Nitrogen Fertilization Effect on Phosphorus Remediation Potential of Three Perennial Warm-Season Forages

• Published in: Agronomy journal Vol. 101; no. 5; pp. 1243 - 1248
• Main Authors: Newman, Y.C, Agyin-Birikorang, S, Adjei, M.B, Scholberg, J.M, Silveira, M.L, Vendramini, J.M.B, Rechcigl, J.E, Sollenberger, L.E
• Format: Journal Article
• Language: English
• Published: Madison American Society of Agronomy 01.09.2009
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; C4 plants; Cynodon nlemfuensis; dairy manure; fertilizer rates; forage crops; forage grasses; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; hay; Hemarthria altissima; limpograss; Nitrogen fertilization; nitrogen fertilizers; Nitrogen, phosphorus, potassium fertilizations; nutrient excess; nutrient uptake; Paspalum notatum; pasture plants; pastures; pensacola bahiagrass; phosphorus; phytoremediation; plant nutrition; retention; soil fertility; soil pollution; Soil-plant relationships. Soil fertility. Fertilization. Amendments; soils; spodosol; warm season grasses; Florida; Non metal; Group VA element; Nitrogen fertilization; Heat; Agronomy; Phosphorus; Warm season; Remediation
• ISSN: 0002-1962; 1435-0645
• DOI: 10.2134/agronj2009.0117

Warm-season C4 grasses are capable of removing excess soil nutrients because of their high yield potential and nutrient uptake efficiency. Bahiagrass (Paspalum notatum Flügge), limpograss [Hemarthria altissima (Poir.) Stapf & Hubb], and stargrass (Cynodon nlemfuensis Vanderyst), three commonly used pasture grasses in South-Central Florida, were grown to examine the effect of increasing N rates on herbage production and soil P removal. Nitrogen was applied at rates of 67, 90, and 134 kg N ha-1 harvest-1, representing 1, 1.3, and 2 times the recommended N fertilizer application rate for hay production. During 3 yr of evaluation, all three grasses showed a positive P-removal potential that increased with increasing N fertilizer application. Phosphorus removed by forages over the 3-yr period for the highest N application rate was 106, 132, and 147 kg ha-1 for limpograss, bahiagrass, and stargrass, respectively. Mehlich 1 extractable P from the Ap horizon of all plots decreased by as much as 80% of the initial P load over the study period; only 15 to 17% of which appeared to leach to subsurface horizons. Nitrogen application enhanced P uptake and consequently reduced P transport to deep (>13 cm) soil depths. These data indicate that stargrass, bahiagrass, and limpograss managed intensively for hay production represent effective options in removing excess soil P from P-impacted sites.