Taking a six-year old 'Orin' apple tree plantation ('Orin'/SH6/ Malus micromalus Makino) as test material, the effects of common urea treatment (CU), bag-controlled release ferti-lizers treatment (BCRF) and controlled-release nitrogen fertilizer treatment (CRNF) on 15N-urea absorption, utilization, loss and accumulation dynamics of nitrogen content in 0-80 cm soil layer were investigated by 15N labeled tracer method. The results showed that compared with CU treatment, both CRNF and BCRF treatments increased the inorganic nitrogen content in soil at the late stage of apple growth, the leaf SPAD value, leaf nitrogen content, net photosynthetic rate and 15N derived from fertilizer (Ndff value) of different organs at fruit maturity stage, with CRNF showing stronger effects than BCRF. The amount of 15N residue in 0-40 cm soil layer showed a decreasing trend in different phenological stages. The amount of 15N residue was the highest in CRNF, followed by BCRF, and the lowest in CU, among which CRNF declined gently with 15N residue mainly concentrated in the 0-40 cm soil layer. 15N residue in 40-80 cm soil layer showed an increasing trend in different phenological stages, which was the highest in CU, followed by BCRF, and the lowest in CRNF, and that of CRNF increased gently. The 15N fertilizer utilization rate of CRNF was 32.6% at fruit maturity stage, which was 1.11 and 1.56 times as high as that of BCRF and CU, whereas its 15N loss rate was 21.6%, being obviously lower than BCRF (35.6%) and CU (59.6%). CRNF significantly improved fruit yield and quality and increased economic benefits.
以6年生‘王林’/SH6/八棱海棠为试验材料,采用15N同位素示踪技术,研究了普通尿素(CU)、袋控缓释肥(BCRF)和控释氮肥(CRNF)对15N-尿素吸收、利用、损失和0～80 cm土层氮素累积动态的影响.结果表明: CRNF和BCRF处理较CU处理均明显提高了苹果生长后期土壤无机氮含量、果实成熟期叶片的SPAD值、氮含量、净光合速率和植株各器官对氮的吸收能力(Ndff值),但CRNF影响更显著.在0～40 cm土层不同物候期15N残留量呈降低趋势,均以CRNR最高,BCRF次之,CU最低,且CRNF降幅平缓,15N残留量主要集中在0～40 cm土层;在40～80 cm 土层不同物候期15N残留量呈增加趋势,均以CU最高,BCRF次之,CRNF最低,且CRNF增幅平缓.在果实成熟期,CRNF的15N肥料利用率为32.6%,分别是BCRF和CU 的1.11、1.56倍,而15N损失率为21.6%,显著低于BCRF(35.6%)和CU(59.6%).CRNF显著提高了果实产量,改善了果实品质,增加了经济效益.
Keywords: 15 N-urea; apple; bag-controlled release fertilizer; controlled-release nitrogen fertilizer.