不同土壤和氮钾肥配比对莴笋的营养效应研究

Effect of Nitrogen and Potassium Fertilizers on Yield and Quality of Lettuce in Different Soils

通过田间小区试验研究了不同N、K肥料配比对酸性和碱性土壤上两个莴笋品种(科兴3号和双尖莴笋)产量及品质的影响。结果表明,不同土壤上施用不同N、K配比肥料对双尖莴笋和科兴3号的产量影响不同。在酸性土壤上,对照(N15K10)是适宜两种莴笋高产的最佳N、K肥配比处理。在碱性土壤上种植双尖莴笋时,可以考虑在对照基础上适当地降低N肥用量。在碱性土壤上两种莴笋的产量均高于酸性土壤。减N和增K处理有利于降低莴笋的硝酸盐含量。在酸性土壤上莴笋中的硝酸盐含量高于碱性土壤。莴笋采收后期茎的硝酸盐含量高于叶片。不同施肥处理对两种土壤上科兴3号和双尖莴笋营养品质的作用不一致。在酸性土壤上增施K肥或提高N肥的用量对莴笋营养品质的改善更有效果。莴笋的Vc含量以叶片>茎,且酸性土壤>碱性土壤。除双尖莴笋在增K处理(N15K15、N20K15)中茎的可溶性糖含量表现为酸性土<碱性土以外,其他处理莴笋茎叶中的可溶性糖均为酸性土>碱性土。不同处理莴笋的氨基酸含量均表现为茎>叶。

The effect of the combination of nitrogen and potassium fertilizers on yield and quality of lettuces (Kexing No. 3 and Doubletip lettuce) in two kinds of soils were studied by the field experiment. The results showed that there was significant difference between the yields of two lettuces. To the acid soil, the CK treatment(N15K10)was the best to gain the high yield of lettuces, but nitrogenous fertilizer could be reduced appropriately for Doubletip lettuce in the alkali soil. The yields of two lettuces in the alkali soil were higher than in the acid one. Decreasing nitrogen or increasing potassium fertilizer reduced the content of nitrate of lettuces. The nitrate content was higher in stem than leaf in harvest anaphase, and higher in acidic soil than in alkali one. The effect of nitrogen and potassium fertilizers on nutrient quality of two lettuces were different, increasing potassium or nitrogenous fertilizer was more effective in acid soil than in alkali one. The contents of Vc in two lettuces were higher in leaf than in stem, higher in acidic soil than in alkali soil. The contents of soluble sugar in two lettuces were higher in acidic soil than in alkali soil except the stem of Doubletip lettuce in increasing K treat. The contents of amino acid in two lettuces were higher in stem than leaf.