The reclamation of acidic colliery spoil. III. Problems associated with the use of high rates of limestone
Published source details
Costigan P.A., Bradshaw A.D. & Gemmell R.P. (1982) The reclamation of acidic colliery spoil. III. Problems associated with the use of high rates of limestone. Journal of Applied Ecology, 19, 193-201.
Published source details Costigan P.A., Bradshaw A.D. & Gemmell R.P. (1982) The reclamation of acidic colliery spoil. III. Problems associated with the use of high rates of limestone. Journal of Applied Ecology, 19, 193-201.
When reclaiming acidic pyritic colliery spoil, to neutralize acidity incorporation of ground limestone is required. However, growth of white clover Trifolium repens (coomonly sown in reclamations) on such spoil has been shown to be inhibited by large applications of agricultural ground calcitic limestone. This may pose difficulties in establishment and maintenance of grass swards as these spoils contains no plant-available nitrogen so there is often a reliance on nitrogen fixation by leguminous herbs, e.g. clovers, to counter this problem. Given results of an earlier experiment that suggest that magnesium deficiency may contribute to growth inhibition of white clover at high liming rates (see: www.conservationevidence.com/ViewEntry.asp?ID=877 for a summary) , the effects of magnesian (dolomitic) limestone application on growth of perennial rye-grass Lolium perenne and white clover Trifolium repens on acidic colliery spoil was investigated.
Acidic, unburnt colliery spoil (pH 3.2) from Ince-in-Makerfield, Greater Manchester (National Grid ref. SD 588036), northwest England, was used to compare the effects of ground calcitic limestone and ground magnesian limestone on L.perenne and T.repens growth.
Prior to application, the limestone powders were sieved (150µm mesh) to ensure particle size comparability. In the rye-grass experiment, calcitic limestone was applied at rates of 12.5, 25, 50, 100 and 200 t/ha; magnesian limestone was applied at slightly lower rates to give the same equivalent and neutralizing effects (1 g magnesian limestone equivalent to 1.06 g calcitic limestone). Phosphorus was applied at 110 and 440 kg P/ha (as triple superphosphate) to investigate possible P-limestone interactions. L.perenne was sown at 200 kg seed/ha after application to the spoil of 125 kg N/ha (ammonium nitrate) and 50 kg K/ha (potassium sulphate). In the clover experiment, calcitic limestone was applied at 5, 10, 20, 40 and 80 t/ha; magnesian limestone was again applied at slightly lower rates.
Both experiments were of randomized factorial design with two replicates using 15 cm plastic pots placed in a glasshouse, watered with deionized water as required. Dry weight production was determined at 6 weeks after sowing.
Dry weight production of L.perenne was 2.7 g/pot after calcitic liming and 4.2 g/pot after magnesian liming (an increase of 56%). Phosphorous fertilizer applied at 110 kg P/ha produced 2.9 g/pot and at 440 kg P/ha produced 3.9 g/pot (an increase of 35%). Magnesian limestone produced marginally higher yields with low P (110 kg/ha) than did calcitic limestone with high P (440 kg/ha), and at 440 kg P/ha improved growth further with magnesian limestone.
Growth of T.repens was also stimulated by magnesian limestone compared with calcitic limestone, but high P addition was needed for satisfactory growth.
Conclusions: Growth of L. perenne was improved and the inhibitory effect of liming on T. repens was alleviated by application of magnesian limestone (dolomite) instead of calcitic limestone. Phosphate adsorption of spoil was similar after low and very high limestone applications but increased by 100% after liming at 25 t/ha to pH 5.1. The authors suggest that phosphate adsorption at pH 5.1 is caused by freshly precipitated, amorphous aluminium hydroxide.
Note: The compilation and addition of this summary was funded by the Journal of Applied Ecology (BES). If using or referring to this published study, please read and quote the original paper, this can be viewed at: http://links.jstor.org/sici?sici=0021-8901%28198204%2919%3A1%3C193%3ATROACS%3E2.0.CO%3B2-2