Split Nitrogen Applications in Wheat
Late January or early February is the ideal time to evaluate your wheat tiller density and apply additional nitrogen. Timely applications of nitrogen will help promote additional tillers if your wheat is small. At this stage, 50 tillers per square foot is optimum. If wheat was planted late, tiller counts may be significantly lower. Use the formula below to determine your tillers per square foot.
Tillers per square foot = Tillers per yard of row X 4 / row width in inches
If tiller density is less than 50 tillers per square foot: Apply ½ of the topdress nitrogen in late January or early February, and the remaining ½ in early-mid March. The first application will enhance tillering on warm days without fostering excessive growth. If tiller density is more than 50 tillers per square foot: Apply all topdress nitrogen in early March.
Applying all the nitrogen in late January/early February could pose problems. The nitrogen would increase tillering, but it would also make the wheat more prone to freeze damage. This traditional practice may also cause late-season nitrogen stress and reduced potential yields.
Splitting the nitrogen stimulates tillering without the increased risks of freeze damage, disease, and lodging. The second application in March would also give the wheat more nitrogen later in the spring when it is necessary for grain production.
How To Count TIllers To Time Spring Nitrogen video: http://www.smallgrains.ncsu.edu/tiller-counting.html