A land suitability assessment for tropical forage legumes

Land suitability assessments for forage legume production (genera Stylosanthes, Centrosema, and Desmodium) for 21 Hawaii soils were obtained by using a land suitability classification based on Soil Taxonomy. Land assessments based on four qualities, viz., nutrient availability, water availability, soil acidity and soil thermal regime, indicated that six of the soils were unsuitable for forage legume production without application of agricultural inputs (fertilizer, lime, and irrigation). Nutrient availability was the land quality that most frequently failed to meet the requirements of tropical forage legumes. Application of low levels of input reduced the number of unsuitable soils from six to three, whereas high inputs made all soils suitable for forage legume production. The land suitability assessments were consistent with published field results on forage legume performance in Hawaii. The results suggest that quick and reliable estimates of land use for forage legume production can be obtained wherever Soil Taxonomy is used in available surveys.