RESEARCH ON SUPPLEMENTARY TECHNIQUES FOR INTENSIVE MACADAMIA CULTIVATION IN CAO BANG PROVINCE

Abstract

Macadamia integrifolia Maiden & Betche is a valuable multi-purpose tree, with large-scale plantating from the Northwest to the Central Highlands, but currently not popular in Cao Bang province. Research results on Macadamia plantation in Cao Bang province showed that the amount of basal fertilizer and planting method affected the survival rate, root diameter (D₀₀), crown height (H_vn), canopy diameter (Dt) and quality. The growth indicators of the basal fertilizer formula of 50 kg of decomposed manure + 0.5 kg of NPK (16:16:8) + 0.3 kg of lime powder for each tree was the best after 18 months of planting with a survival rate of 97.85%, D₀₀ of 3.24 cm, and H_vn of 2.02 m. Dt in CT2 (Basal fertilization with 0.05 kg AM product + 30 kg decomposed manure + 0.5 kg NPK (16:16:8) + 0.3 kg lime powder for each tree) was slightly higher than CT1 (basal fertilizer formula of 50 kg of decomposed manure + 0.5 kg of NPK (16:16:8) + 0.3 kg of lime powder for each tree). The agroforestry planting method generally had higher growth indicators than monoculture planting method. After 18 months of planting, the survival rate, D₀₀, H_vn, Dt of this method reached 97.85%, 3.38 cm, 2.18 m and 1.63 m respectively. Combining agroforestry with short-term agricultural crops and basal fertilizing (50 kg of decomposed manure + 0.5 kg of NPK (16:16:8) + 0.3 kg of lime powder)/tree should be encouraged for expanding intensive cultivation of this valuable tree species in Cao Bang province.