dc.description.abstract |
The objective of this project was to, improve the performance of the
furrow press, with particular regard to three applications:
i) consolidation in light land
ii) clod breaking in clay soils
iii) tilth production in medium soils
Work conducted by Ansell (1986) led to the suggestion that a press
consisting of different diameter wheels on the same axle might
satisfy some or all of these requirements.
This project began by studying the action of a press in two
dimensions (horizontal-vertical plane) using short sections of press
wheels in a glass sided soil tank. Different combinations and
spacings were considered and their effectiveness measured by breaking
clods in the soil. Different shaped sections were also tested, using
loose soil to study the effect of shape on soil movement.
Following the two-dimensional testing, a range of different diameter
press rings were tested in the Silsoe College Soil Bin. A number of
diameter /spacing combinations were used, and each was evaluated at
three different weight levels. The resulting soil profiles were
measured, together with plate penetrometer tests as an indicator of
soil density.
It was found that an excess of weight could cause a reduction in
average soil strength by greatly reducing surface bulk density.
Using the combinations selected from the work in the soil bin a
number of full width presses were tested on seven field sites,
ranging from a very sandy loam to a wet clay loam. Profiles were
measured before and after passing a tractor over the work. The
sinkage was proportional to the soil strength. Photographs were
taken and analysed to rank the treatments in terms of clod size
reduction.
Evaluation of the field trials has led to the development of a
composite press with a geometry and weight arrangement that has
produced significant improvements in light land consolidation, clod
size reduction and tilth production. |
en_UK |