Optimizing Corn and White Clover Competition in the Living Mulch System.

Using a living mulch (LM) system to produce row crops attempts to perpetuate perennial legumes over years while growing in binary cultures with row crops.  Shading forces the legume to drop its leaves which provides N to the row crop, but excessive shading and leaf loss compromises the health of the legume.  A study was conducted to examine the impacts of row spacing, herbicide banding, and corn population density on white clover yield and perenniation.  White clover was established in Floyd Co. and Watkinsville, GA.  Herbicides were applied in either 20 or 40 cm bands sprayed on either 75 or 90 cm centers.  Corn was planted into the dead bands of clover at high- and low- population densities.  In summer, corn height, clover mass, % shading, and grain yield were measured in 2014 and 2015.  In addition, clover re-establishment was determined by measuring basal cover every 28 days after corn harvest until planting the following year.   Clover shading was more pronounced in plots planted on 75-cm rows, and plots planted to 90-cm rows had greatest yields at both locations and years.  Herbicide bands of 40-cm had greater yields in 2014, but lower yields in 2015 because of a detrimental effect on post-harvest clover re-growth.  The living mulch production system remains a promising option for growing row-crops, but challenges remain to be resolved prior to providing a reliable system for producers.