Publication Date
1993
Description
A greenhouse study was conducted to test the influence of soil texture (clay loam and sandy loam) and soil fertility status (low and high) on plant growth, dry matter (DM) partitioning between shoots and roots, proportion of legume roots in an association, root length density and net photosynthesis of 3 tropical grass + legume associations: Brachiaria dictyoneura + Arachis pintoi; Andropogon gayanus + Centrosema acutifolium; and Andropogon gayanus + Stylosthes capitata adapted to acid soils. Both soils are characterised by low pH and high aluminium saturation. The sandy loam soil had lower levels of soil organic matter and total nitrogen than the clay loam. Soil texture and fertility status affected biomass production and partitioning of DM between shoots and roots. Al low soil fertility, a greater proportion of fixed carbon was partitioned toward roots, because the leaves maintained normal photosynthetic activity. The results indicate that some tropical grasses in association with legumes adapt to sandy loam soil by increasing root length density as well as root biomass. This strategy enables these associations to be productive on less fertile sandy loam soils by scavenging efficiently for nutrients.
Citation
Rao, I M.; Ayarza, M A.; Thomas, R J.; Fisher, M J.; Lascano, C E.; and Borrero, V, "Adaptation Responses of Tropical Grass-Legume Associations to Acid Soils" (2024). IGC Proceedings (1993-2023). 8.
https://uknowledge.uky.edu/igc/1993/session42/8
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Adaptation Responses of Tropical Grass-Legume Associations to Acid Soils
A greenhouse study was conducted to test the influence of soil texture (clay loam and sandy loam) and soil fertility status (low and high) on plant growth, dry matter (DM) partitioning between shoots and roots, proportion of legume roots in an association, root length density and net photosynthesis of 3 tropical grass + legume associations: Brachiaria dictyoneura + Arachis pintoi; Andropogon gayanus + Centrosema acutifolium; and Andropogon gayanus + Stylosthes capitata adapted to acid soils. Both soils are characterised by low pH and high aluminium saturation. The sandy loam soil had lower levels of soil organic matter and total nitrogen than the clay loam. Soil texture and fertility status affected biomass production and partitioning of DM between shoots and roots. Al low soil fertility, a greater proportion of fixed carbon was partitioned toward roots, because the leaves maintained normal photosynthetic activity. The results indicate that some tropical grasses in association with legumes adapt to sandy loam soil by increasing root length density as well as root biomass. This strategy enables these associations to be productive on less fertile sandy loam soils by scavenging efficiently for nutrients.
