Critical nutrient concentrations and DRIS analysis of leaf and grain from high‐yielding corn

Abstract

Abstract A field experiment was conducted to optimize fertilizer inputs for maximizing the yield of irrigated com (Zea mays L.). This report is a summary of the nutrient composition of leaf and grain samples from the highest yielding treatment in the experiment. The experiment had 15 treatments replicated three times in a randomized complete block design. The N rate treatments were 45,100, 200, 300, and 400 kg N/ha with and without 50 kg P/ha, 67 kg K/ha, and 22 kg S/ha. The plant populations were 74,000 plants/ha (30,000 plants/A) and 100,000 plants/ha. The highest corn yield was 15.6 Mg/ha (250 bu/A with 15.5% moisture) which was produced with 300 kg N/ha combined with complete N, P, K, and S fertilization. It is assumed that samples of corn leaf and grain from a plot yielding that high would have nutrient concentrations in the sufficiency range. Many of the nutrient concentrations from these arbitrarily designated sufficiency ranges are close to the critical ranges and concentrations reported in the literature. It can be concluded that established critical concentrations and ranges could be useful for diagnosing high‐yielding corn. Furthermore, the negative DRIS indices for N, P, K, S, and Cu indicate that these nutrients are most likely to be limiting based on the published norms.