Factors Affecting the Accumulation of Nitrogen in Colliery Spoil

Publisher Website
Google Scholar
Abstract
Spoil N composition, dry matter yield, herbage N concentration and nitrogen yield were determined in Festuca rubra L. and Lolium perenne L. swards established on colliery spoil. The 7-yr-old swards had been sown with white clover (Trifolium repens L.) or supplied with N fertilizer since establishment. Dry matter yields, nitrogen concentration in the herbage, mineralizable spoil nitrogen and estimates of recently accumulated organic nitrogen were significantly greater on white clover than N fertilizer plots. Dry matter yields and herbage nitrogen yields were also significantly greater on F. rubra plots than L. perenne plots. The converse was true of nitrogen concentration in the herbage, mineralizable N and an estimate of recently accumulated N. White clover plots and fertilizer nitrogen plots had accumulated 376 and 273 kg N ha-1, respectively and unameliorated spoil 58 kg ha-1 since establishment. During this time fertilizer plots had received 500 kg N ha-1 and white clover plots no nitrogen fertilizer. Spoil N components were significantly correlated with herbage yield and N components; the most highly correlated spoil component was mineralizable N. The level of nitrogen accumulation was very low compared to soils but the rate of accumulation was similar to that found on other derelict land. The use of a legume is considered to be the most efficient way of accumulating N in colliery spoil.