A corn producer irrigates three times each season with 2 in. irrigation H2O. The H2O analysis report show 2 ppm S. The total above-ground biomass (grain plus residue) weighs 4 t/a (2.5% N, 12:1 N:S). The soil contains 2% OM (8:1 N:S), which degrades at 1% per year. Calculate the additional S needed by the crop (lb S/a). (hint: density of H2O = 1 g/cm3 or (using unit conversions) 62.4 lb H2O/ft3; how many ft3 H2O/a are applied?)
I have calculated amount of S in biomass - 1.7 lbs S/a and from OM - 2.5 lbs S/a mineralized. Need help on calculating pounds of S from irrigation
