Mineral element content of potato plants and tubers vs. yields

Linear equations for estimating the amounts of N, P, K, Ca, Mg and S removed from the soil as a function of yield are given for Russet Burbank potatoes. The equations were obtained from chemical analyses of potatoes grown using various ratios and rates of fertilizer, planting dates and harvest dates during 1966 to 1969 in the Columbia Basin of the state of Washington. The percentage mineral element composition of the tubers remained relatively uniform for the different ratios and rates of fertilizer but varied some due to the length of season. The correlation coefficients of chemical composition of the vines with chemical composition of tubers were low as were those relating amount in vines to yield. The correlation coefficients relating amounts of elements in the tubers to yield were 0.9 or greater.