Soil nutrients in Torreya grandis `Merrillii' plantation

Key words: 
• pedology /
• Torreya grandis `Merrillii ' /
• soil forming source rocks /
• agrotype /
• soil fertility /
• fertilization

Abstract: The results of the study of the soil nutrients in Torreya grandis `Merrillii' plantation were as follows : (1)The average contents of total nitrogen , total phosphorus , total potassium and hydrolysable nitrogen in the 19 soilsamples of Torreya grandis `Merrillii' plantations were higher than those in ordinary hilly red-yellow soil .But the contents differed greatly among the samples :the ranges of organic matter , total nitrogen , total phosphorus , total potassium, hydrolysable nitrogen contents varied between 4.90 -29.70 , 0.83 -3.25 , 0.37 -3.34 , 1.60 -13.88 gkg-1 , and 105.00 -490.00 mgkg-1respectively .The contents of nitrogen , phosphorus and potassium in the soil samples were unproportionate :the nitrogen was excessive whereas the available potassium was scarce . (2)According to the Nutrient Grade Standard of Southern Plantation , of the 19 samples , 14 were rich or extremely rich in total and hydrolysable nitrogen , and none of them were scarce in total and hydrolysable nitrogen .8 samples were high in total phosphorus contents , 7 medium and 4 low .2 samples were high in total potassium contents , 9 medium and 8 low .Only 2 samples were low in available phosphorus contents , while 17 samples were with available potassium contents below the medium level .(3)The results were similar when samples were graded by Nutrient Grade of Green Food Plantation .But the organic matter contents were all below medium level.These indicated that due to fine management and heavy fertilization , the nitrogen , phosphorus and potassium contents were increased but unproportionate .So , more attention should be paid to the balanced fertilization , i .e ., limiting the application of nitrogen , keeping phosphorus and increasing potassium .[ Ch , 4 tab .10 ref .]