TITLE:
Nitrogen Fertilization Impacts on Phosphorus Cycling in Grazed Grass-Legume Pasture
AUTHORS:
Sandra L. Dillard, Charles Wesley Wood, Brenda H. Wood, Yucheng Feng, Walter Frank Owsley, Russell B. Muntifering
KEYWORDS:
Feces, Decomposition, Phosphorus Mineralization
JOURNAL NAME:
Agricultural Sciences,
Vol.6 No.9,
September
29,
2015
ABSTRACT: The impact of different N regimes on P intake and excretion by grazing cattle and P return to soil from feces in a P-enriched pasture was investigated. Six 0.28-ha plots were over seeded with triticale (×Triticosecale rimpaui Wittm.) and crimson clover (Trifolium incarnatum) into tall fescue (Lolium arundinacea)/bermudagrass (Cynodon dactylon). Treatments included: 100% of N in split application, 50% of N in single application, and 0% of N. In summer, plots were over seeded with cowpea (Vigna unguiculata) and fertilizer treatments were applied. Forage intake was estimated from fecal excretion and fecal degradation and nutrient return to soil at 0, 28, 56, 84, and 112 days after application were determined. Forage P was not affected by season or treatment (P > 0.10); forage P mass was greater in cool than warm season. Phosphorus intake and water-soluble P output were not affected (P > 0.10) by season or treatment. Phosphorus output increased (P = 0.087) with increasing N in cool season, but not warm season. Soil P was greater (P