David R White

Results From Recent Traffic Systems Research And The Implications For Future Work

Abstract This paper reviews the results of recent traffic systems research and concludes that the evidence shows that with sufficient ingenuity by farmers and their equipment suppliers to match operating and wheel track widths, the traffic management systems that reduce soil compaction should improve crop yield, reduce energy consumption and improve infiltration rates (which will reduce runoff, erosion and flooding). These together will improve agronomic, economic and environmental sustainability of agriculture. Low ground pressure alternatives may well be the option that best suits some farming enterprises and should not be discounted as viable traffic management methods. The paper also considers the implications for further work to improve the robustness of the experimental data.

An investigation into the effect of traffic and tillage on soil properties using X-ray computed tomography

Abstract. Compaction of soils from agricultural machinery alters soil aggregate and pore structure whilst increasing bulk density. This leads to decreased soil aeration and water and nutrient uptake and increases root penetration resistance that can result in reduced crop yields. A randomised 3x3 factorial traffic (Random Traffic Farming, Controlled Traffic Farming and Low Ground Pressure systems) and tillage (Deep, 250mm; Shallow, 100mm and No-till) field experiment at Harper Adams University, UK, was set up in 2011. An investigation was conducted in 2016 using X-ray Computed Tomography (CT) to assess the effects of tillage and traffic on the soil pore size and distribution. The study highlighted that deep tillage reduces the ability of soil to support vehicular traffic which leads to soil recompaction. Deep tillage caused soil percentage porosity to decrease with depth with corresponding increases in the frequency of smaller size pores. Shallow tillage treatments increased the percentage porosity with depth whilst providing the lowest penetration resistance. Percentage porosity is higher in untrafficked treatments. Further investigation is required to investigate the effect that the complex interactions between soil pore structure and developing root architecture have on crop yield.

Preliminary work on the compression behaviour of canola straw to high density products

In the United Kingdom (UK), the total area of canola harvested increased between 2000 and 2008 from 332,000 ha to 598,000 ha, respectively. Currently there is not a significant market for canola straw in the UK, and consequently development of a market for canola straw would add value to the gross margin of the crop at farm level. As a biomass waste product, canola straw could be used as a fuel to generate heat through combustion. However, straw exhibits a low bulk density which makes its transport more expensive than the transfer of natural gas or petroleum. Reducing the cost of collection, transport and storage of biomass through densification is thus critical to developing a sustainable infrastructure capable of working with significant quantities of raw material.

Effect of Pre- and Post-pelletisation Storageof Canola (Oilseed Rape) Straw on the Quality and Properties of Pellets

With the growing demand for biomass for alternative energy supplies, it would be prudent to investigate a range of alternative sources of energy. The current research study, of which this is part, will investigate the effect of pre and post pelletisation storage on the quality and combustion properties of canola (oilseed rape) straw and short rotation coppice willow, which, unlike wood pellets, have had little or no detailed research upon the variation of the physical, chemical, biological and combustion properties over the period of storage. This paper focuses on the effect of storage period on canola straw and canola straw pellets in terms of pellet quality. The quality of canola pellets was assessed in terms of their chemical, biological and physical characteristics. The chemical and biological properties of both straw and pellets, included the determination of moisture content, gross calorific value, ash content, volatile content, biomass temperature development, ambient temperature and bacterial and fungal growth. The physical characteristics of canola straw pellets included their durability, compression resistance, particle and bulk density, particle size and mean pellet length and diameter. The chemical and biological properties of both straw and pellets are presented.