Consistently there have been two main questions:  “What fertiliser should I put on?”, and “What should I do to reduce greenhouse gas emissions and improve soil carbon levels so that I can meet demands from regional councils and prepare for future regulations?”

These are serious questions. The issues are complex and interrelated, and the answers certainly have significant implications for our future as farmers and the sustainability of our country.  If you sift through the science, talk with knowledgeable people and measure the right things, the issues become clearer.

The major concerns of regional councils seem to be leaching of nutrients into groundwater and waterways, and essentially they are talking about the abuse of superphosphate and urea.  The combination of high stocking rates and high soluble fertiliser use, particularly in cold, wet weather, leads to a situation where some leaching is inevitable.  Add to that the inadequate treatment and indiscriminate irrigation of effluent from the farm dairy or stand-off pads and it is no wonder councils are worried.

The other major concern is more a government one – the greenhouse gases methane and nitrous oxide.  Methane is belched by ruminants, and the message that is starting to be spread around is that we have to find a chemical drench or bolus that we can give to cows and sheep to reduce methane production in the rumen.  Terrific!

The other important greenhouse gas is nitrous oxide, which escapes from soil particularly in cold, wet weather when the soil is saturated or pugged.  It is worse when nitrogen has been used to boost grass growth.  The proposed solution?  You’ve guessed it – more chemicals in the form of nitrification inhibitors spread onto paddocks in autumn and winter at a cost of perhaps $250 per hectare.  Terrific!

We hear a lot about careful use of fertilisers, keeping them away from waterways, not topdressing or irrigating when heavy rain is coming, limiting grazing during winter and keeping stock on stand-off pads etc where urine can be collected rather than dumped in patches onto soil.  Good, sensible stuff.

We are also told that nitrogen leaching and nitrous oxide production is largely a urine patch problem.  What researchers don’t always tell us is that high-N urine is a high-N feed problem, which generally means urea-boosted grass. 

They don’t tell us that not using urea will roughly halve N leaching and gas production.   They don’t tell us that high carbohydrate, low-N pasture will dramatically reduce urine nitrogen, or that this type of feed also results in less methane being produced.

They will point to the fact that if dairy farmers don’t use nitrogen fertilisers their production will drop, and they assume that would be a bad thing.  How do they know?  They haven’t looked at the profitability of using slow-release fertilisers, stopping urea use, and reducing stock numbers to match feed available. 

Well, I have news for them.  By driving off the Six Laws of Best Farm Business Practice and measuring daily profit, a number of eCOGENT members have done just that, and they have found the result to be very worthwhile not just in terms of profit but also in stock health, reduced costs and reduced stress on them and their staff.  Applying the Six Laws makes it clear what fertiliser mixes to use to achieve profitability and environmental goals.  As a result they use less fossil fuel, have lower vet bills, and have better nutrient retention and increasing carbon in their soils.

I see it as an on-going nutrient cycle running from soil through plants, animals, and food to people. If we as farmers manage our share of the cycle well and seek to maximize profit, our experience at eCOGENT indicates that the result is quality food with less environmental damage.