Planter Depth Control: II. Empirical Testing and Plant Responses

Abstract

ABSTRACT PLANTING depth control innovations are needed to improve the reliability of performance of no-tillage planters and drills. Four depth control designs were empirically evaluated with grain sorghum and corn crops in two different field conditions. An experimental no-tillage planter opener was used with each depth control. The field surface undulations were characterized prior to planting. Wheat stubble had higher frequency undulations than sorghum stubble. Stubble type affected mean planting depth and caused a shift in frequency distributions of planting depths for front and linked wheels. Dual rear presswheels malfunctioned by sinking into loosened soil and produced deeper and the most variable planting depths. Dual front depth control wheels gave significantly more variable planting depths than the side wheels and linked wheels at the highest applied downpressure. The best choice for depth control remains undecided between traditional wide dual side wheels and narrow experimental linked front-rear wheels. These results generally agree with simulation results from Part I of this series of papers