Mineral fertilizers and green mulch in chinese cabbage [Brassica pekinensis (Lour.) Rupr.]: Effect on nutrient uptake, yield and internal tipburn

摘要

Large applications of mineral fertilizers in Chinese cabbage [Brassica pekinensis (Lour.) Rupr.] increased growth, total nitrogen and nitrate concentrations at harvest, and increased the occurrence of internal tipburn. Green mulch, as the only fertilizer or in combination with small amounts of mineral fertilizers, resulted in slower growth and lower total nitrogen and nitrate concentrations at harvest, and also prevented the occurrence of internal tipburn. No visible symptoms of nutrient deficiencies were detected, but plant analyses showed that the concentrations of magnesium, zinc, manganese and copper were below the estimated sufficiency limits in all fertilizer regimes. High soil pH, 6.4-6.8, and large amounts of calcium in the soil decreased the availability of these elements. The results demonstrate the importance of simultaneous analyses of several elements in revealing suboptimal concentrations and/or imbalances that depress yield and quality but do not result in visible symptoms. The results also indicate that organic fertilizers such as green mulch may be more suitable than mineral fertilizers in preventing the occurrence of physiological disorders such as tipburn.