Effects of Biochar and Fertilizer Source on Sweet CornProduction: Nitrogen Uptake, Biomass, Yield, and Quality across Two Contrasting Years Part I

Abstract

Sweet corn(Zea mays convar. Saccharata var. rugosa) is akeycrop in Georgia with high mineral nutrient demands that make soil fertility management essential for sustained productivity. This study evaluated the effects of locally sourced biochar at different application rates (0, 5, 10, 15, and 20 tons/acre) combined with inorganic (granular) or organic (poultry litter) fertilizer on nitrogen uptake, plant growth, yield, and ear quality of sweet corn. Field trials were conducted on sandy loam soil using a 5 3 2 factorial arrangement of treatments in a randomized complete block design with four replications. The results showed that higher biochar rates (15–20 tons/acre) increased nitrogen uptake by 9.5% to 13% when compared with the control, with the greatest uptake observed in 2023 under favorable rainfall conditions. Organic fertilizer improved the total soluble solids (TSS), a key indicator of ear quality, but neither biochar nor fertilizer type significantly affected plant growth, biomass, or yield. Environmental conditions, particularly early-season rainfall, strongly influenced outcomes, with heavy rainfall in 2024 reducing nitrogen uptake and ear quality compared with those in 2023. These findings suggest that biochar can enhance nitrogen retention in coastal plain soils, whereas organic fertilizers may improve ear quality. However, the limited duration of the study highlights the need for long-term research to fully assess the cumulative effects of biochar on soil health and yield stability. Moreover, the findings emphasize that rainfall plays a critical role in influencing the performance of soil amendments, thus underscoring the importance of considering environmental variability in nutrient management strategies. This study provides valuable insights into the use of soil amendments for optimizing sustainable sweet corn production in southern Georgia.