|Pikul Jr, Joseph|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/18/2005
Publication Date: 11/8/2005
Citation: Riedell, W.E., Pikul Jr, J.L., Osborne, S.L., Schumacher, T.E. 2005. Till and no-till soil management effects on soil physical properties and corn yield. Agronomy Abstracts #1529.
Interpretive Summary: Soil compaction, which results when loads applied to a soil are greater than the soil bearing strength, is a process whereby soil particles are pushed closer together and thus the amount of soil pore space is reduced. Compacted soils generally have higher bulk density and lower levels of water movement and oxygen than soils that are not compacted. These changes in soil physical properties, combined with increased mechanical impedance, can create unfavorable growing conditions for crop roots, which in turn can cause crop yield reductions. Soil penetrometer resistance, which is a measure of the amount of force needed to push a soil probe through the soil profile, can be affected by soil bulk density and soil moisture. Generally speaking, more force is needed to push a probe through soils with high bulk density or low soil moisture. No-till soil management is an excellent way to reduce soil erosion by wind and water. However, reports in the literature indicate that soil penetrometer resistance is initially higher in no-till soils than in tilled soils. Our objectives were to measure penetrometer resistance of soil farmed under tilled and no-till soil management, and to investigate the relationship between soil penetrometer resistance and grain yield in corn. We found that soil penetrometer resistance values were higher in plots managed under no-till when compared with tilled plots, and that grain yield was negatively correlated to soil penetrometer resistance. These data reveal the importance of minimizing soil compaction, especially when using no-till soil management.
Technical Abstract: Compacted soils generally have higher bulk density, increased mechanical impedance, and lower levels of water movement and oxygen than soils that are not compacted. Our objectives were to measure soil physical properties of soil under tilled and no-till soil management and to investigate the relationship between these properties and grain yield in corn. Plots were established on a Barnes sandy clay loam soil (fine-loamy, mixed, superactive, frigid Calcic Hapludoll) in 1997. Main plots were soil management with tillage (fall chisel plow and spring disk) or no-till treatments. Soil penetrometer, soil bulk density, and soil moisture measurements were taken within plant rows at the V6 leaf development stage. Relationships between soil penetrometer resistance at different soil depths and corn grain yield were assessed by calculating Pearson’s correlation coefficients. In no-till plots, soil penetration resistance was very close to 1.5 MPa in the top 30 cm, while at deeper depths it ranged from 1.6 to 2.3 MPa. In tilled plots, soil penetrometer resistance ranged from 0.5 to 1.2 MPa in the top 15 cm of the soil profile and 1.2 to 1.5 MPa from 25 to 60 cm soil depth. Correlation coefficients were calculated with grain yield and soil penetrometer resistance (1 to 60 cm soil depth at 5 cm increments) as variables. With the exception of 15 and 20 cm depths (in the region of the plow pan in the tilled plots), probabilities associated with r were highly significant over all depths. Correlation coefficients ranged from -0.47 to -0.67 across soil depths. These coefficients suggest that grain yield was negatively correlated to soil penetrometer resistance. These data reveal the importance of minimizing soil compaction, especially when using no-till soil management.