摘要：

为比较不同增效氮肥对苹果生长的影响,筛选适宜苹果施用的增效氮肥及施用方法,研究了4种不同增效氮肥对苹果生长、产量、品质及土壤氮素供应能力的影响。试验共设7个处理:不施氮肥(CK)、农民常规施用普通尿素(U)、包膜尿素与普通尿素3∶7掺混(CU1)、基施包膜尿素追施普通尿素(CU2)、控失尿素(KSU)、稳定性尿素(WDU)、腐植酸稳定性尿素(FZU)。在山东栖霞市布设田间试验,供试品种为6年生苹果金冠。结果表明,施用不同增效氮肥可显著促进春梢与秋梢生长,提高叶片SPAD、苹果产量与品质,其中FZU处理较U处理的产量显著提高了8.89%,CU1处理较U处理的果实Vc含量显著提高66.73%,CU1处理对春梢与秋梢的生长量的提高效果最明显。不同增效氮肥可显著提高苹果生育中后期的新梢氮素积累量、果实氮素积累量、氮肥农学效率、氮肥偏生产力和氮素利用率,其中在花芽分化期、膨果期和成熟期,FZU处理较U处理的新梢氮素积累量分别显著提高37.25%,15.91%,37.85%,CU2处理提高氮素利用率的效果最优。不同增效氮肥可显著提高土壤中 {\mathrm{NO}}_3^{-}-N、 {\mathrm{NH}}_4^{+}-N含量,其中FZU处理效果最优。FZU处理能提高开花期和花芽分化期土壤脲酶的活性,WDU与FZU处理可显著降低土壤 {\mathrm{NH}}_4^{+}-N的硝化作用,减少氮的损失。剖面中FZU处理的 {\mathrm{NO}}_3^{-}-N集中在20~60 cm深度,与苹果根系在土壤中的分布相符合,降低了 {\mathrm{NO}}_3^{-}-N淋溶风险。综合分析表明,FZU处理在促进苹果生长、提高苹果产量和改善土壤养分供应能力方面优势明显,为最优处理。

关键词: 苹果, 腐植酸尿素, 稳定性尿素, 控失尿素, 包膜尿素, 产量

Abstract:

To compare the effects of different nitrogen enhanced fertilizer on apple growth and to identify suitable nitrogen enhanced fertilizer and application methods for apple cultivation,this study examined the impact of four different types of nitrogen enhanced fertilizer on apple growth,yield,quality,and soil nitrogen supply capacity.The experiment consisted of seven treatments:no nitrogen fertilizer(CK),regular application of ordinary urea by farmers(U),coated urea mixed with ordinary urea 3∶7(CU1),basal application of coated urea and follow-up application of ordinary urea(CU2),loss-control urea(KSU),stabilizing urea(WDU),and humic acid stabilizing urea(FZU).A field experiment was conducted in Qixia City,Shandong Province,to analyze the effects of different fertilization treatments on the growth,yield,and quality of 6-year-old Golden Crown apple trees,as well as nitrogen utilization and soil nitrogen supply capacity.The results demonstrated that the application of diverse synergistic nitrogen fertilizers could markedly enhance spring and autumn growth,elevate leaf SPAD,and enhance apple yield and quality.Among these,the yield of the FZU treatment exhibited a significant increase of 8.89% in comparison to that of the control.The Vc content of the fruits of the CU1 treatment was found to be significantly increased by 66.73% in comparison to the U treatment.Furthermore,the CU1 treatment demonstrated the most pronounced impact on the improvement of growth in both spring and autumn.Nitrogen enhanced fertilizer had been demonstrated to significantly enhance nitrogen accumulation in new shoots and fruit nitrogen accumulation,nitrogen fertilizer agronomic efficiency,nitrogen fertilizer bias productivity and nitrogen utilization in the middle and late stages of apple fertility.Of these,the FZU treatment had been observed to exert the most pronounced effect.The nitrogen accumulation of new shoots in FZU treatment was significantly increased by 37.25%,15.91% and 37.85% compared with that in U treatment at bud differentiation,fruiting and ripening stages,respectively.The CU2 treatment was found to have the most beneficial effect on nitrogen utilization.Nitrogen enhanced fertilizer treatments demonstrated the capacity to significantly enhance the nitrate and ammonium content of soil.Among these treatments,the FZU treatment exhibited the most pronounced effect.The FZU treatment was observed to enhance soil urease activity during the flowering and bud differentiation stages.Additionally,the WDU and FZU treatments were found to significantly reduce the nitrification of soil ammonium and nitrogen loss.The {\mathrm{NO}}_3^{-}-N of the FZU treatment was concentrated at a depth of 20—60 cm soil,which was consistent with the distribution of apple roots in the soil and reduced the risk of {\mathrm{NO}}_3^{-}-N leaching.A comprehensive analysis demonstrated that the FZU treatment exhibited clear advantages in promoting apple growth,increasing apple yield and quality,and enhancing soil nutrient supply capacity.Consequently,the FZU treatment was identified as the optimal treatment.

Key words: Apple, Humic acid urea, Stabilizing urea, Loss-controlling urea, Coating urea, Yield