Impact of P and K nutrition on alfalfa root development. (6388)
Authors:
J.N. Evans* - Purdue University
W.K. Berg - Purdue University, West Lafayette, IN B.C. Joern - Purdue University, West Lafayette, IN
S.M. Cunningham - Purdue University, West Lafayette, IN S.M. Brouder - Purdue University, West Lafayette, IN J.J. Volenec - Purdue University, West Lafayette, IN
Abstract:
Root morphology and nutrient uptake impacts nutrient management decisions and nutrient responses of alfalfa (Medicago sativa L.). Our objective was to determine the effects of P and K fertilization on alfalfa root morphology and physiology. A factorial arrangement of P (0 and 75 kg/ha) and K (0 and 400 kg/ha) treatments was replicated in the field four times in September 2001. In June 2004, soil cores were taken to a 1-m depth, and divided into several increments. Roots were gently washed free of soil, fine roots recovered, and quantified using WinRHIZO to determine root length density. Soil cores were analyzed for P and K concentrations at the corresponding depths. Taproot samples were taken in September 2003 and June 2004 and analyzed for volume, density, and organic reserves. Significant P x K interactions were observed for root length density at specific depths. Taproot volume nearly doubled for plants provided both P and K when compared to plants deprived of both P and K. The relationship between root length density, nutrient distribution in the soil profile, and agronomic performance will be discussed.
Speaker Information: Jamalyn Evans, Purdue University, Department of Agronomy Purdue University 915 West State St., West Lafayette, IN 47907-2054; Phone:
765-496-1489; E-mail: [email protected]
Session Information: Wednesday, November 3, 2004, 2:00 PM-4:00 PM Presentation Start: 2:00 PM (Poster Board Number: 0808)
Keywords: alfalfa; root density; root development; plant nutrition
