生物肥部分替代化肥对花椰菜产量、品质、光合特性及肥料利用率的影响

高原夏季蔬菜生产面临着化肥过量使用导致的蔬菜品质下降、肥料利用率低和地下水污染等问题,通过研究生物肥部分替代化肥,探讨生物肥的增效作用、替代量和肥料利用率,为菜田合理施肥与提高蔬菜品质提供科学依据。采用随机区组试验,设不施肥(CK)、100%常规施肥(100CF)、80%常规施肥(80CF)、60%常规施肥(60CF)、100%常规施肥+生物肥(100CFB)、80%常规施肥+生物肥(80CFB)、60%常规施肥+生物肥(60CFB)7个处理,研究了化肥配施生物肥对花椰菜产量、品质、养分分配、肥料利用率及光合特性的影响。结果表明,与单施化肥相比,配施生物肥可显著提高花椰菜花球单重,同时提高了氮、磷、钾肥利用率及其吸收量;与100%常规施肥相比,化肥减施20%配施生物肥提高了花球产量,而化肥减施40%配施生物肥显著降低了花球产量,化肥减量配施生物肥显著降低了花球硝酸盐含量,显著提高了花球维生素C和可溶性糖含量;以80CFB处理氮肥利用率和功能叶吸氮量最高,100CF处理花球吸氮量最高,易造成硝酸盐的积累;配施生物肥增加了叶片净光合速率和气孔导度,减小了叶片胞间CO₂浓度。因此,适当减施化肥配施生物肥(80%常规施肥+生物肥)在不影响花椰菜产量的同时,能够显著改善花椰菜的品质、提高肥料利用率和光合效率。

Effects of partial substitution of mineral fertilizer by bio-fertilizer on yield,quality,photosynthesis and fertilizer utilization rate in broccoli

The over-use of inorganic fertilizer in summer vegetable production leads to diminished vegetable quality, nutrient use inefficiency and groundwater pollution. It is not known whether the combined application of bio-fertilizer with mineral fertilizer can improve quality and yield. A field experiment with broccoli (Brassica oleracea var. botrytis) has been under taken to investigate the effects of different combinations on quality, yield, nitrogen, phosphorus and potassium distribution rates, fertilizer utilization rate and photosynthesis. Three different rates (60%, 80% and 100%) of the conventional doses of nitrogen, phosphorus and potassium fertilizers (CF) were combined with bio-fertilizer (CK) in 6 treatments as follows: 60% CF without bio-fertilizer (60CF), 60% CF with bio-fertilizer (60CFB), 80% CF without bio-fertilizer (80CF), 80% CF with bio-fertilizer (80CFB), 100% CF without bio-fertilizer (100CF) and 100% CF with bio-fertilizer (100CFB). These treatments were applied to the crop in a randomized complete block design with three replicates.The head weight of broccoli with bio-fertilizer treatments significantly increased compared to that of sole mineral fertilizer treatments. The bio-fertilizer treatments’ utilization rates and uptake of nitrogen, phosphorus and potassium were also higher. Compared with 100CF, the yield under 80CFB increased, whereas the yield under 60CFB decreased. Compared with 100CF treatment, the nitrate content in the broccoli head decreased significantly, while the vitamin C and soluble sugar contents significantly increased under lower CF and bio-fertilizer treatments. Nitrogen uptake was highest in the functional leaf of broccoli with 80CFB and in the head of broccoli with 100CF. Under the treatments with bio-fertilizer, the photosynthetic rate and stomatal conductance increased, whereas intercellular CO₂ leaf concentrations reduced. These results demonstrated that the 750 kg/ha bio-fertilizer combined with 80% conventional mineral fertilizer can improve broccoli head quality, fertilizer utilization rate and photosynthesis.