【作者】 肖时运；

【导师】 刘强；

【作者基本信息】 湖南农业大学 ， 植物学， 2006， 博士

【摘要】 为开发和推广蔬菜有机-无机专用复混肥，本文采用盆栽试验和¹⁵N标记示踪技术探讨了化学氮肥用量对4种蔬菜（蕹菜、莴苣、小白菜、萝卜）产量、品质（硝酸盐、蛋白质、可溶性糖、粗纤维、维生素C含量）及氮肥利用率的影响，在保证蔬菜高产、优质、低污染的前提下，权衡化学氮肥用量与蔬菜产量、品质和化学氮肥利用率之间的关系，得到了4种蔬菜合理的化学氮肥用量。在此基础上，采用田间小区试验探讨了有机-无机复混肥对莴苣和小白菜叶片光合特性，C、N代谢关键酶活性，产量及品质（维生素C、可溶性糖、硝酸盐、亚硝酸盐、粗纤维及部分氨基酸含量）的影响。试验结果如下：1．化学氮肥用量x（尿素千克／盆）与蔬菜产量（?）（千克／盆）之间的关系可用一元二次回归方程来表示：蕹菜，鲜重：（?）=-14816x²+85.496x+0.0149；莴苣，鲜重：（?）=-25951x²+175.23x+0.1042；小白菜，鲜重：（?）=-16647x²+113.93x+0.0133；萝卜，鲜重：（?）=-41666x²+225.75x+0.0311。4种蔬菜产量均随化学氮肥用量的增加而增加，但超过一定化学氮肥用量后，产量反而下降。合理的化学氮肥用量能提高蔬菜的产量。2．在一定的化学氮肥用量范围内蔬菜可食部分的Vc含量随氮肥用量的增加而增加，超过一定的化学氮肥用量后便随氮肥用量的增加而减少。适宜的化学氮肥用量能提高蔬菜Vc含量，促进蔬菜蛋白质的合成与累积，增加蔬菜可溶性糖含量，提高蔬菜功能叶叶绿素含量，延长蔬菜功能叶的功能期，增强蔬菜NR的活性，降低蔬菜硝酸盐的积累，改善蔬菜可食部分的内在品质与口感。3．蔬菜植株总吸氮量随化学氮肥用量的增加而增加，植株¹⁵N丰度含量也随化学氮肥用量的增加而增加。合理的施用化学氮肥，既可提高蔬菜对化学氮肥的吸收量，又能促进蔬菜植株吸取更多的土壤氮。化学氮肥在蔬菜土壤中的利用率、残留率和回收率随化学氮肥用量的增加而下降，损失率随化学氮肥用量的增加而增加。合理的化学氮肥用量既提高了化学氮肥的利用率，又降低了化学氮肥的损失率。4．在保证蔬菜高产、优质、低污染的前提下，权衡化学氮肥用量与蔬菜产量、品质和氮肥利用率之间的关系，四种蔬菜合理的化学氮肥用量为，蕹菜：0.1400～0.1700 gN／kg土；莴苣；0.1750～0.2125 gN／kg土；小白菜：0.1750～0.2125 gN／kg土；萝卜；0.1260～0.1530 gN／kg土。5．有机-无机复混肥能提高莴苣和小白菜中、后期功能叶中的叶绿素含量和净光合速率。与纯化肥处理和农民习惯施肥法处理相比，有机-无机复混肥能明显提高莴苣和小白菜中、后期功能叶中的蔗糖磷酸合成酶、蔗糖合成酶和硝酸还原酶的活性。6．有机-无机复混肥能较好的促进莴苣和小白菜的生长，提高莴苣和小白菜的产量和品质。有机-无机复混肥处理莴苣和小白菜产量与农民习惯施肥法处理之间的差异不显著，但与纯化肥处理之间的差异均达极显著水平。有机-无机复混肥能明显提高莴苣和小白菜可食部分的Vc、可溶性糖含量，降低其硝酸盐和亚硝酸盐的累积，维持粗纤维含量在适宜水平，明显地改善了蔬菜的营养与卫生品质。有机-无机复混肥处理莴苣和小白菜的纯收益和产投比最高，极大地提高了蔬菜生产的经济效益。7．与纯化肥处理和农民习惯施肥法处理相比，有机-无机复混肥处理能提高莴苣可食部分的蛋白质含量，但对莴苣可食部分的天冬氨酸、苯丙氨酸、异亮氨酸、酪氨酸含量没有明显的影响。小白菜可食部分中的全氮、蛋白氮含量均以农民习惯施肥处理最高，有机-无机复混肥处理次之，纯化肥处理最低。有机-无机复混肥处理小白菜可食部分中的天冬氨酸、丙氨酸和异亮氨酸含量最高，但与纯化肥处理和农民习惯施肥法处理之间的差异不显著。更多还原

【Abstract】 In order to develop and popularize organic-inorganic compound fertilizer for vegetablecrops, the effects of chemical nitrogen fertilizer application rate on yield and quality （nitratecontent, protein content, soluble sugar content, rough fiber content and Vitamin C content） of 4vegetables（Water spinach, Asparagus lettuce, Pak-choi, Radish）and nitrogen fertilizerutilization ration have been studied by pot experiment using ¹⁵N trace technique. Underguaranteeing the vegetables high yield, and good quality and low pollution, the rationalchemical nitrogen application rate of 4 vegetables have been obtained. And the effects oforganic-inorganic compound fertilizer on the photosynthetic characteristic, key enzymeactivities （such as sucrose synthase, sucrose phosphate synthase and nitrate reductase） ofcarbon-nitrogen metabolism, yields and quality （such as the content of vitamin C, soluble sugar,nitrate, inferior nitrate, coarse fibred and amino acids） of lettuce and Pak-choi are studied byfield plot experiment on the basis of this research conclusion. The results are shown as follows:1. There is a significant correlation between vegetables yield y （kg/pot） and nitrogenfertilizer application rate x （kg urea/pot）; the parabola model regression equation could beexpressed as:Water spinach, FW:（?）=-14816x²+85.496x+0.0149;Asparagus lettuce, FW:（?）=-25951x²+175.23x+0.1042;Brassica chinensis, FW:（?）=-16647x²+113.93x+0.0133;Pak-choi, FW:（?）=-41666x²+225.75x+0.0311.2. The yield of 4 vegetables will increase with the increasing of chemical nitrogenapplication rate, but if the chemical nitrogen application rate is exceeded, the yield of fourvegetables will decrease. Rational chemical nitrogen application rate could increase the yieldof the vegetables.3. Increasing the application rate of chemical nitrogen fertilizer could increase Vitamin Ccontent of the esculent part of four vegetables during certain chemical nitrogen application rate range; but increasing the nitrogen application rate would decrease Vitamin C content ofvegetables after exceeding certain nitrogen application rate. Rational chemical nitrogenapplication rate could promote the synthesis and accumulation of vegetables protein, increasethe content of soluble sugar of vegetables, and chlorophyll content in functional leaves ofvegetables, lengthen the function period of the vegetables function leaves, strengthen theactivities of vegetables, reduce the accumulation of the vegetables nitrate, increase inherentquality and mouth feel of the esculent part of vegetables.4. With the increasing of chemical nitrogen application rate, total nitrogen absorption and¹⁵N% of vegetables plant are increased. Rational chemical nitrogen application rate couldsignificantly improve the absorption from chemical nitrogen and from soil nitrogen. Thechemical nitrogen utilization ratio, residual ratio and recovery ratio in the vegetables soil woulddecrease with the increasing of chemical nitrogen application rate, while the loss rate willincrease. Rational chemical nitrogen rate could improve the utilization ratio of the chemicalnitrogen, and reduce the loss ratio of the chemical nitrogen.5. Under guaranteeing the vegetables high yield, good quality and low pollution, therational chemical nitrogen application rate of four kinds of vegetables is as follows:Water spinach: 0.1400～0.1700 gN/kg soil; Lettuce: 0.1750～0.2125 gN/kg soil;Pak-choi: 0.1750～0.2125 gN/kg soil; Radish: 0.1260～0.1530 gN/kg soil.6. Organic-inorganic compound fertilizer could increase the content of chlorophyll and netphotosynthetic rate in the function leaves during middle and late growth stages of lettuce andPak-choi. Organic-inorganic compound fertilizer could significantly enhance the activities ofsucrose synthase（SS）, sucrose phosphate synthase（SPS） and nitrate reductase（NR） in thefunction leaves during middle and late growth stages of lettuce and Pak-choi as compared tothe treatments of chemical fertilizer and farmer fertilization practice.7. Organic-inorganic compound fertilizer could promote the growth of vegetables, andthus increase the yields and quality of lettuce and Pak-choi. There is not a significant differencefor the yield of lettuce and Pak-choi between the treatments with organic-inorganic compoundfertilizer and farmer fertilization practice; while there are significant differences at 1% levelbetween the treatments with organic-inorganic compound fertilizer and chemical fertilizer. Andorganic-inorganic compound fertilizer could significantly increase the content of Vc and soluble sugar, and decrease the accumulation of nitrate and inferior nitrate and remain adequatecoarse fibre content in esculent part of lettuce and Pak-choi. It could obviously promotenutrient and health quality of vegetable crops. Net incomes and output/input ratio from thetreatment of organic-inorganic compound fertilizer was the highest among three treatments.Organic-inorganic compound fertilizer could significantly increase economic profit ofvegetables production.8. Protein content in esculent part of lettuce with organic-inorganic compound fertilizerwill be increased as compared to the treatments with chemical fertilizer and farmer fertilizationpractice; but there isn’t a significant effect on aspartic acid, phenylalanine, isoleucine andtyrosine. The content of total nitrogen and protein nitrogen in esculent part of Pak-choi fromthe treatment with farmer fertilization practice is the highest among these three treatments; thefollowing is the treatment with organic-inorganic compound fertilizer; the lowest is thetreatment with chemical fertilizer. The content of aspartic acid, alanine and isoleucine of thetreatment with organic-inorganic compound fertilizer is the highest in esculent part of Pak-choi;while there is not a significant difference between these three treatments.更多还原