The effect of crop type, crop rotation, and tillage practice on runoff and soil loss on a Vertisol in central Queensland

Abstract

In 1982, a long-term project was established in central Queensland to study the effect of crop type, crop rotation, and tillage practice on runoff and soil loss. Runoff and soil loss were measured at the outlet of 9 large contour bay catchments (approximately 13 ha) where wheat, sorghum, and sunflower were grown in 3 crop sequences. Each crop sequence consisted of zero, reduced, and conventional tillage fallow practices. Monoculture cropping was practised from 1983 to 1985, then opportunity cropping from 1986 to 1993. During the study, wheat cropping had lower average annual runoff and soil loss (P < 0·01) than sorghum and sunflower. Zero and reduced tillage retained more crop stubble (median >50%) and had less soil loss (P < 0·05) than conventional tillage. Zero tillage wheat had the lowest average annual runoff and soil loss, and conventional sunflowers had the highest. The erosion risk associated with sunflowers was reduced by a wheat–sunflower crop rotation, particularly when zero-tilled. Monoculture sunflower must be avoided. The region is susceptible to large episodic erosion when crops are not sown, there are long fallows, and soil cover falls below levels critical to control erosion (<30%). Opportunity cropping is the most appropriate system to maximise the regions variable rainfall and reduce runoff and soil loss.

Effects of subsurface drip irrigation rates and furrow irrigation for cotton grown on a vertisol on off-site movement of sediments, nutrients and pesticides

“…However, in our study most of the soil loss was limited to irrigation events as the rainfall recorded in both seasons was very low compared to that of previous years. Carroll et al (1997) also suggested that some run-off and soil erosion is ubiquitous for furrow irrigation in heavy clay soil, even in the absence of rainfall. Our experiments showed that run-off and soil erosion can also occur in subsurface drip irrigation cropping when the irrigation rate greatly exceeds the daily crop evaporative demand.…”

“…Field studies in similar soils by Carroll et al (1995Carroll et al ( , 1997 evaluated the effect of crop type, rotation and tillage practice as well as furrow length on run-off and soil losses in furrow irrigated cotton. Research works by Connolly et al (2001), studied the severity of insecticide transport from cotton fields with furrow irrigation.…”

Using zero tillage, fertilisers and legume rotations to maintain productivity and soil fertility in opportunity cropping systems on a shallow Vertosol

“…Conservation cropping systems have 2 major benefits besides reducing soil erosion. First, they increase the number of sowing opportunities and facilitate the use of opportunity cropping systems, whereby crops are planted when the opportunity arises, in contrast to the traditional fixed rotation systems of southern Australia (Carroll et al 1997). Second, reduced runoff can be accompanied by increased infiltration of soil water, thereby leading to greater crop yield potential (Thomas et al 1990a).…”

“…The development of zero tillage (ZT) and stubble retention (or conservation cropping) practices can greatly reduce soil erosion on these cracking clay soils (Freebairn and Wockner 1986;Carroll et al 1997). Conservation cropping systems have 2 major benefits besides reducing soil erosion.…”

Impact of soil conditions on hydrology and water quality for a brown clay in the north-eastern cereal zone of Australia

“…It was expected that results from this study would complement the expanding database from related catchment and tillage studies in Queensland and northern New South Wales (Thomas et al 2007). This study has many elements in common with catchment studies near Capella (Sallaway et al 1990;Carroll et al 1997) and Theodore (Lawrence et al 1994;Cowie et al 2007) in Central Queensland, and Greenmount and Greenwood on the eastern Darling Downs (Freebairn and Wockner 1986a).…”