The effect of lime and fertilizers on six lignite overburdens under drained conditions: I. Yield and nutrient concentration of subterranean clover

Abstract

A greenhouse study was conducted to evaluate the fertility status of six overburdens from the potential lignite mining area of Louisiana. Subterranean clover (Trifolium subterranean L. cv. woogenellup) was grown in 2.5 kg of each overburden material which was treated with 0, lx, 2x, 4x and 8x the recommended rate of fertilizer containing P and K based on state soil test analyses. Plants were grown for 14 weeks and harvested to evaluate dry matter yield and mineral composition.

Yield and nutrient concentration were significantly (α = 0.01 and 0.05, respectively) affected by increasing rates of fertilizer in all overburdens. Generally, as the applied fertilizer increased, the yield and nutrient concentration increased.

Chemical properties and nutrient supplying potential of some of the overburdens were misleading. Recommended rates failed to supply sufficient nutrients to support vigorous plant growth on all overburdens except Prairie Terrace and Hall Summit Oxidized.

The results of this experiment indicated that the Prairie Terrace and Hall Summit Oxidized materials were the best growing media for the subclover based on the following: (a) recommended rates of fertilizer containing P and K were sufficient to obtain a good stand that would probably be adequate to control soil erosion, (b) chemical conditions of these two materials were less difficult to manage and (c) standard soil testing techniques satisfactorily predicted their fertility status.

Key words:

• Surface mine reclamation
• Trifolium subterranean
• lignite soils