Growth response of Pinus elliottii open pollinated families to mid-rotation fertilization

Objective To study the effect of mid-rotation fertilization on the growth of Pinus elliottii open pollinated families, and compare the differences of P fertilizer and liming.

Method Three different treatments (NK as control, NK+Ca-Mg-P, NK+liming) were conducted in a 13-year P. elliottii open pollinated progeny test stand. The growth characteristics of P. elliottii were examined before and after fertilization, and the nutrition contents were analyzed in soil and needle.

Result Mid-rotation fertilization had a significant effect on the increments of height, DBH and volume, while the interaction effect between family and treatment was not significant. Compared to NK treatment, NK+Ca-Mg-P and NK+liming significantly increased the height increment by 37.1% and 29.5% respectively, while the latter increased the volume increment by 22.5%. Meanwhile, the DBH increment of NK+liming treatment was higher than that of NK+Ca-Mg-P treatment.

Conclusion Liming with NK fertilizers can increase the timber yield of P. elliottii. The promotive effect of liming on growth of P. elliottii might be related to P instead of Ca.