April 1982
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12 Reads
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47 Citations
(1) Areas which had previously been reclaimed from colliery spoil and urban clearance materials, were dressed with nitrogen, phosphorus and potassium in factorial combination to fourteen sites; each site showed a substantial and over-riding deficiency of nitrogen. (2) Retreatment in the subsequent year showed a continued major need for nitrogen and some deficiency of phosphorus on the colliery spoil. Considerable nitrogen deficiency was also found on two urban sites where topsoil had been used. (3) Some of the colliery spoil sites had become very acid due to oxidation of pyrite, but surface limestone treatments failed to penetrate and therefore failed to have any effect. Adequate limestone must therefore be added during initial reclamation. (4) Nutrients cannot be added in this manner and there is an obvious need for legumes and appropriate aftercare in reclaimed sites to build up nutrients to levels allowing adequate cycling. (5) Aftercare, extending for several years, must therefore be an integral part of all reclamation programmes.