A split-field design experiment was carried out using two main methods of cultivation (grafting and self-rooted cultivation) and subplots with different nitrogen application levels (0, 120, 240, and 360 kg N·hm-2) to investigate the effects of cultivation method and nitrogen application levels on the yield and quality of melons, nitrogen transfer, nitrogen distribution, and nitrogen utilization rate. The results showed that melons produced by grafting cultivation had a 7.3% increase in yield and a 0.16%-3.28% decrease in soluble solid content, compared to those produced by self-rooted cultivation. The amount of nitrogen accumulated in melons grafted in the early growth phase was lower than that in self-rooted melons, and higher after fruiting. During harvest, nitrogen accumulation amount in grafted melon plants was 5.2% higher than that in self-rooted plants and nitrogen accumulation amount in fruits was 10.3% higher. Grafting cultivation increased the amount of nitrogen transfer from plants to fruits by 20.9% compared to self-rooted cultivation. Nitrogen distribution in fruits was >80% in grafted melons, whereas that in self-rooted melons was <80%. Under the same level of nitrogen fertilization, melons cultivated by grafting showed 1.3%-4.2% increase in nitrogen absorption and utilization rate, 2.73-5.56 kg·kg-1 increase in nitrogen agronomic efficiency, and 7.39-16.18 kg·kg-1 increase in nitrogen physiological efficiency, compared to self-rooted cultivation. On the basis of the combined perspective of commercial melon yield, and nitrogen absorption and utilization rate, an applied nitrogen amount of 240 kg·hm-2 is most suitable for graf-ting cultivation in this region.
通过裂区设计田间试验,主区为2种栽培方式(嫁接栽培和自根栽培),副区为4个施氮水平(0、120、240、360 kg N·hm-2),研究了栽培方式和施氮量对甜瓜产量和品质、氮素运移和分配,以及氮素利用率的影响.结果表明: 嫁接栽培的甜瓜商品瓜产量较自根甜瓜提高了7.3%,可溶性固形物含量降低了0.16%～3.28%;生长前期嫁接栽培甜瓜氮素累积量较自根栽培低,结果后嫁接栽培氮素累积量显著升高,收获时植株氮素累积量较自根栽培增加了5.2%,果实中的氮素累积量提高了10.3%;嫁接栽培植株氮素向果实的转移量较自根栽培提高了20.9%,嫁接栽培果实中的氮素分配率在80%以上,自根栽培的分配率在80%以下;在同一施氮水平下,嫁接栽培的甜瓜氮素吸收利用率较自根栽培提高了1.3%～4.2%,氮素农学效率提高了2.73～5.56 kg·kg-1,氮素生理利用率提高了7.39～16.18 kg·kg-1;从商品瓜产量、氮素吸收量和氮素利用率综合考虑,施氮量240 kg·hm-2为本区域嫁接甜瓜较适宜的氮素用量.
Keywords: melon; nitrogen distribution; nitrogen transfer; nitrogen utilization rate.