Abstract:

To explore the potential of fertilizer reduction and efficiency improvement, and provide data support for the safe and efficient production of facility celery, a field experiment was conducted with celery ‘Ventura’ as experimental material. Four treatments were set up: conventional fertilization (4.5 t/hm² bio-organic fertilizer+375 kg/hm² chemical fertilizer), T1 (50% reduction of bio-organic fertilizer+15% reduction of chemical fertilizer), T2 (50% reduction of bio-organic fertilizer+30% reduction of chemical fertilizer), T3 (no bio-organic fertilizer+30% reduction of chemical fertilizer). The plant height, yield, quality and nutrient accumulation of celery and soil physical and chemical properties were measured. The results are as follows. (1) Compared with conventional fertilization, T1 and T2 did not reduce the yield of celery. The yield of T1 was the highest, which increased by 17.90%, and the plant height of T1 was relatively high. The yield of T3 decreased. (2) Chemical fertilizer reduction combined with application of bio-organic fertilizer increased fertilizer partial productivity, and T2 had the largest increase. (3) Chemical fertilizer reduction combined with application of bio-organic fertilizer could significantly reduce the nitrate content and increase the crude fiber content of celery. The quality of celery in T1 was better than that in conventional fertilization treatment. (4) Compared with the conventional fertilization, T1 and T2 reduced soil pH and increased the contents of alkali-hydrolyzable nitrogen and available potassium, and T2 had significant differences. The nutrient accumulation of celery organs with bio-organic fertilizer application was higher than that without bio-organic fertilizer application, and the nutrient accumulation of celery organs showed an increasing trend with the decrease of chemical fertilizer application. Comprehensively considering celery yield, fertilizer partial productivity, celery quality and soil properties, under the condition of facility celery planting, the reduction of chemical fertilizer combined with application of bio-organic fertilizer is a safe and efficient way of fertilization. Under the condition of this study, the optimal amount is bio-organic fertilizer 2.25 t/hm² (50% reduction of bio-organic fertilizer)+ chemical fertilizer 318.75 kg/hm² (15% reduction of chemical fertilizer). However, the effects of chemical fertilizer reduction combined with application of bio-organic fertilizer on long-term yield of celery and soil nutrients need further verification.

Key words: chemical fertilizer reduction, bio-organic fertilizer, yield, quality, soil physical and chemical properties