Growing Media And N?P?K Fertilization Formula For Container Seedlings Of Mytilaria Laosensis

Mytilaria laosensis is a kind of evergreen valuable native broad-leaved plants in the southern subtropical region of China,and is also an excellent great fast-growing timber tree species.With the increasing promotion and application of M.laosensis in production,it is particularly important to strengthen its quality control and cultivate high-quality seedlings.During the process of seedlings cultivation,seedling-raising media is a critical factor determining seedlings quality.Meanwhile,rational fertilization can effectively improve seedlings growth and increase its yield and quality.In order to screen out the optimal media formula and fertilizer combination for M.laosensis container seedlings,we took yellow soil and light media as ingredients;on the one hand,to study the effect of different media proportion on the growth of the seedlings with the addition of light media proportion.On the other hand,by using L16?45?orthogonal experimental design,the effect of nitrogen,phosphate and potash fertilizer on the growth of the seedlings were investigated.These can provide theoretical foundation for cultivating high-quality seedlings of M.laosensis.The main conclusions were as follows:?1?The seedling height,root diameter and total biomass tended to increase at first and then decrease with the addition of light media proportion,with the peak value at T₅?yellow soil: light media = 5: 5?,which were 3.60,1.97 and 13.5 times more than those of control?100% yellow soil?,respectively.Excepting the length of primary root,the root indicators of all treatments were larger than control.With the increasing of light substrate proportion,the total length,surface area and volume of seedlings root in all treatments showed the trend of increase at first and decrease later,and the peak appeared at T₅.The average diameter of seedling root generally showed an increasing trend with the increasing of light media proportion.The initial fluorescence?F₀?of T₅ was the least,and the maximum fluorescence?F_m?and maximum light conversion efficiency?F_v /F_m?of T₅ were the largest,so it had highest photochemical capacity.Reasonable matrix formulation can effectively increase nutrient content of M.laosensis seedlings.With the addition of light media proportion,the entire plant N?K content of the seedlings tended to increase at first and then decrease,and the entire plant P content incresed gradually and then decreased slightly or tended to stability.The entire plant N?P content reached to the maximum value at T₆,while T₅ had the highest entire plant K content.Therefore,M.laosensis container seedlings showed the best growth in media of T₅?yellow soil: light media = 5: 5?.The results of fuzzy function method showed that comprehensive evaluation of T₅ was ranked first,and had the highest seedling quality,followed by T₆?yellow soil: light media = 4: 6?.So we suggest to adopt the mixture media containing 50-60 % of light media as the growth media for M.laosensis container seedlings.?2?Different fertilizer combinations had significant effects on height,ground diameter,total biomass,chlorophyll content of M.laosensis container seedling,and all growth indices were superior to the control,which indicated fertilization formula had a promoting effect on the growth of M.laosensis container seedlings.The order of effect of 3 fertilizers on height growth of M.laosensis container seedling was N>P>K,and the optimal fertilizer combination was N₁P₃K₂?N of 50 mg per plant,P of 50 mg per plant and K of 60 mg per plant?.The orders of effects of 3 fertilizers on ground diameter growth and biomass accumulation of M.laosensis container seedling were N>K>P,and the best combinations were N₁P₄K₂?N of 50 mg per plant,P of 60 mg per plant and K of 60 mg per plant?and N₁P₄K₁?N of 50 mg per plant,P of 60 mg per plant and K of 45 mg per plant?,respectively.Leaf chlorophyll content of M.laosensis container seedlings under all NPK fertilizer combination treatments all was higher than the control.The treatment of 14?N of 200 mg per plant,P of 50 mg per plant and K of 75 mg per plant?had the highest chlorophyll content?38.67 ?g/cm²?,that was 1.83 times more than that of control?21.13 ?g/cm²?.Meanwhile,formula fertilization effectively enhanced N?P?K content of all organs of M.laosensis seedlings.By the calculation of quality indices of seedlings,the optimal fertilizer formula for M.laosensis seedlings growth was N₁P₄K₁?N of 50 mg per plant,P of 60 mg per plant and K of 45 mg per plant?.