Effects Of Fertilization On Growth And Physiological Characteristics Of Ginkgo Biloba

Ginkgo biloba.L is ecological economic tree specie which is valuable for food, health care, medicine, timber, landscape, ecological protection and scientific research. Ginkgo material is excellet; wood can be used for the production of high-grade craft, carvings, furnitures, toys and interior decoration materials. As a timber forest cultivation has become one of the main directions of the cultivation of Ginkgo resources. This study was based on the study of Ginkgo timber forest in Huanghai Forest Park of Jiangsu. To provide a theoretical basis for fertilization of Ginkgo timber forests, Ginkgo height and DBH, nitrogen, phosphorus, and potassium content in Ginkgo leaves, photo-biological characteristics of new Ginkgo shoots, chlorophyll content were studied, and analyzed the relationship between physiological index and growth index. An experiment with different fertilizer treatments was designed based on single factor designs and orthogonal designs. The main conclusions were as followed:1. Whether it was single N, P, K fertilizer or combined N, P, K fertilizer, it always had great influences on Ginkgo height, DBH and new shoot length.Especially N had the greatest influence on these indicators. Maximum dosage had greatest influences on the growth indicators when it was single N, P, K fertilizer(N=600g·strain^-1 or P=800g·strain^-1 or K=200g·strain^-1). When it was combined N, P, K fertilizer, the best model for DBH growth was(g·strain^-1): N=400, P=400, K=15. The best model for Ginkgo height growth was(g·strain^-1): N=400, P=200, K=90. The best model for new shoots length growth and volume was(g·strain^-1): N=400, P=400, K=45.2. Single N, P, K fertilizer all had great influence on the chlorophyll contents in Ginkgo leaf, and single N, K fertilizer had significant effects on increasing the chlorophyll content. The influence of combined N, P and K fertilizer on chlorophyll content of Gingko was in the following order: N>K>P. The best model for chlorophyll a content increasing was(g·strain^-1): N=400, P=400, K=90. The best model for chlorophyll b and total chlorophyll content increasing was(g·strain^-1): N=400, P=600, K=90.3. Single N, P fertilizer had main effect on the GS and Pn in Ginkgo leaves, while single K fertilizer only affects the Pn. The influence of combined N, P and K fertilizer on photosynthesis indictors of Gingko was in the following order: N>P>K. The formula had most significant influence on the Ci, GS, Pn was N 400 g·strain^-1, P 400g·strain^-1 and K 90 g·strain^-1. 4. When it was single N, P, K fertilizer, single N fertilizer had better promotion effect on the N and P content of Ginkgo leaves, single P fertilizer had better promotion effect on P content in the leaves while had an inhibiting effect on the absorption of K. Single K fertilizer had better promotion effect on the N and K content in Ginkgo leaves. When it was combined N, P, K fertilizer, the best model for N content increasing was(g·strain^-1): N=400, P=200, K=90. The best model for P content increasing was(g·strain^-1): N=200, P=600, K=15. The best model for K content increasing was(g·strain^-1): N=400, P=200, K=90.With a summary of the above, Ginkgo timber forests have greatest demand of N in Huanghai forest. So the growth and physiological effects of Ginkgo were optimized by adding more N fertilizer and applying appropriate amount of P and K fertilizer in the actual production.