过氧化脲及尿素配比对水培上海青生长及品质的影响

水培蔬菜中硝酸盐富集及供氧状况是当前水培体系亟待解决的问题.为降低水培上海青Brassica campestris ssp.Chinensis(L.)硝酸盐含量,本研究分别通过部分尿素替代日本园试配方中硝酸盐,以及不同过氧化脲(UHP)与尿素配比的方式,探究减硝增氧对水培叶菜生长及品质的影响.首先以30％、40％、50...

Effects of Urea Hydrogen Peroxide and Urea Ratios on Growth of Brassica Campestris in Hydroponic Culture

Nitrate enrichment and oxygen supply in hydroponic vegetables are urgent problems that need to be solved in the current hydroponic system. In order to reduce the nitrate content of Brassica campestris ssp. Chinensis (L.) in hydroponic culture, firstly, we used partial urea replacing nitrate in the Japanese garden test nutrition solution, and then explore different urea-hydrogen peroxide (UHP) and urea ratios to study the effects of nitrate reduction and increment oxygen on the growth and quality of B. campestris in hydroponic. First of all, 30%, 40%, 50%, 100% urea was used to replace nitrate to optimize the Japanese garden test nutrition solution. Compared to the control treatment, 50% urea substitution treatment significantly increased the yield and had a significant effect on root growth of B. campestris. Furthermore, 10%, 30%, 50% and 80% UHP used to replace partial urea in the modified Japanese garden test nutrition solution, so as to determine the best ratio of UHP to urea and nitrate. With increase of UHP concentration, the dissolved oxygen concentration in the nutrient solution increased significantly, increased by 7.63%-39.7% compared with the control. Moreover, 30% UHP treatment increased 27.65% compared with control treatment, as well as the total root length, root surface area, average root diameter, root volume and root tip number respectively increased by 24.68%, 36.92%, 16.9 %, 28.19% and 28.89% than control treatment. However, the growth of B. campestris significantly inhibited in 50% and 80% of UHP treatments. Chlorophyll and VC contents in 30% UHP treatment were significantly increased by 71.25% and 34.91, respectively, than control treatment. With increase of UHP concentration, the nitrate content of leaves showed a downward trend. Nitrate contents in 10%, 30%, 50% and 80% UHP treatments significantly decreased by 3.86%, 9.69%, 22.71%, and 26.87%, respectively, compared with the control treatment. It was concluded that appropriate nitrate reduction and increment of oxygen could stimulate root development, improve yield and quality of B. campestris. The optimized ratio of nitrogen content in UHP: urea: nitrate was 3:7:10.