Sulfur Accumulation in Tall Fescue, Orchardgrass, and Alfalfa1
- P. E. Barney,
- L. P. Bush and
- J. E. Leggett2
Sulfur nutrition of forages and its utilization by animals are poorly understood. The availability of S to animals apparently is different among forage species. Sulfur accumulation and distribution were examined in seedlings of tall fescue (Festuca arundinacea Schreb.), orchardgrass (Dacfylis glomerata L.), and alfalfa (Medicago sativa L.). Seedlings were grown in half-strength Hoagland's No. 1 solution with or without 0.5 mM SO4 added to the nutrient solution. When the seedlings were approximately 1 month old, S accumulation kinetic and pH studies were conducted utilizing 35S-SO4 to measure S accumulation in shoots and roots. Sulfur accumulation in plant parts and accumulation rates were higher in those plants previously grown without SO4 than in those plants previously grown with SO4. The differences were due to a greater concentration gradient between the nutrient solution and the plant tissue of those plants previously grown without SO4 than those grown with SO4. Apparent SO4, absorption sites or carriers were saturated between 0.05 and 0.5 mM SO4. The SO4 absorption mechanism of alfalfa appeared to be different than the SO, absorption mechanism of the grasses because increased solution pH decreased S accumulation by alfalfa, but had no effect on S accumulation by the grasses. The ratio of shoot to root S accumulation per unit dry weight during the experimental period was as much as three times greater in tall fescue than in the other species.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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