ENHANCEMENT OF WHEAT ESTABLISHMENT WITH MODIFIED SOWING AND FALLOW MANAGEMENT-TECHNIQUES

Modified fallow management practices and modified sowing techniques we re used to enhance wheat (Triticum aestivum) establishment in dry cond itions. The effects of tillage, stubble management, deep sowing and pr ess wheel pressure on wheat establishment were examined at various per iods after rain. Experiments were conducted on two contrasting soil ty pes: an Entic Pellustert and a Typic Natrustalf. On the Entic Pelluste rt, both tillage during the fallow and the use of a press wheel at sow ing increased wheat establishment. Responses to tillage and the press wheel occurred even when there was enough post-sowing rain to wet the soil to the level of seed placement. Increase in sowing depth from 67 to 88 mm reduced establishment in most sowings. On the Typic Natrustal f, there was little establishment response to tillage, a mulch of whea t stubble or the use of press wheel pressure at sowing. However, an in crease in sowing depth from 54 to 74 mm maintained a given level of es tablishment for an additional 10 days of soil drying after rain. Deep furrow sowing (placement of seed over 100 mm below the original soil s urface) did not improve establishment on either soil type. On both soi l types, soil matric potential and establishment at a particular sowin g depth were significantly correlated (R(2) = 0.91 and 0.68, respectiv ely), indicating that differences in establishment were caused primari ly by the impact of the treatments on seed bed water levels.