Background

Cell grazing changes the focus of a grazing farm operation from raising animals to managing grasslands. The health of the land must be the priority, as in poor conditions productivity of the farm will be reduced. The most common style of grazing is continuous, where animals are left in an area for long periods of time, often the entire year and eat the grass as it begins to grow back. This results in more stress on the plant and hampered regrowth, eventually resulting in a loss of biodiversity of grasses.

Cell grazing is a time-control grazing method, however it differs from other time-control techniques such as block or strip grazing in that it has a holistic focus. The focus of cell grazing is on sustainability and optimising profit, rather than on maximising plant and animal growth. Holistic management is a whole farm planning method with the aim to deliver successfully on the triple bottom line, sustainable environmental, economic and social outcomes. Cell grazing essentially aims to maximise the harvest of sunlight, by implementing the following principals [1]:

With the goal to [1]:

Pioneers such as Allan Savory have been advocating the benefits of holistic management, and educating others on its implementation for over 50 years. He believes that desertification of land can be reversed by running more livestock, rather than the conventional response to run less or completely remove the animals and rest the land. This does not prepare the land for recovery though; when it rains the water simply runs off the dry bare land. If livestock are used correctly they can have a beneficial effect as they create many small divots in the ground, where water can soak in, and fertilise the soil with their dung.

There are many examples of people using this type of holistic management on their land and seeing real improvements. Almost all of the graziers who have won Australian Farmers of the Year awards since 2007 have described cell grazing as the core of their farm plan [2]. As an example, in a low rainfall area of South Australia, one grazier has gone from a ground cover of less than 50% to 70-80% in just 7 years of using cell grazing [3]. This increased ground cover means that with only 10mm of rain the paddocks produce feed, when previously the water just ran away. For scientific analysis of cell grazing see T. McCosker’s report [1].

Soil is the third largest sink of carbon in existence, after oceans and geologic sinks [4], so increasing the amount of carbon in the soil could present a safe and simple way to sequester carbon. Many of our modern farming practises are having the opposite effect of losing soil carbon, which reduces the productivity of the land, requiring more inputs to maintain fertility. The most effective way to increase the amount of soil carbon is to ensure that there is plant growth in the soil at all times [4]. Perennial grasses with good coverage and animals that are involved in the grasses life cycle have the potential to take carbon out of the air and store it in the soil.

The factors that make cell grazing a less attractive option than continuous grazing are, access to water, more fencing and increased time spent herding animals. Through smart layout of the cells it is possible to reduce the number of watering points required. The cost of fencing these additional smaller paddocks is significant, and therefore a major drawback of cell grazing. There is also additional labour time associated with moving animals frequently, requiring the animals to be rounded up and herded through gates across the property.

OpenFence

OpenFence’s aim is to make it easier for graziers to focus on the management of their land and reduce the costs and labour associated with Cell Grazing techniques. Fences are expensive to install and maintain, and aren’t able to change with the variable nature of feed quality and quantity. Moving livestock frequently to fresh pasture, through gates, is time consuming and difficult. OpenFence aims to remove these inhibiting factors of Cell Grazing through the flexible nature of digitally defined boundaries.

Livestock such as cattle have been successfully trained to associate audio alerts with a boundary, when an electric shock was used as part of the training process. There are many papers on the subject by the US Department of Agriculture’s, Dean Anderson [5]. When no electric stimulation was used in training, as studied by Butler et al., there was a limited reaction by dairy cows to a variety of sounds [6].

OpenFence will build upon research performed over the past few decades to create a complete engineered solution, taking it from a research device to a device that is manufacturable and usable for extended periods in the field. As this is primarily an electrical engineering project, the objectives will focus on the design of the electronic device and associated software, rather than on the animal behaviour outcomes.

The solution should be a small and lightweight collar, with self contained charging and energy storage, variable alerts of sound and electric stimulation, and wireless low powered communications. Each collar has a GPS allowing the software to determine if the animal is within the boundary, approaching the boundary or outside the boundary. The devices will be weather-proof and able to withstand harsh outdoor conditions. Keeping the device cost to a minimum will be a key goal.

The collars will be paired with a repeater station in the field, which will allow the collars to use short-range telemetry, reducing their power consumption. The repeater station will also contain its own battery supply and solar panel. This will upload the data it receives from the collar devices to the internet, and download any changes to the fence locations to the collars. A good spot to place the repeater would be near watering points as the animals will always come back to this area through the day, allowing the transfer of data if they had been out of range.

The Management Software will run though a web application, which allows the simple placement of fences, tracking of the herd, and viewing of logged GPS waypoints for individual or multiple animals. The benefit of using a web-based application is that it will allow the farmer to check and set the fences from a mobile device in the field or on a computer at home. This however does not mean that the system can be used completely remotely, as the health of the animals, access to water and amount of feed must be monitored by an experienced farmer on the ground.

The name OpenFence was chosen because all software and hardware that is being developed will be made available as Open Source, under GNU GPL v3.

References

[1] T. McCosker, “Cell Grazing – the first 10 years in Australia”, 2000. Available: http://bit.ly/1o8RxeB

[2] M. Kiely. (2011, Dec.). “Grazing Systems don’t work: Tell the Farmer of the Year”. Carbon Farmers of Australia. [Online]. Available: http://www.carbonfarmersofaustralia.com.au/carbon-farmers-of-australia-blog/grazing_systems_don-t_work_tell_the_farmer_of_the_year_

[3] Neil Sleep. “Cell Grazing System in Low Rainfall Areas”. Ag Excellence Alliance. Available: http://agex.org.au/media/cell-grazing-system-in-low-rainfall-areas/

[4] M. Bell, D. Lawrence. “Soil carbon sequestration – myths and mysteries”, 2009. The State of Queensland, Department of Primary Industries and Fisheries. Available:
https://www.daf.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/soil-carbon-sequestration

[5] D. Anderson. “Virtual fencing – past, present and future”, The Rangeland Journal, Vol.29, 2007, pp. 65-78. Available: http://jornada.nmsu.edu/bibliography/07-018.pdf

[6] Z. Butler, P. Corke, R. Peterson, and D. Rus, “Virtual Fences for Controlling Cows”, Proc. IEEE International Conf. on Robotics and Automation, Vol.5, 2004, pp.4429-4436.