Consequences of pelletized poultry litter applications on soil physical and hydraulic properties in reduced tillage, continuous cotton system

摘要

Keeping soil healthy as a medium that can supply adequate nutrients for plant growth is essential for sustainable agriculture. Large amounts of poultry litter are generated on commercial poultry farms in the southeastern United States. While applying poultry litter generally enhances soil nutrients and crop productivity, few studies have investigated changes in soil physical and hydraulic properties. As part of a larger study on cotton (Gossypium hirsutum L.) response to pelletized poultry litter (PPL), this study investigated soil physical and hydraulic properties in a Marietta fine sandy loam soil at two times, in the fall of 2014 and spring of 2015, after repeatedly applying 6.7 Mg ha(-1) PPL in a precision sub-surface band, 134 kg ha(-1) N (as ammonium nitrate) in subsurface bands and no fertilizer (control) for four years (2010-2013). Soil measurements were made at 0-15 cm depth in three plots of each treatment randomized as a complete block design. As compared to unfertilized plots measured in fall 2014, annual applications of PPL increased soil aggregate stability, plant available water, field capacity, saturated hydraulic conductivity, and infiltration by 10, 52, 26, 80, and 54%, respectively. These same soil properties measured in spring 2015 were greater in PPL than control plots by approximately 16, 28, 18, 90, and 100%, respectively. In fall 2014, soil bulk density and penetration resistance were approximately 6 and 19% lower, respectively, in PPL than unfertilized plots. In fall 2014 and as compared to commercial N fertilizer, annual PPL applications increased soil aggregate stability, plant available water content, field capacity, saturated hydraulic conductivity, and infiltration by 6%, 18%, 11%, 38% and 44%, respectively. These results are useful for development of management practices that improve soil health and function.