Root Characteristics of Perennial Warm-Season Grasslands Managed for Grazing and Biomass Production

Agronomy

Catherine Bonin¹  Joao Flores²  Rattan Lal¹ 

[1] Carbon Management and Sequestration Center, The Ohio State University, 210 Kottman Hall, 2021 Coffey Rd, Columbus, OH 43210, USA; E-Mail:;Crop and Soil Environmental Science, Virginia Tech, 330 Smyth Hall (0404), Blacksburg, VA 24061, USA; E-Mails:

关键词: prairie plants;    minirhizotron;    roots;    grazing;    biofuels;   

DOI  :  10.3390/agronomy3030508

来源: mdpi

【 摘 要 】

Minirhizotrons were used to study root growth characteristics in recently established fields dominated by perennial C4-grasses that were managed either for cattle grazing or biomass production for bioenergy in Virginia, USA. Measurements over a 13-month period showed that grazing resulted in smaller total root volumes and root diameters. Under biomass management, root volume was 40% higher (49 vs. 35 mm³) and diameters were 20% larger (0.29 vs. 0.24 mm) compared to grazing. While total root length did not differ between grazed and biomass treatments, root distribution was shallower under grazed areas, with 50% of total root length in the top 7 cm of soil, compared to 41% in ungrazed exclosures. These changes (i.e., longer roots and greater root volume in the top 10 cm of soil under grazing but the reverse at 17–28 cm soil depths) were likely caused by a shift in plant species composition as grazing reduced C4 grass biomass and allowed invasion of annual unsown species. The data suggest that management of perennial C4 grasslands for either grazing or biomass production can affect root growth in different ways and this, in turn, may have implications for the subsequent carbon sequestration potential of these grasslands.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.