis trees in a 2 year term field experiment, and leaf Cu concentration was also increased. Soil analysis showed that soil available B, Zn and Cu were improved by micronutrient(B, Zn and Cu) fertilizers application. This revealed that leaf micronutrient concentrations are closely related with soil available micronutrient levels. Similarly, nut yield was improved by micronutrient fertilization treatment.In conclusion, application of micronutrient(B, Zn and Cu) fertilizers improved availabilites of soil micronutrients, especially B and Zn. This led to increase plant micronutrient concentrations in the leaves and improved plant micronutrient nutrional status and pollen viability, so that reproduction was improved and finaly nut yield was increased.