EFFECT OF DIFFERENT AMENDMENTS ON YIELD AND COMPOSITION OF OATS GROWN ON A SOIL DERIVED FROM SERPENTINE MATERIAL

Abstract

Additions of Ca(OH)₂ and/or organic matter to an unproductive soil with a high content of extractable Ni and a low Ca:Mg ratio (< 0.5) increased the yield of oat tops about four-fold, doubled the Ca:Mg ratio (0.4 to 0.8) and markedly reduced the concentration of Ni in the plants. These changes in the plant were associated with marked reductions in extractable Ni and a two-to five-fold increase in the Ca:Mg ratio in the soil after cropping. Additions of CaSO₄ improved Ca:Mg ratios in both plants and soil but had little effect on yield. Apparently, the higher soil pH following addition of Ca(OH)₂ and the complexing effect of organic matter were each effective in reducing Ni toxicity.