不同肥料组合对莴笋产量和品质的影响

采用田间小区试验研究了不同肥料组合对莴笋产量、品质和叶片养分形态的影响。结果表明,在施入等量氮肥的基础上,磷、钾、中量及微量元素和有机肥料平衡施用使莴笋极显著增产(135·8%~177·0%),其增产序列依次为NP1K2MgZnB>NP2K2>NP1K2RM>NP1K2PP>NP1K2Mg>NP1K2>NP2K1。不同肥料组合可降低莴笋叶片硝酸盐含量,以NP1K2MgZnB处理降低量最大,降低最少者为NP2K2处理;茎中硝酸盐含量以NP1K2RM处理降低量最大,NP2K1处理降低最小。肥料组合各处理对莴笋营养品质Vc和氨基酸以提高作用为主,以NP1K2MgZnB处理对莴笋产量和品质的效应最好。莴笋叶片养分形态中,氮素以蛋白氮为主,磷素和钾素分别以非蛋白磷和非蛋白钾为主。不同肥料组合对莴笋叶片氮和磷素形态的效应不一致,对3种钾形态均有提高作用。各养分形态中,氮素仅非蛋白氮与茎硝酸盐呈显著负相关,与茎Vc呈显著正相关,与叶氨基酸呈极显著正相关;磷素以非蛋白磷与叶Vc、茎氨基酸呈显著负相关;钾素的非蛋白钾和全钾与叶硝酸盐呈显著负相关,与茎硝酸盐为极显著负相关,与叶Vc、茎Vc呈显著正相关,与茎氨基酸呈极著正相关,蛋白钾与茎硝酸盐呈极显著负相关,与叶Vc、茎Vc、茎氨基酸呈显著正相关,与叶氨基酸呈极著正相关。

EFFECTS OF FERTILIZER COMBINATION ON YIELD AND QUALITY OF LETTUCE

A field experiment was conducted to study effects of fertilizer combination on yield,quality and forms of nutrients in leaf of lettuce.The results show that yield of lettuce was significantly increased(135.8% ~177.0% ) by balanced application of secondary-and micro-nutrient fertilizer and organic fertilizer in addition to N application at the same rate in CK.In terms of yield increment,the treatments were in the sequence of NP₁K₂MgZnB>NP₂K₂>NP₁K₂RM>NP₁K₂PP>NP₁K₂Mg>NP₁K₂>NP₂K₁.Nitrate contents of lettuce were reduced in all treatments.It was the most significant in Treatment NP₁K₂MgZnB and the least in Treatment NP₂K₂ in leaf,and the most in Treatment NP₁K₂RM and the least in Treatment NP₂K₂ in stem.Quality of the lettuce was improved in all the treatments and the most in Treatment NP₁K₂RM.In terms of forms of nutrients in the plant,protein-N,non-protein-P and non-protein-K dominate,respectively,in the lettuce leaf.Effects of fertilizer combination on forms of N and P nutrients in the leaf of lettuce differed from treatment to treatment but the effects of raising contents of the three forms of potassium were similar.Among the forms of nutrients,only non-protein-N showed a significantly negative correlat ion with nitrate in the stem of lettuce,but a positive one with Vc content in the stem and amino acid content in the leaf,non-protein-P showed a significantly negative correlation with Vc in the leaf and amino acid in the stem,and non-protein K and total K showed a significantly negative correlation with nitrate in the leaf but a positive one with Vc contents in the stem and leaf and amino acid in stem.Protein K showed a significantly negative correlation with nitrate in the stem,but a positive one with Vc and amino acid in the stem and leaf.