Effect of Ammonium and Nitrate Ratios on Growth and Yield of Flowering Chinese Cabbage

The effect of different ammonium and nitrate ratios (NH4+-N : NO3--N = 0:100, 25:75, 50:50 and 75:25) on growth and yield of flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee) with 3 cultivars were studied in hydroponics. The results indicated that, compared with the complete nitrate treatment, plant height, stem diameter and biomass of flowering Chinese cabbage were increased in the low enhancement of ammonium (25%) in nutrient solution, while plant growth and biomass were decreased in the medium (50%) and high (75%) enhancement of ammonium. Compared with the complete nitrate treatment, low enhancement of ammonium (25%) in nutrient solution increased root activity of flowering Chinese cabbage, while it was decreased by the medium (50%) and high (75%) enhancement of ammonium treatments. Nutrient solution with 25% ammonium enhancement maintained a high root absorption capacity and increased plant biomass, so it was appropriate to hydroponics for flowering Chinese cabbage.