不同氮素供应条件下菜心对部分养分的吸收和硝酸盐的积累

Nitrate accumulation and nutrient absorption in flowering Chinese cabbage under different conditions of nitrogen supplied

采用水培试验,研究了9个菜心(Brassicacampestris)品种在不同氮素供应条件下吸收矿质养分以及与硝酸盐累积的关系.结果表明,当营养液中只含硝态氮源时,菜心对钾、钙和氯的相对吸收量与硝酸盐累积量呈负相关关系;当营养液中硝铵态氮的比例为7∶3时,对磷、钾、钙、镁、硫、氯、钼的相对吸收量均与硝酸盐累积呈负相关关系.进一步的分析表明,在这种氮素营养条件下,磷主要是通过改变它与全氮的吸收比例而影响硝酸盐的累积,而其它元素则主要是改变了它们与硝态氮的吸收比例而影响了硝酸盐的累积.

Solution culture experiment was conducted for studying the relation of mineral nutrition absorption and nitrate accumulation in flowering Chinese cabbage under different conditions of nitrogen supplied. It was found that the absorption of K, Ca and Cl was the main influence factor to nitrate accumulation when only NO-3N was supplied in the nutrient solution. When the ratio of NO-3N to NH+4N was 7∶3 in the nutrient solution, the absorption of P, K, Ca, Mg, S, Cl, Mo all influenced nitrate accumulation of flowering Chinese cabbage, and the changes of the ratios of K, Ca, Mg, S, Cl, Mo to NO-3N and P to total N were the main reason in this nitrogen nutrition condition.