Soybean Response to Plant Density and Residual Soil Management

Abstract

ABSTRACT Proximity determines the feasibility of using animal manures in cash crop farming systems. However, sustainable farming practices balance nutrient inputs and outputs to minimize the buildup of potentially deleterious levels of soil nutrients. The objectives of our research were to determine the residual effect of dairy (Bos taurus) manure application to corn (Zea mays L.) on subsequent continuous soybean [Glycine max (L.) Merr.] growth and seed yield at different plant densities under previous soil management regimes. The 3-year study was conducted on a Quakertown silt loam (fine-loamy, mixed, mesic Typic Hapludult) at an upland New Jersey location. Soybean was planted at 371,494, and 618,000 seeds ha−1 and previous soil management treatments applied to corn from 1995–1998 were a control (no sidedress N or manure), sidedress N, manure, and manure plus sidedress N. Light interception, dry matter, and nitrogen accumulation at R1-R2 were poor predictors of seed yield. Seed yield in manure treatments was 48% greater than non-manure treatments in a dry year, the first residual year after manure application, but was similar or minimally greater in the two years with average precipitation. These data provide additional rationale to follow sustainable practices that distribute manure more evenly across landscapes to minimize buildup of excessive levels of soil nutrients.