Browsing by Author "Hue, N."

Now showing 1 - 4 of 4
  • Aluminum detoxification with green manures
    Hue, N.; Amien, I. (Taylor & Francis, 1989)
    A greenhouse experiment was conducted to evaluate "liming" potential of different green manures. Ground leafy materials of cowpea (Vigna unguiculata), leucaena (Leucaena leucocephala) and guinea grass (Panicum maximum) were added at 0, 5, 10 and 20 g/kg to an Ultisol having a soil water pH 4.0, Kcl-extractable Al = 7.6 cmolc/kg, Al saturation = 50% and soil-solution Al = 2.2 mM. Treatments with Ca(OH)2 were established for comparison. Sesbania cochinchinensis, an Al-sensitive tree legume, was grown for 4 weeks as a test crop. Biomass production and chemical composition of the soil indicated that (i) cowpea and leucaena were more effective than guinea grass in detoxifying Al; for example, the additions of 10g manure per kg soil were equivalent to 1.8 cmol(OH)/kg for guinea grass, 3.4 for cowpea and 4.2 for leucaena (at least on a short-term basis), (ii) reduction of soluble Al at increased pH as a result of manure additions was the major mechanism for Al detoxification, and (iii) complexation of soluble Al by organic molecules also contributed to the detoxification.
  • Comparative effects of green manure and lime on the growth of sweet corn and chemical properties of an acid oxisol in Western Samoa
    Hunter, D.; Yapa, L.; Hue, N.; Eaqub, M. (Taylor & Francis, 1995)
    Liming values of calcium carbonate (CaCO3) and cowpea green manure were evaluated on an acid Oxisol (Typic Acrorthox, Togitogiga series), based on seed yield and tissue composition of sweet corn (Zea mays), and soil chemical properties. Application rates were 0, 5, and 10 Mg/ha for CaCO3 and 0, 7.5, and 15 Mg/ha for the green manure, factorially arranged. Treatments with commercial NPK fertilizers were included for comparison. Growth and yield of sweet corn showed that soil acidity can be corrected by either lime or green manure additions. Both lime and manure raised soil pH and (modified Truog) extractable phosphorus (P), which were partially responsible for yield increases. Green manuring significantly increased plant P and potassium (K) concentrations, which explain why the manure was more effective than lime in increasing corn yield. Ear leaves sampled at tasseling required at least 0.25% P and 2.4% K to attain >90% of the maximum seed yield.
  • Liming potential of composts applied to an acid Oxisol in Burundi
    Van den Berghe, C.; Hue, N. (JG Press, Inc., 1999)
    The adverse effect of soil acidity on plant growth and yield, and the scarcity of commercial agricultural lime (CaCO3) in Burundi necessitated a search for alternative liming materials. Thus, the liming potential of locally-made composts was evaluated in a greenhouse experiment, using an acid Oxisol with sorghum (Sorghum vulgaris) as a test plant. Application rates were 10 g/kg (approximately 20 ton/ha) for the composts and 0, 0.85 and 1.70 g/kg for Verrundi lime. Results showed that the application of lime increased plant growth by reducing exchangeable Al, and by increasing soil pH and available P. So did the composts, which were more effective in correcting soil acidity when they were fresh and enriched with some nutrients during the composting process. Apparently, organic molecules produced by the composts helped to chelate and/ or precipitate Al, making the soil more suitable for plant growth. Specifically, an application of 20 ton/ha of composts was equivalent to 0.6- 1.7 ton CaCO3/ha, depending on the compost quality.
  • Practical methods of estimating organic C in soils of the Sahel, West Africa
    Konaré, H.; Hue, N.; Yost, R.; McCarthy, G.; Kablan, R. (1994)
    This presentation summarizes research with the following objectives: (1)to compare three methods of soil carbon determination in West African soils, (2)to evaluate the Loss On Ignition (LOI) method of measuring soil organic carbon, and (3)to explore ways to increase LOI calibration in West African Soils. Conclusion: LOI has significant advantages over combustion and Walkley and Black methods in its ease and technical simplicity and its environmental friendliness.