Fertilization of Native Grass and Weeping Lovegrass1
- W. E. McMurphy,
- C. E. Denman and
- B. B. Tucker2
Yield responses by native range to fertilization has often been disappointing in the tall grass prairie, and the results were confounded by changes in species composition. This study evaluated the response to N and P fertilizer by monocultures of three native species ‘Kaw’ big bluestem (Andropogun gerardi Vitman), ‘Caddo’ switchgrass (Panicum virgatum L.), and indiangrass [Sorghastrum nutans (L.) Nash] and an introduced grass, weeping lovegrass [Eragrostis curvula (Shrad.) Ness].
Rates of N fertilizer were 0, 45, 90, and 180 kg/ha in all combinations with P at 0 and 40 kg/ha. Forage production, crude protein, fertilizer N recovery, stand longevity, and soil fertility changes were evaluated.
Excellent forage yield responses to N fertilization were obtained from the native species in monoculture. Switchgrass and weeping lovegrass were the most productive species at 180 kg N − 40 kg P/ha, but had different seasonal production. All native grasses produced one flush of growth and very limited regrowth when compared with weeping lovegrass. Indiangrass had significant reductions in stand at 90 kg N and 180 kg N/ha and was the first species each year to show visual symptoms of drought stress. Severe lodging of big bluestem at 180 kg N/ha limited its potential. Fertilizer N recovery of all species was most efficient at the 90 kg N − 40 kg P/ha treatment being 52 to 66% for native grasses and 84% for weeping lovegrass. Soil tests revealed P accumulations with P fertilization, decreased soil pH associated with N fertilizer and soil K changes in relation to forage removal.
The native species have some characteristics which limit their potential for use in fertilized meadows.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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