摘要:
根据香榧Torreya grandis `Merrillii' 林地土壤养分调查分析得出:①19 个香榧林地土壤样品的全氮、全磷、全钾和水解氮的平均值均超过一般山地红黄壤水平;土样之间差异很大, 其变异幅度分别为有机质4.90 ～ 29.7 gkg-1 , 全氮0.83 ～ 3.25 gkg-1 , 全磷0.37 ～ 3.34gkg-1 , 全钾1.60 ～ 13.88 gkg-1 , 水解氮105.00 ～ 490.00 mgkg-1 , 高低之差从几倍到近10倍;氮、磷、钾比例失调, 表现为氮质量分数过高, 而速效钾不足。②按南方耕地养分等级标准, 19 个香榧林地土壤样品中全氮和水解氮丰富至极丰富的有14 个, 缺乏的没有;全磷丰富、中等及缺乏的分别占8 , 7 和4 个;全钾丰富、中等和缺乏分别为2 , 9 和8 个;速效磷仅2 个样品缺乏, 而速效钾有17 个土样在中等水平以下。③按绿色食品产地养分等级标准, 则基本相似, 只是表现在有机质水平均在中等以下。这说明由于精细管理和大量施肥,使香榧林地氮磷钾质量分数总体提高, 但比例失调, 表现为多数土壤氮肥超标, 磷肥少数超标或不足, 多数土壤缺钾。在今后施肥中应注意控氮稳磷增钾, 做到平衡施肥。表4 参10
关键词:
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土壤学 /
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香榧 /
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成土母岩 /
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土壤类型 /
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土壤养分 /
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施肥
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 .]
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