Wheat Fertilizer Requirements Wikifarmer Nitrogen on winter wheat The Andersons Wheat Stand Assessment Top dressing on a wheat crop is usually done 3 weeks after emergence. Understanding your soil type will help you determine your application rates. In sandy soil, for example, you could do The 4 Rs of Topdressing Wheat AgWeb PDF) Nitrogen fertilization in top dressing for wheat crop in succession to soybean under a no till system