施肥对盆栽杉木苗土壤养分含量的影响

研究施肥对1年生(1 a)与2年生(2 a)杉木苗盆栽土壤养分含量的影响.结果表明:在氮、磷营养亏缺的酸性黄红壤上,随着氮肥施用量的增加,1 a苗木盆栽土壤pH值、全钾含量下降,全氮、水解氮、水溶性钙镁含量增加,全磷、有效磷、速效钾变化不明显.由于局部尿素浓度过大直接导致幼苗受伤,影响了成活率.而2 a苗木的土壤则是全氮、水解氮、水溶性钙镁含量呈上升趋势,全钾、速效钾含量和pH值下降,有机质和全磷含量变化不明显.有效磷含量与pH值呈明显负相关,表明pH值下降导致闭蓄态磷活化,促进了2 a苗木的生长.在氮、磷营养亏缺条件下,施磷量的增加使得1 a苗木土壤全磷、有效磷、速效钾含量、pH值增加,全钾、水溶性钙镁含量则下降,有机质、水解氮没有明显变化.养分含量与生长指标的相关分析表明:施用磷肥解除了1 a苗木磷素营养亏缺,显著促进了苗木生长;而对2 a苗木,施磷肥使土壤中的全磷、有效磷增加,全钾含量下降,pH值、有机质、全氮、速效钾、水溶性钙镁没有明显变化.对养分含量与生长指标的相关分析表明:施磷肥对2 a苗木生长没有促进作用,而且使土壤营养平衡进一步失调,苗木仍处于营养亏缺状态.在氮素营养充足、磷素亏缺的营养条件下,随着氮磷复合肥施肥量的增加,2 a苗木中的全氮、全磷、水解氮、有效磷增加,速效钾含量下降.施用氮磷复合肥可促进苗木对速效钾的吸收利用,导致苗木的光合产物向叶和茎部转移.

Effects of Fertilization on Soil Nutrient Content of Potted Chinese Fir Seedling

The purpose of this study was to illustrate the effects of some fertilizers on the soil nutrient content of one_year_old (1 a) and two_year_old (2 a) potted seedlings. The results showed that: on the N_deficient and P_deficient acidic soil, with the increase of N fertilizer on 1 a seedlings, obvious changes in the soil nutrient contents were observed. pH and total potassium content (TK) went down, while the concentration of total nitrogen (TN), hydrolytic nitrogen (HN), water_soluble calcium (Ca) and water_soluble magnesium (Mg) rose up. The variation of total phosphorus (TP), availabe_P(AP), rapidly_available potassium (AK) was unnoted. Some of 1a seedlings were damaged by the overhigh of N concentration. For 2 a seedlings, TN, HN, Ca, and Mg in soil went upward with the increase of N fertilizer, while TK, AK and pH dropped. The change of organic matter and TP was not significant. Differed from 1 a seedlings,the decrease of pH activated the occluded phosphorus and led to the increase of AP, which was good for the growth of the 2 a seedlings. Under the N_deficient and P_deficient conditions, TP, AP, AK and pH went up, while TK, Ca and Mg fell down. But no remarkable change took place for organic matter and HN. The correlation analysis between soil nutrient content and growth indexes indicated that the application of P fertilizer eliminated the P stress and accelerated the growth rate of the 1 a seedlings. For the 2 a seedlings, the gradual increase of P fertilizer made TP, AP ascend and TK descend, but pH, organic matter, TN, AK, Ca and Mg had no notable change. The correlation analysis showed that the use of P fertilizer caused soil nutrition imbalance instead of improving the growth status. The 2 a seedlings were still in the situation of nutrition deficiency. On the N_adequate and P_deficient soil, with the increase of NP compound fertilizer applied to the 2 a seedlings, TN, TP, HN and AP in seedlings climbed up and AK went down. According to the correlation analysis, application of NP compound fertilizer to the 2 a seedlings could enhance the absorption and utilization of AK, resulting the transference of photosynthetic production from leaves to roots, therefore accelerate the growth rate greatly.