Performance of a prototype fluid drill

Abstract

Fluid drilling is a novel sowing technique whereby seeds (either untreated or pregerminated) are dispersed in a fluid medium and subsequently extruded into the soil. A theoretical analysis revealed that a commercial tractor-mounted fluid drill is best suited to small seeds and a luminar flow regime. A prototype fluid drill was developed with rotary self-cleaning coulters suitable for operating under sticky soil conditions. Tests on this drill revealed that spacing distributions for cabbage seeds (laboratory) and seedlings (field) were substantially inferior to those obtained using a conventional precision drill. Nevertheless the fluid drilled crop compared favourably with the conventionally grown crop as indicated by visual observations of plant growth and vigour. In addition, emergence of the fluid drilled crop occurred approximately 30% sooner. It was concluded that the commercial acceptability of this drill would be greatly enhanced by the development of a suitable precision fluid drilling mechanism.