Expert opinion

Individual weather data key to reducing fertiliser losses into lakes

Farmers are notoriously keen meteorologists, but standard weather reports are not exactly known for pinpoint accuracy. This can be problematic when it comes to fertiliser application – particularly when missing the mark means contributing to a major environmental problem.

Farmers need to know how much moisture is present on their land in order to make good growing decisions. However, weather reports providing widely gathered and aggregated information are just not specific enough to be useful at an individual field level.

The problem is significant for producers in Southwestern Ontario, Canada’s most southern point, where nutrient run-off from farmland has been cited as the main cause of annual, toxic algae blooms in Lake Erie – the warmest and shallowest of the Great Lakes.

These algae blooms emerge each summer to threaten human health through contaminated drinking water, as well as the health of the lake’s ecosystem. Needless to say, there’s a lot of pressure on farmers to find solutions, whether it be through volunteer action or enforced legislation (the potential for the latter looming ever larger).

Detailed weather data

Technology and “Four R” nutrient management – right rate, time, place, and amount – offer some highly customisable solutions.

Several agronomy businesses in Canada’s most southern counties, for example, have started offering a minutely scaled, up-to-the-minute rainfall and temperature data service to help farmers manage potential fertiliser run-off problems – and get more efficient in the process.

A sign waning for blue-green algae is see by the shore of Lake Erie on Put-In-Bay on South Bass Island, Ohio
A sign waning for blue-green algae is see by the shore of Lake Erie on Put-In-Bay on South Bass Island, Ohio. Photo credit: Alamy Stock Photo

The AGGrower dashboard, as it’s called, makes use of 280 strategically placed weather stations to map temperature and rainfall at the acre level. Users can access real-time data about specific parts of their fields, and adjust their growing decision accordingly.

Programs such as the AGGrower Dashboard are being used in conjunction with other precision technologies and techniques, such as GPS and variable rate spreaders, to minimise the amount of fertiliser escaping to Davy Jones’s locker.

Mapping soil nutrient levels

Interest in cover crops, too, also appears to be increasing – at least in the Canadian part of the Lake Erie watershed – as is the focus on updating and more precisely mapping soil nutrient levels. And this is likely a good thing.

The threat of legislation looms, you see. Voluntary measures taken by farmers to reduce run-off have been deemed “insufficient” by the international body responsible for advising Canadian and American governments and official government action is looking more likely.

What proposed legislation would entail, however, remains to be seen.