Soil Fertility Studies With Lespedeza Cuneata.

Lespedeza cuneata is a popular, perennial legume forage crop in the southeastern U.S. often called “sericea”.  No published, soil fertility research could be found with this crop.   Two long-term soil fertility experiments on a Hartsells fine sandy loam (fine-loamy, siliceous, thermic Typic Hapludults) in Alabama were seeded to 2 cultivars of sericea in 2004 and monitored for 5 years.  Soil fertility variables include N rates, residual soil P levels, K levels, soil pH, and soil Mg levels.  All treatments produced a mean dry matter yield of 14 Mg ha^-1yr^-1 . Critical Mehlich-1 extractable P and K values for sericea on this soil were identified as 25 mg P kg^-1 and 40 mg K kg^-1, the same value as currently used in the Auburn University Soil Testing program.  Although these data did not allow establishing a critical soil test pH value for sericea, we did observe significant yield decreases when the soil pH was below 5.0.