Conference Papers

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7616

Browse

Author: search.filters.author.Davies CEHas files: Yes

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Characterization traffic induced compaction in controlled traffic farming (CTF) and random traffic farming (RTF) - A multivariate approach
    Raveendrakumaran B; Grafton MC; Jeyakumar P; Bishop P; Davies CE; Horne, D; Singh, R
    A field scale experiment was carried out in Pukekohe in 2020 under an annual grass crop season to characterize the subsoil compaction in controlled traffic farming (CTF) and random traffic farming systems (RTF). Soil penetration resistance (PR) measurements were taken in each field using a cone penetrometer fitted with a 100 mm2 60° top angle cone. Multivariate analysis was performed to identify penetration resistance by depth through cluster analysis and principal component analysis (PCA). Repeated measures ANOVA was performed on the penetration data using the mixed model procedure to determine the treatment effects. In RTF, the penetrometer values increased more rapidly with depth resulting in higher values being recorded from 20cm compared to CTF. In contrast, it was greater in CTF than in RTF at the subsurface (55-60cm). The differences in PR declined beyond 55cm depth at both sites. All depths showed that differences in soil PR were most apparent in the 5-40cm depth, with significant differences between CTF and RTF (P<0.0001). This shows that traffic management at both CTF and RTF sites caused significant changes in the 5-40cm depth. However, there were no differences in PR between CTF and RTF below 40cm and at 0-5cm depth (P >0.05) showing that the soil layers were homogeneous in both systems beyond 40cm depth. The propagation of subsurface compaction was identified at the deeper layer (40-60cm) in CTF systems whereas it was identified from shallower depths (25-55cm) in RTF system.
  • Thumbnail Image
    Item
    FEASIBILITY STUDY, EXTENDING THE SWATH WIDTH OF TOPDRESSING AIRCRAFT TO REDUCE STRIPING OF FERTILISER MIXES
    (Massey University) Brown HA; Grafton MCE; Davies CE; Currie, LD; Christensen, CL
    Fertiliser mixes of magnesium oxide coated urea and super phosphate require high application rates 250kg/ha - 500kg/ha. These rates are inclined to clog spreaders reducing their efficiency and compromising operational safety. As a result, the current spreader design is, not fitted for these rates. The swath width from a Cresco 08-600 without a spreader is only 12m wide, meaning many passes are required to cover a field. The mixture also tends to segregate which leads to striping. A new method of spreading fertilizer, which provides a wider swath width and an even distribution, is required. This method must be able to meet the CAA requirements for topdressing safety, minimise segregation in fertiliser mixtures and preferably should be applicable to most bulk fertilizers in common use; the method must not add any significant weight to the aircraft that would decrease its operating capacity. The feasibility of developing a means of initiating spreading of bulk fertilisers from topdressing aircraft hoppers from regions outside of the influence of the prop wash are investigated. If feasible, the system should be able to apply fertiliser across a 40m swath width at the target application rate, in a single pass. This would reduce flight time and improve the distribution pattern leading to reduced operating costs and higher crop yield. This preliminary report suggests that it is mathematically possible to widen the swath width of the Cresco 08-600 to 40m at an application rate of 350kg/ha by means of a screw conveyor transporting and evenly releasing fertiliser along the length of the wing up until the dihedral is reached. The next stage in this project will be to design the screw conveyor system and test it on the ground to see its limitations and potential safety concerns.