中文摘要：

【目的】缓/控释氮肥的养分释放速率因介质而异,应根据作物种类、栽培模式及土壤等环境条件合理选择缓释肥类型。本试验以异丁叉二脲（IBDU）、硫包衣尿素（SCU）、脲甲醛（UF）、亚甲基脲（MU）、树脂包膜尿素（ESN）5种不同缓/控释氮肥为试材,通过研究在等养分水平下对基质栽培甜瓜生理特性及品质的影响,筛选出适宜基质栽培的缓/控释氮肥,以期为西北地区非耕地甜瓜的高品质、简约化栽培提供理论依据。【方法】采用基质盆栽（草炭∶蛭石∶珍珠岩=3∶1∶1,V∶V）试验,设CK（不施氮肥）、U（普通尿素）、IBDU、SCU、UF、MU和ESN 7个处理。幼苗长至23片真叶时,定植于高30 cm、直径30 cm的盆中,在甜瓜营养生长旺盛期即开花期取功能叶片进行生理生化指标的测定。【结果】与普通尿素相比,5种缓/控释氮肥可不同程度地提高甜瓜开花期叶片的叶绿素含量、净光合速率、蒸腾速率、氮含量和根系活力;缓/控释氮肥处理均能显著提高甜瓜单瓜重,有效改善甜瓜品质。效果表现为亚甲基脲（MU）〉异丁叉二脲（IBDU）〉脲甲醛（UF）〉树脂包膜（ESN）〉硫包衣尿素（SCU）,化学型缓/控释氮肥（MU、IBDU、UF）好于物理型缓/控释氮肥（ESN、SCU）。其中MU缓/控释氮肥处理的甜瓜叶片叶绿素a、叶绿素b和叶绿素a＋b含量分别较U处理增加了41.0%、31.0%和38.3%,叶片光合速率和蒸腾速率提高了28.9%和95.5%,叶片全氮、可溶性蛋白质、硝态氮含量分别增加了23.7%、24.3%、269.7%,根系活力提高了37.5%,果实单瓜重、中心可溶性固形物、可溶性糖、Vc含量分别提高了54.5%、4.1%、10.6%、16.7%,硝酸盐含量降低了9.9%。【结论】缓/控释氮肥可提高基质栽培甜瓜叶片的叶绿素含量,改善光合作用,增强甜瓜根系吸收功能,促进氮素的吸收和同化,进而提高产量和品质。缓/控释氮肥处理的甜瓜?

英文摘要：

【Objectives】Nutrient release rates of slow / controlled nitrogen fertilizers vary with different medium.Types of slow release fertilizers should be selected according to crop species, cultivation model and soil environment,etc. To provide theoretical basis for high quality and simplified cultivation of melon in non-cultivated land of northwestern China, effects of five controlled release nitrogen fertilizers, including Iso-butyl diurea（ IBDU）,sulfur-coated urea（ SCU）,urea formaldehyde（ UF）,methylene urea（ MU） and polyolefin-coated urea（ ESN）,on physiological characteristics and qualities of melon were investigated in special fertilizers at the same level of whole nutrients,and suitable slow / controlled release nitrogen fertilizer in substrate culture was screened.【Methods】Seven treatments were included in this study,namely,no N fertilizer treatment（ CK）,common urea（ U）,Iso-butyl diurea,sulfur-coated urea,urea formaldehyde,methylene urea and polyolefin-coated. At the twoleaf stage,muskmelon seedlings were transferred to pot（ height 30 cm,diameter 30 cm） within 5 kg substrate.One pot had one muskmelon seedling. The nutrient concentrations of substrate in a pot were N 7. 5g,P2O53. 25 g and K2 O 7. 5g. The formulation of matrix was peat ∶ vermiculite ∶ perlite = 3 ∶ 1 ∶ l（ in volume）. All the slow /controlled release nitrogen fertilizers were applied as basal fertilizers. For the common urea treatment,40% urea was used for basal application and 60% amount of urea was used as topdressing. Calcium superphosphate was supplied once at the beginning for all treatments. 40% potassium sulfate was fertilized as basal dressing and 60%used as top dressing. The top dressing was supplied at the fruit setting and fruit-development stages,and the same amount was applied for the two times. Leaf samples were collected randomly at the flowering stage of melon for testing. Three replicates for each treatment were laid out in a random design. 【Results 】 Compared with the ordinary