Relations between the yield of pine and Ca-Al ratio in the growth environment and plants

Relations between the yields of pine and Ca/Al ratio were studied in two experiments. In the first exper­iment one-year-old pine seedlings were grown in soil-water cultures. The source of elements was the soil from O, AE and Bv horizons sampled under pine stands. In the second experiment two-year-old pines were culti­vated in quartz sand and increasing doses of Al were added. The results showed that the yield of one-year-old pine was not related to the Ca/Al value, neither in soil solution nor in plants. Increasing doses of Al from 2 to 100 mg Al kg-1 decreased the yield from 42 g to 13 g d.w. and Ca/Al values from 8.1 to 1.0 in needles, from 4.4 to 1.0 in shoots and from 0.63 to 0.07 in roots. The correlation coefficient between Ca/Al and yield of nee­dles was 0.850, between Ca/Al and yield of shoots was 0.867 and between Ca/Al and yield of roots was 0.712.