Tolerance of Bermudagrass Selections to Acidity. I. Effects of Lime on Plant Growth and Mine Spoil Material1
- P. E. Lundberg,
- O. L. Bennett and
- E. L. Mathias2
Non-fertile acid soils including many strip-mined spoils are common in the Appalachian region of the USA. Strip mine spoils often have low water holding capacity, no soil structure, and various toxic materials, thus correction of pH and fertility problems may not be economical. Studies involving judicious use of lime and fertilizer and suitable plant species, however, are warranted. The objective of this research was to study the growth of several bermudagrass (Cynodon dactylon (L.) Pers.) selections on strip mine spoil treated with various lime rates. Three cultivars and five strains of bermudagrass were planted in 1 liter pots filled with low pH mine spoil (pH 2.9) treated with six rates of calcitic lime from 2.24 to 13.44 metric tons/ha (1.3 to 7.8 g/pot). All pots were given blanket applications of N, P, K, and Mg, as need was determined from soil analyses. Four harvests were made at approximately 6-week intervals with oven dry weights of both forage and roots taken at the end of the study. All eight selections showed a significant increase in mean root and forage yields up to 6.72 metric tons/ha lime. Higher lime rates than this did not increase forage yields and resulted in lower root yields. Selections differed markedly in their growth response to various lime levels. ‘Tufcote’ outyielded all other selections at the 2.24 metric tons/ha lime rate, but its highest yield was lower than that of any other selection. ‘P.I. 315904’ and ‘Native 1’ grew best over the range of all lime treatments. Soils in which the various selections had grown had significant differences in pH and residual available nutrients. Bermudagrass was found to tolerate very acidic conditions (pH 3.4). The fact that yield made its most dramatic increase through the first three rates whereas pH increased little may indicate it is really the toxicity of certain elements rather than the low pH which limits bermudagrass growth. This study indicates that Tufcote would be a good choice if pH was as low as 3.4, however, at a nearly optimum pH of 4.5 P.I. 315904 or Native 1 would be a much better choice.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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