Craig Baillie

Evaluating On-Farm Energy Performance in Agriculture

Abstract On-farm energy efficiency is becoming increasingly important in the context of rising energy costs and concerns over greenhouse gas (GHG) emissions. Energy audits are a crucial part of the overall energy and environmental management process. In this paper, the results of six on-farm energy audits are presented. It is shown that energy uses for these farms varied significantly, ranging from 1.29 GJ/ha for dryland sorghum production to 43.06 GJ/ha for avocado production. In some cases, nearly 80% of operational energy was expended on water harvesting and irrigation. The research shows that there is currently a strong need to develop standardised energy assessments and reporting protocols so that effective and widespread energy audits in agriculture can take place. It is further suggested that an energy audit in agriculture in the future may best start from irrigation, as it also consumes a considerable proportion of on-farm energy cost.

Spot Spraying Reduces Herbicide Concentrations in Runoff

Rainfall simulator trials were conducted on sugar cane paddocks across dry-tropical and subtropical Queensland, Australia, to examine the potential for spot spraying to reduce herbicide losses in runoff. Recommended rates of the herbicides glyphosate, 2,4-D, fluoroxypyr, atrazine, and diuron were sprayed onto 0, 20, 40, 50, 70, or 100% of the area of runoff plots. Simulated rainfall was applied 2 days after spraying to induce runoff at one plant cane and three ratoon crop sites. Over 50% of all herbicides were transported in the dissolved phase of runoff, regardless of the herbicides sediment-water partition coefficient. For most sites and herbicides, runoff herbicide concentrations decreased with decreasing spray coverage and with decreasing herbicide load in the soil and cane residues. Importantly, sites with higher infiltration prior to runoff and lower total runoff had lower runoff herbicide concentrations.

Development and evaluation of a prototype precision spot spray system using image analysis to target guinea grass in sugarcane

Abstract Herbicide usage in weed control represents a significant economic cost and environmental risk in Australian sugarcane production. Weed spot spraying has potential to increase sugarcane production while reducing chemical usage and environmentally damaging runoff. However, weed spot spraying is traditionally a laborious manual task. This paper reports on a precision machine vision system that was developed to automatically identify and target the difficult to control weed Panicum spp. (Guinea Grass) in sugarcane crops. The infield machine vision system comprised a camera and artificial illumination to enable day and night trials. Image analysis algorithms were developed to discriminate Guinea Grass and sugarcane based on colour and textural differences between the species. A positive weed identification from the image analysis activated solenoid-controlled spray nozzles. Evaluations of the system in a sugarcane crop established that the image analysis algorithm parameters required frequent recalibration during the day but that the requirement for recalibration was reduced at night with constant artificial illumination. The algorithm was only effective at detecting mature Guinea Grass. The developed technology is considered a viable alternative to manual spot spraying of mature Guinea Grass in sugarcane at night. A cost benefit analysis of the new weed control system indicated potential grower savings of

Reducing energy use and costs in agriculture

170/ha by adopting the technology.

A case study for biogas generation from covered anaerobic ponds treating abattoir wastewater: Investigation of pond performance and potential biogas production

Agriculture and the related primary industry is an increasingly energy demanding sector. Energy is needed to different extent in all the stages of the agri-food chain. In many cases, energy cost may represent a significant proportion of the total agricultural production cost, including the cost of manufacturing and transportation of various chemicals and fertilisers. A modified and standardized energy analysis and benchmarking process is described in this paper. It is shown that energy use in agriculture varies considerably, depending on the cropping enterprise and the farming systems. Opportunities to reduce energy use and costs and greenhouse gas emissions in agriculture are discussed.