不同施氮水平对滨海盐土上油葵产量与品质的影响

Influence of nitrogen on yield and quality of sunflower growing in coastal saline soil

田间小区试验的研究结果表明:(1)施用氮肥对油葵(G101-B)有明显的增产效应。油葵产量随施氮量的增加而提高,当施尿素N105kg/hm2时,强度与轻度盐渍化土壤上的油葵均获得了高产;但进一步增加氮肥,会导致减产;(2)施用氮肥增强了油葵的耐盐性。施用氮肥能减少油葵对Na+、Cl-的吸收,降低Na+、Cl-的毒害;还能增强油葵对K+的选择性吸收和运输,提高了油葵的SRK,Na值和K+含量;(3)氮、磷肥存在显著的正交互作用;(4)施用氮肥能促进葵籽内的蛋白质与脂肪合成,但氮肥过量会降低脂肪含量而影响葵籽品质。

Field experiments revealed that nitrogen application led to significant differences in the yield and quality of sunflower (G101B). Seed yield, 1000seed weight and the contents of protein in seed increased with the increment of N application while total lipid in seed increased at the lower rates of N application but decreased at higher rates. More nitrogen would reduce the content of lipid, which would cause the poor quality of sunflower seed. The highest yields of sunflower seeds were obtained in the application of N105kg /hm2 in both low (0.12～0.15%) and high (0.28～0.35%) salt contents, but more nitrogen made the yield decrease. Meanwhile, there were significant interactions on seed yield between nitrogen and phosphorous. Results also indicated that nitrogen application could promote sunflower's intake and transportation of K+ and prevent sunflower from absorbing more Na+ and Cl-, which would raise the value of SRK,Na and decrease the harm of salt to sunflower. It could be inferred that proper application of N fertilizer might be useful in better utilization of saline soil by plants.