Accretion and Dilution of Nutrients in Young Corn, as Affected by Yield Response to Nitrogen, Phosphorus, and Potassium

Abstract

Abstract Hybrid corn ( Zea mays L.) was grown in infertile soil fertilized with none and three nonzero rates of N, P, or K in separate treatment series; other nutrients were applied in each series at uniform levels. Near‐linear increases in uptake of N, P, or K with amount applied occurred during 25, 41, and 53 days' growth. Concentrations of N, P, or K increased with amount applied and decreased with continued growth in each series; uniformly applied P and K, N and K, or N and P were diluted with increase in dry matter resulting from continued growth and yield response to increasing amounts of the third nutrient. Yield‐concentration relationships in the N response series were similar for N, Ca, Mg, Mn, and Zn. Response to P or K resulted in dilution of all other nutrients. Concentrations of total cations increased with concentrations of N in each response series; the reverse was true with P and K. Thus, the results suggest that a positive relationship between dry matter yields and total cations ( C ), total inorganic anions ( A ), and C‐A depends on whether yield response is due to N or to other growth‐limiting factors.