Combined Poultry Litter and Cover Crop Effects on Corn Productivity, N Cycling, and Soil Quality and Health Indicators.

A more thorough understanding of the effects of integrating cover crops and poultry litter in a strip till corn production system on crop productivity, N cycling, and soil quality and health is needed to improve sustainable management of resources. The objective of this research was to determine how cover cropping and fall applied poultry litter contribute to strip till corn productivity, N cycling, and changes in soil quality and health indicators. Cover crop treatments included winter fallow, a legume, rye (Secale cereale L.), and a bi-culture of a legume plus rye all with and without 2000 kg/ha (d.w. basis) of fall applied poultry litter. Corn response to fertilizer N rates (0, 56, 112, 168, and 224 kg N/ha) was used as a standard comparison to cover crop X poultry litter treatments. Cover crop N content at termination averaged across 5-y and poultry litter treatments was 65, 36, and 57 kg N/ha for legume, rye, and the legume rye bi-culture, respectively. Poultry litter increased cover crop N content by 12 kg N/ha averaged across 5-y. Grain yield increased year to year from 2013-2015 for all cover crop treatments, except the bi-culture without poultry litter declined in 2014, but increased in 2015. The 0 and 56 kg N/ha fertilizer treatments also increased in grain yield from 2013-2015, while all N rates of 112 kg N/ha and greater showed a declining trend in year to year yield. All treatments experienced a decline from the previous year in 2016 due to low rainfall. Following 4-y of treatments, only cover crops which included poultry litter showed signs of reducing bulk density. Cover crop treatments which included a legume resulted in increasing soil total C and N with and without poultry litter. Soil enzymatic activity for the fourth year corn planting measured using fluorescein dye hydrolysis indicated increased activity with all cover crop treatments, but the greatest activity was found with all combinations of a legume plus poultry litter. The greatest overall indication of increased crop productivity and improved soil quality and health indicators was found with a legume cover crop and generally poultry litter combined with a legume resulted in the greatest changes.