Improvements to furrow press performance

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.