The growth and nutrients status of conifers on ash-treated cutaway peatland.

摘要

The effect of fertilization with wood ash (10 and 15 t ha-1) and a mixture of wood ash (10 t ha-1) and oil shale ash (8 t ha-1) on the growth (height, root collar diameter, biomass, biomass production) and nutrient concentrations in subsoil and needles of young Pinus sylvestris and Picea abies plants on the Puhatu (Northeast Estonia) cutaway peatland in the first 2 years were studied. After the second growing year differences in the average height growth of P. abies and P. sylvestris were statistically significantly higher on ash-treated plots than on the control plots (p<0.05), being respectively 1.4-1.6 and 1.5-1.7 times greater than height growth of the control trees. The best results on root collar diameter were observed on mixture ash treatments: the root collars were 1.9 (P. abies) and 2.2 (P. sylvestris) times larger than of the control trees. The biomass of the two conifer species and the biomass production of P. sylvestris in 2012 was the greatest on the mixture ash treatments. Five months after fertilization with ashes the concentrations of P, K, Ca and Mg were higher on the treated plots than on the control plot. Although the concentrations of P and K in P. sylvestris needles rose after the treatment with ash, seedlings suffered from P and K deficiency. The concentrations of P and K in P. abies needles were on optimum. The P/N and the K/N ratios in needles were also improved compared to control trees needles.