Cobalt Content In Calcareous Soil And The Effect Of Cobalt On Yield And Grain Quality Of Winter Wheat

Pot and field experiments were conducted to study the effect of cobalt on the growth, physiological, yield and grain quality of winter wheat by the design method of complete random block. The main results were summarized as follows:1. According to the analysis results of 34 soil samples taken from YunCheng, the content of total cobalt range from 1.65 mg·kg^-1 to 17.85 mg·kg^-1, with an average of 6.00 mg·kg^-1, and the available Co content range from 0.060 mg·kg^-1 to 2.235 mg·kg^-1, with an average of 0.694mg·kg^-12. Lower (1² mg·kg^-1) concentration of cobalt enhanced the growth of winter wheat, and higher (4⁸ mg·kg^-1) concentration inhibited growth.3. All Cobalt treatments caused increases of the chlorophyll content, the root activity and NR activity compared with controls in pot and field experiments.4. Cobalt application increased wheat yield compared with controls in pot and field experiments, and the greatest enhances were 4 mg Co/kg soil (pot) and 1.05kg Co/ hm² (field).5. Increasing cobalt application from 1 to 2 mg·kg^-1 improved crude protein content from 4.78% to 9.30% compared with controls, whereas higher (over 4⁸ mg·kg^-1) addition of Co resulted lower crude protein content in the pot experiment.Lower (0.45⁰.75kg·hm^-2) concentration of cobalt produced higher grain quality(crude protein content, sedimentation value, wet gluten content, dry gluten content and valorimeter value) than controls, whereas higher (over 1.35kg·hm^-2) addition of Co resulted in poor seed quality in the field experiment.6. Co content in wheat grain and DPTA-extractable cobalt in soil showed significantly positive correlation with soil-applied cobalt in pot and field experiments. Co content in different parts of wheat decreased in order of leaf>glume>stem>grain, and Co in roots were significantly richer than aerial part..