Seed coating and localized application of phosphate for improving seedling growth of grasses on acid, sandy red earths

Abstract

The seedling growth of tropical grasses on acidic, sandy red earths was improved greatly by the application of small amounts of phosphate fertilizers in close proximity to the seed. Fertilizer had to be applied within 5 cm of the seed of Anthephora pubescens to have any effect. Many phosphorus sources stimulated seedling growth of Cenchrus ciliaris when applied as coatings to the fascicle (the propagule containing the grain). Water-soluble orthophosphates proved the best phosphorus sources for the purpose. Optimum rates of coating ranged up to 2 mg phosphorus per fascicle (10 mg monosodium phosphate), depending on the availability of surface soil moisture. Valuable grasses such as C. ciliaris could be introduced into millions of hectares of native pastures on infertile, sandy soils in north-eastern Australia, at reasonable cost, if a suitable commercial coating process can be developed.