The studies were conducted in the third year of two field experiments, in which waste such as: slops, straw, sawdust, sugar factory lime and farmyard manure were applied. Waste was applied once in the first year. The hull-less oats, yellow lupine, as a green fertilizer, and potatoes were the forecrop for winter wheat in the first experiment. The chickling vetch and potatoes were the forecrop in the second experiment. In grain and straw samples the content of total and specific protein was determined. Based on the wheat yield (grain and straw) and both protein forms content in it, the protein yield was calculated. It was found that the secondary effect of waste influenced the total protein content stronger than the kind of forecrop and the specific protein content in a smaller degree. All applied waste influenced, in a secondary way, a higher total and specific protein yield. Yellow lupine, used as a fertilizer for winter wheat forecrop had a more positive effect, than chickling vetch straw, the yield of both protein forms.