The self-focusing Fresnel-Dammann grating and the Fresnel binary CGH for compact 2-D light spot array generation

The authors have described the design and demonstrated the performance of two types of lensless array generator. The Self-focusing Fresnel-Dammann grating (SFD), and the Fresnel hologram. The SFD is based on a conventional Dammann grating, but obviates the need for extraneous Fourier transform lenses, by combining the grating with a Fresnel zone plate, in an exclusive-OR fashion. No alignment is required and no bulky or dispersive refractive elements are used. The Fresnel hologram can be designed for high fanout, but the design must take into account the phases of the light spots in the image array. The authors have demonstrated this for an 8times8 fanout element, where a set of random phases in the output gave rise to a satisfactory performance, whilst another set of phases gave an undesired, although interesting, result. The authors have also demonstrated a 30deg slanted axis, random phase design, generating a two dimensional array of 8times8 beams, used in reflection, and operating in a multiple reflection, planar-optic configuratio

The effect of storage on the quality properties of Oilseed Rape straw pellets.

With the growing demand for biomass for alternative energy supplies, it would be prudent to investigate alternative sources of energy. The layer study of which this is part will investigate the effect of pre and post pelletization storage on the quality and combustion properties of oilseed rape straw, 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 time on oilseed rape straw pellets in terms of pellet quality. The quality of oilseed rape straw pellets was assessed in terms of durability, hardness and particle density. Results show the quality of the pellets is affected by storage time. The durability and particle density of pellets increased between 2 weeks and 3 months storage, before decreasing up to 12 months storage. The hardness of pellets continuously increases during the 12 months storage. It is clear storage time influenced the properties of OSR straw pellets, but it is suspected that there are other factors (e.g. binder, raw material, natural variations) that could be affecting these quality parameters

Controlled traffic farming delivers better crop yield of winter bean as a result of improved root development

This paper reports on the continuation of a long–term experiment on the effects of alternative field traffic systems (STP–random traffic with standard tyre inflation pressure, LTP–random traffic with low tyre inflation pressure and CTF–controlled traffic farming) on soil conditions and crop development as influenced by different tillage depths (DEEP–250 mm, SHALLOW–100 mm and ZERO–tillage), in a randomised 3 x 3 factorial design in 4 replicates launched by Harper Adams University in Edgmond, UK, in 2011. The results from season 2017–2018 revealed that CTF delivered 8% higher crop yield of winter field bean (Vicia faba) cv. Tundracomparing to STP (p = 0.005), i.e. 4.13 vs 3.82 tonnes ha-1respectively (at 14% moisture content). The ZERO–tillage plots featured significantly lower plant establishment percentage comparing to shallow and deep tillage: 79% vs 83% and 83% respectively (p = 0.012). The research showed that roots traits differed significantly between contrasting traffic at depths greater than 50mm with p < 0.05of: tap root biomass, number of lateral roots, biomass of lateral roots as well as total root biomass (tap+lateral roots),delivering significantly greater values of those before mentioned parameters on CTF comparing to STP. Tap root length significantly differed between traffic systems (p < 0.001)giving significantly greater results on CTF comparing to LTP and STP (17.7, 13.4 and 12.6 mm respectively). Significant differences in tap root diameter were found only at the depth of 100 mm (p < 0.001) where again CTF delivered significantly higher root diameter than the remaining 2 traffic systems.In the shallow layer of soil (0–50 mm) a significant difference was found only for tap root biomass, for interactions, where STP ZERO gave significantly higher results than STP SHALLOW and CTF SHALLOW (1.430, 0.733 and 0.716 g respectively)

Results from recent traffic systems research and the implications for future work

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

Agricultural traffic management systems and soil health

This chapter examines the relationship between agricultural traffic and soil compaction. It begins by reviewing research on how agricultural traffic affects soil compaction as well as ways of measuring soil compaction and its effects. It then discusses a range of potential techniques to avoid soil compaction. These include: controlled-traffic farming, low ground pressure tyre systems as well as tracks and gantry systems. The chapter also discusses the relationship between different tillage practices and soil compaction. It includes a case study based on research conducted by the authors

The effect of tire inflation pressure and tillage systems on soil properties, growth and yield of maize and soybean in a silty clay loam soil

Soil compaction causes adverse effects on soil structure and the performance of crops. There is significant literature supporting the hypothesis that reducing tire inflation pressure can help to minimize compaction, but there is no data on the potential benefits of high flexion tires operating at reduced tire pressures in Midwestern United States agriculture. Hence, a field-scale study was established in Illinois to determine the potential benefits of high flexion tires at low tire pressure (LTP) in comparison with those operated at standard tire inflation pressure (STP) on soil condition, crop growth and yield of maize and soybean for three tillage systems; deep tillage (450mm), shallow tillage (100mm) and no- till. Two adjacent experiments were established in typical maize/soybean and soybean/maize rotations, respectively. The experiment used a 2 × 3 factorial design with five completely randomized blocks. The results showed that the use of LTP tires resulted in lower soil penetrometer resistance for three tillage systems in 2017 and 2018 in the maize field and 2018 in the soybean field. This improved plant establishment and the number of plants per hectare of maize in both 2016 (*p≤.05) and 2018 (**p≤.01) and plant establishment (***p≤.001) and the number of plants per hectare (***p≤.001) of soybean in 2018. The penetrometer resistance was higher in the no-till plots compared to deep and shallow tillage plots in maize and was higher in the deep tillage plots compared to the shallow tillage in the soybean field. The use of LTP tires resulted in an increased grain yield of maize by 4.31% (15.02Mgha−1) and 2.70% (14.76Mgha−1) in 2017 (**p≤.01) and 2018 (*p≤.05), respectively, and soybean by 3.70% (4.25Mgha−1) in 2018 (*p≤.05). The depth of tillage had a significant effect on soybean and maize yields in 2017 (***p≤.001) and 2018 (***p≤.001), respectively, with higher yields of both soy-bean and maize in the deep and shallow tillage compared to no-till plots. The study concludes that the use of the LTP systems can be a potential means of addressing soil compaction and maintaining soil porosity while increasing crop productivity in silty clay loam soils in Central Illinois

Summary of the effects of three tillage and three traffic systems on cereal yields over a four-year rotation

This paper reports the design and results of a study to consider the effects of deep, shallow and zero tillage with random conventional and low tyre inflation pressures and controlled traffic systems on the yield of winter wheat, winter barley (×2) and spring oats. The results show that crop yields for zero tillage were significantly less (P<0.001) than deep and shallow tillage for all crops with an overall reduction of 1.0 t ha-1 below the mean of the deep and shallow tillage practices. Controlled traffic farming with a 30% trafficked area produced significantly higher yields than random conventional pressure traffic for the winter wheat and spring oats. Controlled traffic farming, with trafficked areas of 30% and 15% showed overall benefits over random conventional inflation pressure traffic of 0.32 t ha-1 (£41 ha-1) and 0.61 t ha-1 (£77 ha-1) respectively, requiring breakeven areas of 312 ha and 168 ha to cover the costs of three vehicle guidance/auto-steering systems

The effects of traffic management systems on the yield and economics of crops grown in deep, shallow and zero tilled sandy loam soil over eight years.

This paper reports on a 3 × 3 factorial study to consider the effects of controlled traffic (CTF), low tyre inflation pressure (high flexion) tyres (LTP) and standard tyre inflation pressure (STP) farming systems for deep, shallow and zero tillage practices on the yield of wheat, barley, oats and field beans grown in a sandy loam soil in the UK. The main effect of tillage showed that the zero tillage option significantly (***P < 0.001) reduced crop yields in four out of the five of the first crop years, with no significant effect in years two, six and eight and exceeded the yield of the other tillage treatments in year seven. The specific costs of the alternative tillage systems were estimated, from which the cost saving for zero tillage compared to deep tillage was c. £ 60 ha−1 (US$80 ha−1), which compensated for the overall loss in yield. There were no significant differences between the crop yields from the deep and shallow tillage treatments, with shallow tillage offering savings in operational costs of c. £ 30 ha−1 (US$ 40 ha−1). Overall, the controlled traffic farming system, where 30% of the field was trafficked, produced 4% greater crop yields (*P < 0.05), worth £ 39 ha−1 (US$53 ha−1) than standard tyre inflation pressures (STP). The estimated effect of reducing the trafficked area to 15$ 100 ha−1) compared to the STP system. The beneficial effect of low inflation pressure tyres (70 kPa and 80 kPa) on crop yields, for the deep tillage treatment, was significantly greater (*P < 0.05) than those of the standard tyre pressure system (100 kPa to 150 kPa) returning an average 3.9% additional crop yield over the period of the experiment worth £ 39 ha−1 (US$ 53 ha−1)

An economic appraisal of the effect of tire inflation pressure for alternative tillage systems on a silty clay loam soil

Compacting soil has an adverse effect on soil properties, decreases crop productivity, and subsequently reduces farm income. Low tire inflation pressure (LTP) help in managing soil compaction and protecting the soil environment; however, there is scant economic data available on LTP in US Midwest farming systems. Hence, a 3-year study investigated the effects of LTP, compared to tires inflated to the standard tire inflation pressure systems, on crop yield and farm economy for a typical maize/soybean rotation. The effect of the two tire inflation pressure systems was factorialized with three tillage systems: deep tillage (DT, 450 mm), shallow tillage (ST, 100 mm), and no-till systems. The results showed that LTP systems increased maize (Zea mays) yield by 4.51% (2017) and 2.70% (2018) and soybean (Glycine max) by 3.70% in 2018. Annual earnings for both 200- and 800-ha farms increased for all tillage systems with LTP tires based on a partial budget analysis. The payback periods for LTP tires were very short, ranging from 0.32 years for DT on an 800-ha farm to 1.18 years for ST on a 200-ha farm. The net present value of the higher returns with LTP tires was substantial, especially for the DT system. This study shows a strong economic benefit from investments in LTP tires on silty clay loam soils in the US Midwest

Genetic, abiotic and social influences on sex differentiation in cichlid fishes and the evolution of sequential hermaphroditism

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73799/1/j.1467-2979.2005.00184.x.pd