Nutrient Concentration Changes in Corn as Affected by Dry Matter Accumulation with Age and Response to Applied Nutrients
1973
Terman, G. L. | Noggle, J C
Hybrid corn (Zea mays L.) was sampled each week on field plots of soil testing adequate in P and K at Muscle Shoals, Alabama, in 1972, to relate plant analyses results to growth and maturity. Treatments of N compared were no N, 28 kg/ha at planting + 84 kg/ha topdressed at tasseling, 56 kg/ha at planting, and 112 kg/ha at planting. Plots of cumulative yields vs nutrient concentrations were used to evaluate the results. Corn yields increased markedly with amount of applied N, but single and split applications of N resulted in similar yields. Concentrations of N in the top leaves, ears, and entire topgrowth also increased at each harvest date with amount of applied N. Applied N also resulted in higher concentrations of P, Ca, and Mg, but lower K concentrations in the top leaves at most sampling dates. At each rate of applied N, concentrations of N in leaves, ears, and entire tops decreased with maturity. Concentrations of P remained about the same; Ca and Mg first decreased and then increased to maturity, whereas the opposite trends resulted for K concentrations. These opposite trends in results from this experiment and from other studies illustrate the strong reciprocal relationship between concentrations of K and Ca + Mg in plants. Nutrient concentration trends with increasing yields and age of plant are influenced in general by amounts of available nutrients and various growth-limiting factors.
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