Cover Crop Management Effects on Soil Physical and Biological Properties

Abstract

Cover crops have been known to reduce soil erosion, among other benefits, and increase water infiltration, organic matter and soil microbial activity. This study was conducted at Lincoln University's Freeman farm during 2011 and 2012 to assess the effects of cover crop management on soil physical and biological properties. The soil of the experimental site was a Waldron silt loam soil (Fine, smectitic, calcareous, mesic Aeric Fluvaquents). The field was 4.05ha in size and subdivided into 48 plots, each measuring 12.2 m x 21.3 m. The cropping pattern for the plots was a corn (Zea mays L.)/soybean (Glycine max) rotation. The cover crop of choice was cereal rye (Secale cereale). Half of the total plots had cover crop management while the other half had no-cover crop. Soil samples were collected at four depths; 0-10, 10-20, 20-40 and 40-60cm. Samples were oven dried at 105oC for 72h for soil physical properties analysis. Air dried soil samples were also sent to a commercial laboratory for analysis of soil biological properties. Results showed a significant effect (p< 0.05) of cover crop on the selected soil physical and biological properties. A 3.5% decrease was also observed in soil bulk density in cover crop plots as compared with no-cover crop plots. The carbon to nitrogen (C/N) ratio decreased with increasing sampling depth for the first three depths and increased slightly in the fourth depth (p<0.05). C/N ratio also showed a 5.6% increase in no-cover crop plots as compared with cover crop plots. The cover crop used in this study was capable of significantly improving soil physical and biological properties.