Premium
Phytase Supplementation and Reduced‐Phosphorus Turkey Diets Reduce Phosphorus Loss in Runoff following Litter Application
Author(s) -
Maguire R. O.,
Sims J. T.,
Applegate T. J.
Publication year - 2005
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2005.0359a
Subject(s) - phytase , phosphorus , surface runoff , litter , poultry litter , zoology , manure , soil water , chemistry , agronomy , manure management , nutrient , biology , ecology , organic chemistry
Concerns about regional surpluses of manure phosphorus (P) leading to increased P losses in runoff have led to interest in diet modification to reduce P concentrations in diets. The objectives of this study were to investigate how dietary P amendment affected P concentrations in litters and P losses in runoff following land application. We grew two flocks of turkeys on the same bed of litter using diets with two levels of non‐phytate phosphorus (NPP), with and without phytase. The litters were incorporated into three soils in runoff boxes at a plant‐available nitrogen (PAN) rate of 168 kg PAN/ha, with runoff generated on Days 1 and 7 under simulated rainfall and analyzed for dissolved reactive phosphorus (DRP) and total P. Litters were analyzed for water‐soluble phosphorus (WSP) and total P, while soils in the runoff boxes were analyzed for WSP and Mehlich‐3 phosphorus (M3‐P). Formulating diets with lower NPP and phytase both decreased litter total P. Phytase had no significant effect on litter WSP at a 1:200 litter to water extraction ratio, but decreased WSP at a 1:10 extraction ratio. Using a combination of reducing NPP fed and phytase decreased the total P application rate by up to 38% and the P in surplus of crop removal by approximately 48%. Reducing the NPP fed reduced DRP in runoff from litter‐amended soils at Day 1, while phytase had no effect on DRP concentrations. Increase in soil M3‐P was dependent on total P applied, irrespective of diet. Reducing overfeeding of NPP and utilizing phytase in diets for turkeys should decrease the buildup of P in soils in areas of intensive poultry production, without increasing short‐term concerns about dissolved P losses.