Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/10/2011
Publication Date: 10/23/2011
Citation: Jabro, J.D., Stevens, W.B., Iversen, W.M., Evans, R.G. 2011. Bulk density, water content and hydraulic properties of a sandy loam soil following conventional or strip tillage. Applied Engineering in Agriculture. 27(5):765-768.
Interpretive Summary: The effects of conventional (CT) and strip (ST) tillage practices on bulk density ('b), water content ('w), infiltration rate (Ir) and hydraulic conductivity (Ks) were evaluated in a Lihen sandy loam soil during the 2007 and 2008 growing seasons. Soil 'b and 'w did not significantly differ between CT and ST in either 2007 or 2008 with the exception of 'b in 2007. Soil 'b was numerically lower in ST plots than in CT plots while 'w was greater for ST than for CT in both years. Soil Ir was significantly affected by tillage at P < 0.1 in 2007 while Ir did not differ significantly between CT and ST practices in 2008. The effects of tillage on soil Ks were significant in 2007 and 2008 at P < 0.05 and at P < 0.1, respectively. The Ir and Ks values were greater in ST plots than CT plots in both years. The variation in Ks values in soil was likely due to differences in soil compaction and vehicular traffic passes peculiar to the CT and ST systems. The ST plots likely had better volume of macropores than CT plots, producing greater water flow through the ST soil profile.
Technical Abstract: We evaluated the effects of conventional (CT) and strip (ST) tillage practices on bulk density ('b), water content ('w), infiltration rate (Ir) and hydraulic conductivity (Ks) of plots in a Lihen sandy loam soil during the 2007 and 2008 growing seasons. We measured 'b and 'w using soil cores collected from each plot at 0 ' 10 and 10 ' 30 cm depths under each tillage practice. In-situ Ir and Ks measurements were determined using a pressure ring infiltrometer (PI) and a constant head well permeameter (CHWP) at soil surface (0 ' 10 cm) and 10 – 30 cm depths, respectively. Soil 'b in 2008 and 'w in both years did not differ significantly between either practices although a difference in 'b was observed in 2007. The log-transformed Ir was significantly affected by tillage at P= 0.1 in 2007 but did not differ significantly between CT and ST practices in 2008. The effects of tillage on log-transformed Ks were significant in 2007 and 2008 at P = 0.05 and P = 0.1, respectively. The soil Ks values were 68% and 56% greater for ST than for CT in 2007 and 2008, respectively. It was concluded that the CT operations increased soil compaction, which consequently altered 'b, thereby reducing Ir and Ks in the soil.