配方施肥对华北落叶松叶枝根及土壤氮磷钾及计量比的影响

Effect of formulated fertilizer application on N,P,K and stoichiometry ratios of leaves,branches,roots and soils of Larix principis-rupprechtii

【目的】探究配方施肥对华北落叶松针叶、枝条、细根及土壤氮磷钾含量及计量比的影响及相关关系,为华北落叶松高效施肥技术提供理论参考。【方法】本研究以32年生的华北落叶松为试验材料,采用N、P、K三因素三水平正交试验L9(34),以不施肥为空白(CK),分析配方施肥对华北落叶松针叶、枝条、细根及土壤氮磷钾含量及计量比的影响。【结果】1)与CK相比,各施肥处理显著促进华北落叶松的生长,树高和胸径的增长量均在处理T6达到峰值,高出CK 95%、156%;各施肥处理显著提高土壤TN、TP、TK含量(P<0.05),分别以处理T8、T9和T6效果最佳,增加了91.1%、28.5%、4.3%。2)各施肥处理均能有效提高细根N、P、K含量、枝条N、P含量、针叶N含量,而降低针叶P、K含量和枝条K含量,且各处理与CK间差异显著(P<0.05)。3)氮磷钾配比施肥对各器官及土壤的化学计量比具有显著影响(P<0.05),其中各器官及土壤N∶P<14,针叶、枝及土壤中N∶K<2.1、K∶P>3.4,而细根相反。(4)相关性分析表明:土壤与细根养分含量之间呈显著负相关(P<0.05)、与针叶N含量呈显著正相关(P<0.05);针叶和枝条的P、K含量均呈极显著正相关(P<0.01),枝条和细根的N、P、K含量均呈极显著正相关(P<0.01)。5)方差分析结果表明:氮是肥料3因素中影响华北落叶松各器官及土壤养分含量的主要因素;多重比较表明:氮素水平对华北落叶松各器官及土壤养分含量均产生显著影响,磷和钾素水平对各指标显著性影响不同;主成分分析表明:适宜改善华北落叶松各器官及土壤养分含量的最佳氮磷钾配施方案为N2P3K1(N 352.52 g·株-1、P 1621.58 g·株-1、K 86.48 g·株-1)。【结论】华北落叶松针叶、枝条及土壤的养分变化主要受到N和P的限制,细根受到N和K的限制;施肥能够改善华北落叶松生长环境的养分含量,该研究结果可为华北落叶松高效施肥技术提供参考依据。

【Objective】To investigate the effect of formula fertilizer application on the content of leaves,branches,roots and soil nitrogen,phosphorus and potassium and the related relationship,and to provide theoretical reference for the efficient fertilization technology of Larix principis-rupprechtii.【Method】In this study,32-year-old L.principis-rupprechtii was used as experimental material,using N,P,K three-level orthogonal experiment L9(34),with no fertilization as blank(CK),to analyze the effects of formula fertilization on leaves,branches,roots and soil nitrogen,phosphorus and potassium content and stoichiometric ratio in L.principisrupprechtii.【Result】1)Compared with CK,fertilization treatments significantly promoted the growth of L.principis-rupprechtii,and the growth of both tree height and diameter at breast height peaked at treatment T6,which was 95%and 156%higher than that of CK.The contents of TN,TP and TK in soil were significantly increased in all fertilization treatments,and the effects of treatments T8,T9 and T6 were the best,which increased by 91.1%,28.5%and 4.3%,respectively.2)All fertilization treatments could effectively increase the contents of N,P and K in roots,branches and leaves,while decrease the contents of P,K in leaves and K in branches,and there is significant difference between each treatment and CK.3)The ratio of N,P and K have a significant effect on the stoichiometric ratio of organs and soil(P<0.05),in which N:P of each organ and soil was less than 14,N:K of leaves,branches and soil was less than 2.1,K:P was more than 3.4,while root was on the contrary.4)Correlation analysis showed that there was a significant negative correlation between soil and root nutrient content(P<0.05),a significant positive correlation with leaf N content(P<0.05);an extremely significant positive correlation between leaves and branches P and K content(P<0.01),and an extremely significant positive correlation between branches and roots N,P,K content(P<0.01).5)The analysis of variance showed that nitrogen was the main factor affecting the nutrient content of each organ and soil of L.principis-rupprechtii,and had a significant effect on each organ and soil nutrient content of L.principis-rupprechtii(P<0.05).Multiple comparisons showed that nitrogen levels had significant effects on the nutrient contents of organs and soil of L.principis-rupprechtii,and the levels of phosphorus and potassium had different effects on each index.Principal component analysis showed that the best combined application scheme of nitrogen,phosphorus and potassium fertilizer to improve the nutrient content of L.principis-rupprechtii organs and soil was N2P3K1(N 352.52 g plant-1,P 1621.58 g plant-1,K 86.48 g plant-1).【Conclusion】Nutrient changes in leaves,branches,and soil of L.principis-rupprechtii are mainly limited by N and P,and roots are limited by N and K.Fertilization can improve the nutrient content of L.principis-rupprechtii growth environment and the research results provide a reference basis for efficient fertilization technology of L.principis-rupprechtii.