BIOMASS AND CHEMICAL COMPOSITION OF FERTILIZED AND/OR IRRIGATED

Estimates were made of the above-ground biomass and contents of ash, N, P, K, Ca, Mg, Na, Mn, Al, Fe, Zn, and Cu by plant components for a 40year-old Pinus resinosa Ait. plantation growing on a known K-deficient site and treated with KCl fertilizer and/or irrigation. Regression equations were developed from sample-tree data, obtained by total tree analysis techniques, for each tree component on each treatment. After an examination of analytical techniques, it was determined that the contents of the fertilized trees increased more than 1 40 per cent K, 70 per cent Mn, and 50 per cent N compared to the nonfertilized trees, while the increases in contents of the other elements were more closely related to the 22 percent increase in the biomass of the fertilized trees. The approximate ratio of contents of elements in the total above-ground biomass, expressing Cu = 1, was Ca 1000, N 800, K 260, P 90, Mn 90, Mg 75, Al 50, Na 20, Fe 15, Zn 8, Cu 1 . The 75 kg per ha more K in the above-ground biomass of the fertilized trees compared to nonfertilized trees was about 15 per cent of the total K applied in the fertilizer. The influence of irrigation on the biomass and chemical composition of the trees was minimal.