The importance of harvest residue and fertiliser on productivity of Pinus patula across various sites in their first, second and third rotations, at Usutu Swaziland

New Zealand Journal of Forestry Science

Table 6 Correlation coefficients and statistical significance of relationship between needle nutrient concentration (%) and volume production at age 10 years across all treatments and sites of the first trial series established in 1971

	Timber volume at age 10 years	Mg (%)	Ca (%)	K (%)	P (%)
N (%)	0.141	0.083	0.071	0.239	0.198
P (%)	0.349 **	−0.118	0.054	0.493 ***
K (%)	0.541 ***	−0.023	0.318 *
Ca (%)	0.182	0.415 ***
Mg (%)	0.058

* = 5% level, ** = 1% level, *** = 0.1% level (Morris: Trial series B43: Site preparation and fertiliser application at time of planting, Part 2: Influence on needle nutrient content (Unpublished))