橡胶树幼苗对不同品种氮肥的吸收、利用与分配

Absorption, Distribution and Utilization of Different Nitrogen Fertilizers in Rubber Tree Seedlings

采用^15N示踪盆栽试验研究橡胶树（Hevea brasiliensis）幼苗对尿素、硫酸铵、硝酸钙及硝酸铵等4种氮肥的吸收、利用和分配特征。结果表明：4种氮肥处理植株不同部位的^15N丰度平均值介于1.04%-1.37%,橡胶树幼苗各器官氮素含量来自肥料氮的百分比（Ndff%）介于27.64%-41.70%,^15N丰度和Ndff%均以硝酸钙处理最高,尿素处理最低;不同器官相比较,以韧皮部最高,主茎、主茎皮和细根次之,粗根、叶片和叶柄最低。4种肥料的利用率无显著差别,而残留率以尿素最低,硫酸铵最高;损失率以尿素最高,硫酸铵最低。综上所述,尿素的损失率高,橡胶树幼苗对尿素的吸收性较差,而对硝酸钙和硝酸铵具有较好的吸收性。

A pot experiment was carried out to study absorption, utilization and distribution of different nitrogen fertilizers in rubber tree（Hevea brasiliensis） seedlings, in which ^15N labeled nitrogen fertilizers such as CO（^15NH2）2,（^15NH4）2SO4, Ca（^15NO3）2 and ^15NH4^15NO3were used. The results showed that ^15N abundance in rubber seedlings of the 4 treatments ranged from 1.04% to 1.37%. The proportion of N derived from fertilizer（Ndff%） in the organs of rubber seedling were between 27.64% and 41.70%. The highest15 N abundance and Ndff% were observed in the treatment of Ca（NO3）2, while urea treatment had the lowest value. ^15N abundance and Ndff% value in phloem were the highest, followed with stem, stem bark and fine roots, lower values were found in taproot, leaf and leafstalk. The utilization efficiency of 4 N fertilizers had no significant difference. The residual rate of urea was the lowest among 4 treatments, while the highest residual rate was observed in（NH4）2SO4 treatment. In contrast to residual rate, the loss rate of urea was the highest, and（NH4）2SO4treatment had lowest loss rate. The results indicated that urea was easy to lose, and rubber seedling prefer to absorb and utilize N of Ca（NO3）2 and NH4NO3 than absorb N of urea. This was worth thoroughly studying.