Location: Tropical Crops and Germplasm ResearchTitle: Dry Matter Production and Leaf Elemental Concentrations of Rambutan Grown on an Acid Ultisol Author
Submitted to: Journal of Plant Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2010
Publication Date: 2/6/2011
Citation: Goenaga, R.J. 2011. Dry Matter Production and Leaf Elemental Concentrations of Rambutan Grown on an Acid Ultisol. Journal of Plant Nutrition. 34:753-761. Interpretive Summary: The most productive soils of the world are already under cultivation, and those available for agricultural expansion are often strongly acid, possessing toxic levels of soil aluminum and/or manganese. These elements could drastically reduce crop yields when present in the soil at high concentrations. Incorporation of lime to the soil is a common practice to ameliorate acidity but it is not very effective below the plough layer and often lime is not available to farmers with limited resources. The effect of soil acidity factors on dry matter production and leaf nutrient composition of four rambutan cultivars was assessed during a 2-year field study. High levels of soil acidity did not affect growth and dry matter production of rambutan seedlings. The results of this study demonstrate that rambutan is highly tolerant to acid soils and that tolerance may involve a physiological process to keep toxic Al and Mn from entering the roots. This study provides for the first time useful information to Extension Agents and growers about the adaptability of rambutan to acid soils.
Technical Abstract: Little is known about the adaptability of rambutan (Nephelium lappaceum) to highly acidic soils rich in aluminum (Al). A 2-yr field study was conducted to determine the effects of various levels of soil Al on dry matter production, plant growth, and nutrient concentration in the leaves of four cultivars of rambutan. Cultivars and the cultivar x year interaction were not statistically significant for most variables measured in the study. Total, leaf, petiole, stem and root dry weights significantly increased at soil Al, the concentration ranging from 0.67 cmol kg-1 to 11.0 cmol kg-1. At this range of soil Al, the concentrations of Al and Mn in leaf tissue declined sharply. The results of this study demonstrate that rambutan is highly tolerant to acid soils and that tolerance may involve an Al- and Mn-exclusion mechanism.