Contribution of soil and crop parameters on sudangrass productivity based on farm survey

Despite an increase in sudangrass cultivation, fertilization is still dependent on farmers experience due to the absence of standard fertilization recipe. The objective of this study is to investigate the influence of soil and crop parameters on sudangrass productivity, and to suggest the necessity of standard fertilization guideline. For this purpose, we conducted a survey on fertilization at 24 sudangrass farms in the Chungbuk province and analyzed soil chemical properties and sudangrass yield. Exchangeable K, Ca and Mg affected the yield of sudangrass, and especially Ca/K and Mg/K were closely associated with yield. In terms of nitrogen supply, excessive nitrogen application resulted in an adverse effect on yield. Fertilization was negatively correlated with nitrogen recovery and nitrogen use efficiency, and positive correlation was evident between soil chemical properties or between crop parameters. These findings imply that an adjustment of fertilization including compost and soil chemical properties ensure favorable sudangrass production, and this study suggests the necessity of standard and/or soil-testing fertilization guideline with further work.Nitrogen fertilization rates and nitrogen use efficiency by yield of sudangrass. ○ = High potential outlier. * = High extreme values.