Switchgrass and Big Bluestem Responses to Amendments on Strongly Acid Soil
- G. A. Jung *,
- J. A. Shaffer and
- W. L. Stout
Native perennial warm-season grasses are established and used in the northeastern United States for beef cattle (Bos taunts) production, wildlife habitat, and soil conservation. This research was conducted in Pennsylvania to study select plant growth responses and forage quality of switchgrass (SWG), Panicum virgatum L., and big bluestem (BBS), Andropogon gerardii Vitman, to dolomitic lime, and P and N fertilizers on strongly acid, fine-loamy, mixed, mesic, Typic Fragiaqualfs. The soil amendments were applied after the first growing season. Growth of SWG and BBS was markedly improved by topdressings of lime and N fertilizer. In 1981 and 1982, untreated warm-season grass yielded approximately 50%, and grass receiving the low rate of applied nutrients yielded 90%, of that with the high lime and fertilizer rate (8.76 Mg ha−1). Nitrogen fertilizer increased production of stems and leaf sheaths more than leaf laminae. Crude protein concentration (CPC) of both species generally was low, but N fertilizer increased CPC from 52 to 77 g kg−1. In vitro dry matter disappearance values were low, but significant species × N, lime × N, species × lime × N, and N X year interactions occurred. Lime effects were significant for concentrations of Ca, Mg, and Mn; P fertilizer for Ca, Mg, and P; and N fertilizer for Ca, Mg, P, and Mn. Aluminum concentrations in forage were low even with an exchangeable soil Al of 100 kg ha−1. Approximately 80% of the root mass of each species was within the top 10 cm of soil, but roots were observed growing along prism faces of the fragipan at 60 cm. The warm-season grasses were productive on strongly acid (31 Mg lime ha−1 needed for neutralization), infertile soil, with low inputs of lime (4.5 Mg ha−1) and fertilizer.
Copyright © .