Effects of Topsoil-subsoil Fertilizer and Lime Amendments on Top and Root Growth of ‘Stuart’ Pecan Seedlings in a Simulated Norfolk Soil Profile1

Abstract

Abstract Fertilizer and lime topsoil treatments increased top and root growth of open-pollinated seedlings of ‘Stuart’ pecan [Carya illinoensis (Wang.) K. Koch] under simulated Norfolk profile conditions in the greenhouse. Positive response was greatest on root growth when lime was added to the subsoil. Rate of tap root growth in the subsoil was increased 64% by increasing subsoil pH from 5.1 to 6.5. Lime additions to the subsoil reduced weights of lateral roots in the topsoil and increased yields in the subsoil. Subsoil lime at 2 and 3 meq Ca/100 g soil (pH 6.0 and 6.5) increased yields of the small feeder roots 3 and 6 fold over the untreated check (subsoil pH 5.1). Acid subsoils can be an important factor limiting growth of pecan roots under soil conditions prevalent in much of the Southeast.