TITRATION CURVES OF DIFFERENT ORGANIC SUBSTRATES
Pot amendment trials are performed by adding amounts of dolomite or micronized sulphur in relation with titration curves to achieve final pH of 5.5, 6.0 and 6.5.
According to titration curves, base demand of Turbyg peat was higher than Neuhaus due to its greater humic acid content. The superior acid demand for Burés forest litter versus I.M.C. pine bark can be attributed to differences in the base saturation of its exchange complex.
Amendment ability (%) was lower than 100 % for all substrates and desired pH. The lack of effectiveness of dolomite can be explained, in a great extent, by particle size effects while for micronized sulphur it seems to be due mainly to the kind of substrate and its own buffering capacity. The influence of other factors on amendment effectiveness are discussed.