Critical N, P and K levels in winter wheat

Publisher Website
Google Scholar
Abstract
The NO3‐N content of wheat samples collected in December and January did not increase with increasing rates of nitrogen, therefore no critical NO3‐N level could be established for these periods. The critical NO3‐N content of samples collected at the “joint”; stage of growth was 350 ppm. Phosphorus concentration in the forage did not vary greatly during the growing season, therefore only one critical level for phosphorus appeared necessary. The critical level of phosphorus for all sampling dates was 0.45 percent. Critical K levels had to be established for each stage of growth because differences in K concentrations at the various growth stages were greater than differences caused by K fertilization. It was also observed that P deficient plants tended to accumulate NO3‐N much more than plants adequately supplied with P.