Effects of Nitrogen and Sulfur Fertilizers on Sulfur Content of Tall Fescue and Phalaris¹

Abstract

In an experiment to determine the effect of N and S fertilizer rates on yield and S uptake by cool‐season forage grasses, two cultivars of tall fescue (Festuca arundinacea Schreb.) and one of phalaris (Phalaris aquatica L.) were grown in greenhouse and field experiments on a Cahaba fine sandy loam (Typic Hapludult) at comparable fertility levels. Fertilizer rates in the greenhouse were 38, 75, 125, 175 ppm N and O, 5, 10, 20 ppm S. Nitrogen rates in the field were 85, 170, 280, 390 kg/ha; and S rates were 0, 11, 22, 44 kg/ha. Organic‐S content of foliage was about equal in greenhouse and field experiments; it progressively increased with higher N rates but not with S rates. Inorganic‐S content was much higher in the green. house experiment,. particularly with phalaris; it progressively decreased with N rates and increased with S rates. Phalaris accumulated potentially toxic levels (to ruminants) of sulfate in the greenhouse but not in the field. Greenhouse‐grown plants accumulated much higher levels of S than did field‐grown plants, probably because the field soil was able to retain only a portion of the fertilizer sulfate within the rooting zone of the soil profile.

Multinutrient Fertilization and Placement to Improve Yield and Nutrient Concentration of Tall Fescue

“…Sulfur concentrations increased from 1.06 for the control to about 1.4 g kg-1 with the addition of N, NP, or NPK. Burmester et al (1981) also found that adding fertilizer N increased foliage organic-S concentrations. The NPKSBZn treatment elevated S concentrations to more than 2 .I g kg-1 , but S contents with the PKSBZn treatment were not significantly greater than those for the control.…”

Sulfur-supplying capacity of soils and critical sulfur values of forage crops

“…The concentration of available-S in soil needed for optimum plant growth, however, varies with the forage crops (Fox et al 1977). While, the minimum internal S requirements for plants also seem to differ among species (RAs-MUSSEN et al 1977;BURMESTER et al 1981).…”

Sulfur Source and Placement Effects on Forage Yield and Quality of Established Tall Fescue

“…Sulfur concentrations increased from 1.28 g kg-1 for the control to an average of 1.61 g kg-1 with the addition of N alone. Burmester et al (1981) also found that adding fertilizer N increased foliage S concentrations. Adding A TS further elevated S concentrations to 2.01 g kg-1 , but the response to AS was less and was significant only at the 0.10 level.…”