To investigate the effect of organic fertilizer type and dosage on the salt tolerance and antioxidant characteristics of winter wheat in salinity fields in the low plain brackish water recharge area of Hebei, in this study, three dosages each of pig manure and sheep manure (low: 9 t·hm-2; medium: 18 t·hm-2; high: 27 t·hm-2) and control and recommended fertilizer applications were set up, with a total of eight treatments. The effects on growth, carbon and nitrogen metabolism, antioxidant characteristics and yield of winter wheat were investigated. The results showed that the number of tillers per plant with high pig manure and sheep manure was increased by 18.42% and 23.68%, respectively, compared with the recommended fertilizer; dry matter accumulation at the booting, flowering and harvest stages was significantly increased by high and medium pig manure and sheep manure treatments, compared with the control and recommended fertilizer application, with an increase rate of 24.54% and 24.60% for the high pig manure and high sheep manure, respectively, and an increase rate of 29.94% and 29.99% at the harvest stage for the high sheep manure. The soluble protein, soluble sugar and free amino acid contents, and SOD and POD activities of post-flowering flag leaf of winter wheat under the high pig manure and sheep manure treatments were significantly increased, and the accumulation of superoxide anion radicals was reduced compared with the control and recommended fertilizers, with sheep manure significantly increasing the soluble sugar content compared with pig manure. High and medium organic fertilizers increased the number of spikes per unit and thousand-grain weight, and the yield increase was significant, with an increase rate of 15.09% and 8.95% for pig manure treatment, and 22.06% and 9.34% for sheep manure, respectively, compared with the control, but there was no significant difference between the two organic fertilizers. In conclusion, for mildly saline soils in the low plain brackish water recharge area of Hebei, it is recommended that high amounts (27 t·hm-2) of pig manure or sheep manure can be applied in wheat production to promote the physiological characteristics of salt tolerance and yield, but overall the effect of sheep manure on increased yield is better than pig manure. |