【作者】 苏天明；

【导师】 顾明华；

【作者基本信息】 广西大学 ， 植物营养学， 2004， 硕士

【摘要】 为了有效地控制蔬菜中的硝酸盐积累，本论文以菜心为材料，以甘蔗渣为基质，研究了在大棚无土栽培条件下，施N量、N肥品种和等N条件下尿素配施不同比例的氯化铵对菜心硝酸盐积累的影响及其机理，并采用“416-B”最优混合设计研究N、P、K、Cl配比对菜心产量和硝酸盐积累的效应及其最佳配比。研究结果表明： 1．随着N肥（尿素）用量的增加，菜心经济产量增加，但产量的增加幅度随着N肥用量的增加而降低。菜心经济产量部分全氮含量和硝酸盐含量随N肥用量增加而增加。增加低水平的纯氮(≤15.5g·treatment^-1)时，能提高硝酸还原酶活性；增加高水平的氮(＞15.5g·treatment^-1)时，硝酸还原酶活性变化不显著。 2．与施用尿素相比较，施用等N量的[60％（NH₄）₂SO₄+40％NH₄Cl]和NH₄Cl能显著地降低菜心硝酸盐含量。但同时也显著地降低产量，这可能是因为NH₄⁺或Cl^-浓度过高的缘故。不同N肥品种处理间，菜心全N、P含量无明显差异，说明施用不同N肥品种不会对菜心N、P营养状况产生明显的影响。 3．尿素与氯化铵配合施用能显著地降低菜心硝酸盐含量，降低效应随着配施氯化铵比例的增加而增加。其原因在于氯化铵能显著减少栽培基质中亚硝酸细菌的数量，抑制硝化作用的进行。与单独施用广西大学硕士毕业论文施肥技术对调控菜心硝酸盐积累的效应研究尿素处理相比较，（60%尿素+40%氯化按）处理菜心产量没有产生显著性差异，（20%尿素十80%氯化铁）处理在生长前期对菜心生物产量没有显著影响，但是在收获时产量明显降低，比尿素处理降低了5 .6%。 4.N、P、K、Cl合理配施能提高菜心产量，降低菜心硝酸盐含量。其中N、P、K与产量呈正效应，Cl与产量呈负效应，N与菜心硝酸盐含量呈正效应，P、K、Cl与菜心硝酸盐含量呈负效应。结合菜心产量、硝酸盐含量和Vc含量综合考虑，确定高产优质菜心的最佳营养配方，N、P、K、CI的编码值（真实值）分别为0.49（1 8.58）、1.49（8.95）、1.16（22.11）、0.23（33.31），对应的产量为707.12g·treatment一’Fw，硝酸盐含量为6 1 2.01 mg·kg一，Fw，vc含量为170.42mg·kg一IFw。更多还原

【Abstract】 In order to control the nitrate accumulation in vegetable effectively, using the bagasse in greenhouse, studies were carried on about the effects of different N application, different N fertilization forms, urea arranged different percentages of ammonium chloride with equal N, and N-P-K-C1 compound treatment with optimal compound design"416-B" on the yield and nitrate content of the flowering Chinese cabbage. So the optimal nutrient formulation of N-P-K-C1 compound treatment was found. The results are as follows:1. With the increase of N (Urea) application, economical yield of the flowering Chinese cabbage enhances too. But the extent of increasing in economical yield become smaller when the N (Urea) application is increased. The content of total N and nitrate follow the raise of N (Urea)applied. Increasing lower level N application ( 15.5g-treatment~’) can highen the NRA. But, increasing higher level N application ( 15.5g-treatment~’) can change the NRA little.2. Among the three treatments with equal N application, the treatments of [60%(NH4)2SO4+40%NH4C1] and NHtCl would reduce nitrate content in economical yield part of the same vegetable obviously compared to the treatment of Urea. But at the same time, the economical yield drop too likely because of the redundant NH4+ or Cl content. The total N, P content of the flowering Chinese cabbage are no obvious differences under all treatments of different N fertilization forms, it shows that the treatments of different N fertilization forms can’t bring about distinct changes about the content of total N, P.3. The use of Urea- NH4Cl compound treatment will read to evident cut down of nitrate content in the flowering Chinese cabbage, the bigger the percentige of NH4C1 is used, the bigger the extent of drop about nitrate content become. The reason lies in the Cl. It would reduce the number of nitrous acid bacterium and then hold back the nitrification in bagasse obviously. The yields of the flowering Chinese cabbage are no obvious differences between the treatments of [60%Urea +40% NH4C1] and single urea. The treatment of [20%Urea +80% NH4Cl] could not result in evident change about the yield during the early lifetime. But on the harvest day, the yield cut down evidently, the extent of drop is 5.6%compared to the treatment of urea.4. The reasonable use of N, P, K, Cl coupund treatment can make the economical yield become bigger while the nitrate content in economical yield part become smaller. The increase of N, P, K applied can enhance the economical yield, but the increase of Cl application can reduce it; Besides, the use of N can increases the nitrate content in economical yield part, but the use of P, K, Cl can make the nitrate content in economical yield part become smaller. For the consideration of the yield, nitrate content and Vc content in economical yield part, The optimal nutrient formulation has been drafted, the coded date (true date) of N, P, K, Cl are listed separately: 0.49 (18.58 g-treatment-1) , 1.49 (8.95 g treatment-1) , 1.16 (22.11 g-treatment-1 ), 0.23 (33.31 g-treatment-1) . At the same time, the economical yield is 707.12 g-treatment-1, the nitrate content in economical yield part is 612.01 mg-kg-1FW, the Vc content is 170.42 mg-kg-1FW.更多还原