The Influence of Compost Tea on Plant Growth Performance in Corn and Winter Wheat

Abstract

Nitrogen (N) fertilizer is one of the most important inputs in modern grain production. Without N many crops, including corn (Zea mays L.) and winter wheat (Triticum aestivum L.), would lack one of the most vital nutrients used to produce proteins, amino acids, and chlorophyll. Rising fertilizer costs and increasing interest in sustainable nutrient management practices have prompted research into alternative products that may improve N use efficiency (NUE) while maintaining crop grain yield. Compost tea (CT), a liquid extract produced from composted organic materials, has been widely used in organic vegetable production systems and home gardening applications. The reported potential benefits of CT include increased soil microbial activity, enhanced nutrient cycling, and improved plant health. Limited research has evaluated the effectiveness of CT in intensive row crop production. This study investigated the effects of CT application in combination with varying N fertilizer rates on the growth, physiological status, and grain yield of winter wheat and corn under Virginia growing conditions. Field experiments were conducted during the 2024-2025 growing season at Blacksburg, Orange, and Blackstone, Virginia, using a nested randomized complete block design. Treatments included 100% recommended N with and without CT, 75% recommended N with and without CT, and 50% recommended N without CT. Nitrogen was supplied as split applications of urea ammonium nitrate, and CT was applied once at 5 gal ac⁻¹. Plant height, chlorophyll content (SPAD), and grain yield were measured. Compost tea did not significantly affect plant height, SPAD readings, or grain yield in either crop. Location significantly influenced plant height and grain yield, while SPAD readings were generally similar across treatments and locations. These results indicate that environmental conditions and soil characteristics were the primary determinants of crop performance. Under the conditions evaluated, CT provided no measurable agronomic benefit when combined with conventional N fertilizer programs. Additional multi-year research is needed to determine whether CT may improve crop performance or N use efficiency under specific production conditions.