配施NBPT下氮肥减施对大蒜生物量及氮代谢的影响

Effects of Combined Application of NBPT and Reducing Nitrogen Fertilizer on Garlic Biomass Accumulation and Nitrogen Metabolism

以大蒜品种“徐蒜917”为试材,设置PK(CK1)、NPK(CK2)、90%N+PK+NBPT(T1)、80%N+PK+NBPT(T2)、70%N+PK+NBPT(T3)、60%N+PK+NBPT(T4)共6个处理,探讨了减施氮肥+配施NBPT对大蒜生物量积累及氮代谢的影响。结果显示:N与NBPT配施时,大蒜各器官的干物质量随氮肥减施基本上呈先增后降的趋势,以T2较高,且T2处理的叶片色素含量与CK2无显著差异;叶片和根系中NR和GOGAT活性随氮肥减施均呈先增后降的趋势;叶片中GS活性随氮肥减施呈下降趋势,而根系中GS活性呈先升后降的趋势;叶片和根系中NO 3-和NH 4+含量与施氮量呈正相关;T2处理较CK2显著增加了叶片中可溶性蛋白含量;随氮肥减施,叶片中游离氨基酸和脯氨酸含量总体呈下降趋势,而根系中游离氨基酸含量呈先增后降的趋势。因此,氮肥与NBPT配施可有效延缓尿素的水解,减轻氮肥减施对大蒜干物质量及氮代谢的不利影响。

In order to investigate the effects of nitrogen fertilizer reduction and combined application of NBPT on garlic biomass accumulation and nitrogen metabolism,the garlic(Allium sativum L.)cultivar“Xusuan 917”was used as the test material,and six treatments were set as follows:PK(CK1),NPK(CK2),90%N+PK+NBPT(T1),80%N+PK+NBPT(T2),70%N+PK+NBPT(T3),60%N+PK+NBPT(T4).The results showed that the dry matter mass of garlic each organ increased first and then decreased with the decrease of nitrogen fertilizer when NBPT was applied,and they were better mostly under T2 treatment,and the leaves pigment content was not significantly different between CK2 and T2.The NR and GOGAT activity in leaves and roots increased first and then decreased with the decrease of nitrogen fertilizer.GS activity in leaves showed a downward trend,while in root it increased first and then decreased.The NO 3-and NH 4+contents in leaves and roots were positively correlated with the amount of nitrogen applied.T2 significantly increased soluble protein content in leaves.With the decrease of nitrogen fertilizer,the free amino acid content in leaves showed a downward trend,while it increased first and then decreased in root.In summary,the combined application of nitrogen fertilizer and NBPT could effectively delay urea hydrolysis and reduce the disadvantageous effect of the decrease of nitrogen fertilizer on the quality of garlic dry matter and nitrogen metabolism.