Grain specific weight is measured in kg/hectolitre, and is an indication of the density of the grain. Many markets require wheat grain to be at a minimum specific weight to be utilized. For example, some millers require a minimum of 76kg/hl, whilst some animal feed producers require a minimum value of 72 kg/hl. Specific weight is predominantly a genetic trait of varieties, but poor crop nutrition and application can reduce specific weight.
Nitrogen used at above optimum levels can cause lodging of a crop which leads to germinating of the grains in the ear, and as a consequence, a lower specific weight.
Variable applications of nitrogen with the optimum rate across the field can be used to create a more homogeneous crop.
Potassium increases the thickness and strength of wheat straw and thereby its resistance to lodging. Spring applications of potassium will ensure a good canopy structure least prone to lodging.