Soil Temperature and Sewage Sludge Effects on Corn Yield and Macronutrient Content

Abstract

AbstractAvailability of plant nutrients and subsequent plant growth are influenced by sewage sludge loading rates and soil temperature, but published information on the interaction of these two factors is limited. Corn (Zea mays L.) was grown in a sandy Typic Hapludult soil amended with 0, 56, or 112 metric tons/ha of anaerobically digested sewage sludge in field experiments during 1975 and 1976. Soil temperature regimes of 16, 27, 35°C or ambient (x̄ = 22°C) were applied to plots each year from planting to harvest. The objective of this research was to evaluate the effect of soil temperature on sewage sludge nutrient release for corn growth.Increases in soil temperature increased germination and maturation rates of corn. A 16°C soil temperature significantly decreased stover and grain yields both years. In 1975, temperatures above ambient did not result in higher grain or stover yields, but in 1976 grain and stover yields increased as soil temperature rose to 35°C.Sewage sludge application had no significant effect on 1975 stover yield, but at a 16°C soil temperature grain yields were significantly higher for the 112‐metric tons/ha sludge plots. In 1976, when pH and soil fertility of check plots had declined, check plots had significantly lower grain yields than sludge‐amended plots at all soil temperatures. Stover yields from 112‐metric tons/ha sludge plots were significantly higher than for check plots at all soil temperatures except 16°C.Nitrogen, P, and K levels in corn ear leaves were higher at 35 than 16°C in both years, but Ca was lower. Higher ear leaf levels of N, P, Ca, and Mg occurred with 112 metric tons/ha sludge than the check in both 1975 and 1976.