Substrate Proportion For Growth And Nutrient Absorption In Container Seedlings Of Three Precious Tree Species

Machilus thunbergii,Machilus pauho and Cinnamomum chekiangense are important and precious tree species,Popularizing rare tree species afforestation in Zhejiang Province.Cultivation of high-quality container seedling was the key to successful afforestation,substrate composition directly determines the quality of seedlings.In this paper,one-year-old seedlings of M.thunbergii,M.pauho and C.chekiangense by pot culture,the effects of five substrates（yellow soil,sawdust and peat）on plant height,ground diameter,biomass growth and N,P,K accumulation were studied.The purpose of this study was to select the suitable substrate ratio for the cultivation of container seedlings of three precious tree species,and to provide the basis for the cultivation of high quality container seedlings.The results showed that:（1）The growth of container seedling height of three precious tree species was significantly affected by different substrate ratio.The A2（yellow soil:peat:sawdust=60:20:20）was the best substrate for plant height of M.thunbergii and M.pauho.The plant height of M.thunbergii seedlings was 22.7～23.5%higher than that of A1（yellow soil:peat:sawdust=80:10:10）and A5（100%yellow soil）,the height of M.pauho seedlings was significantly higher than that of A5 by 30.1%.The height and diameter of seedlings of C.chekiangense were significantly increased by 20.9%and 24.9%respectively in A3（yellow soil:peat:sawdust=40:30:30）,which was higher than A5（P<0.05）.（2）The leaves,branches,roots and total biomass of M.thunbergii were the largest with A2substrate,which were 24.23,25.36,36.05,85.64 g·plant^-1,respectively;The most conducive to the growth of the M.pauho is the A2 substrate,whose leaves,branches,roots and total biomass were 22.73,34.72,39.82,and 97.27 g·plant^-1,respectively;The leaves,branches,roots and total biomass of C.chekiangense cultivated on A3 substrate were 33.63,39.57,48.43,and 121.64 g·plant^-1,respectively,which were significantly higher than other treatments（P<0.05）.（3）The accumulation of nitrogen,phosphorus,and potassium of M.thunbergii was the most in the A2 substrate,and the accumulation of the whole plant is 2029.0,132.8,and 495.6 mg·plant^-1respectively;while the accumulation of nitrogen and potassium in the whole plant of M.pauho was better in the A2 substrate,respectively 1999.0,825.9 mg·plant^-1,and the A3 substrate as the largest phosphorus accumulation,with a value of 123.3 mg·plant^-1.The accumulation of nitrogen,phosphorus,and potassium of C.chekiangense plants cultivated on A3 substrate was the highest,which were 3168.8,137.3,and 673.1 mg·plant^-1,respectively.（4）Gray correlation method evaluation shows that A2（yellow soil:peat:sawdust=60:20:20）substrate was the best substrate for the growth of M.thunbergii and M.pauho container seedlings,and A3（yellow soil:peat:sawdust=40:30:30）substrate was better.