氮肥对杉木幼树各部分养分浓度与贮量的影响

Effects of nitrogen fertilizer on nutrient concentration and storage in different parts of young Chinese fir

采用田间试验和定位的方法,研究氮肥对杉木幼树各部位生物量积累及养分浓度与贮量的影响。结果表明:(1)杉木幼树施用氮肥有利于其生物量的提高,较不施氮对照增加58.29%,其中树根增幅最高,达到113.17%;(2)无论对照还是施氮处理,叶片和韧皮部中各元素浓度均高于木质部,且前两者的元素浓度变化幅度也大于后者;(3)与对照相比,施用氮肥可提高杉木幼树各部位N、P、K、Ca和Mg的贮量,其中提高最为显著的部位是细根,而叶片是最大的元素贮量库;(4)施用氮肥可以增加叶片和皮质部中各养分贮量在全树养分中所占的比例,进而增加养分外循环通量。

Effects of N fertilizer on biomass accumulation,nutrient concentration and storage of different parts of young Chinese fir were studied by field trial and positional method.The results show that(1) Comparing with the control,the biomass of young Chinese fir increased by 58.29% with application of N fertilizer,and the biggest increment was in roots,which was 113.17%.Ratio of trunk,coarse and fine root bark to total tree were higher under control treatment than fertilization treatment.(2) Whether the control or N treatment,the element concentrations of leaves and the cortex were higher than the core material,and the two former were greater than the latter to variation range of elemental concentration;(3) N fertilization could improve storage of N,P,K,Ca and Mg in all parts of Chinese fir compared with the control,which increased most significantly in fine roots,and leaves were the largest storage library of element.(4) The application of N fertilizer could increase the ratio of the cortical part and leaf to the whole tree in nutrient storage,leading to increment of nutrient flux in the external circle.