銨氮和硝酸氮對於黃瓜生長的影響

The effect of nitrogen from ammoninm and nitrate on the growth of cucumbers

Cucumbers (Cucumis sativus cv. Pioneer) prefer NO3-N uptake. The different combinations of NH4-N and NO3-N (NH4-N ppm/NO3-N ppm: 75/25, 50/50, 25/75.) did not interfere with NO3-N uptake. However, the existence of NO3-N in a solution with NH4-N did significantly enhance the uptake of NH4-N. The cucumbers grown in NH4-N had fewer leaves, shorter stems, lower fresh and dry weights than those grown at the same level in NO3-N. The cucumbers grown in NO3-N had about the same fresh and dry weights, stem length and leaf number as those grown in the combinations of NH4-N and NO3-N at the same level of nitrogen. The pistillate flower differentiation of cucumbers was not promoted by the nitrogen from ammonium and or from nitrate in the nutrient solutions.