Abstract
A study was made of the effects of different quantities of fertilizers (N, P, and K-manure) upon protein content of wheat grains when the plants were grown under a condition with warmer winter and rainy spring. The results obtained were as follows ; (1) Among three essential elements of fertilizers, nitrogen had considerable influence upon percentage of protein in wheat grains ; a series of N-manuring experiment ranging from none to 150 pounds per acre in the form of sulfate of ammonia revealed that protein content of grains from the plot without N-manure showed the highest and that of grains was at first decreased with the increase of the quantities of N-manure to some extent, but it was gradually increased with the application of an excess of N-manure. (2) Phosphorous manure had slight effects on the N-content ot grains and there was found a declination that the increase of P-manure resulted the decrease of the protein content of grains. (3) Potassium had almost no effect on the protein content. (4) It was known in this experiments that a large yield of high protein wheat can be secured by the sufficient supply of available nitrogen for the wheat plant during the whole growing period.
