About 8 years ago MAF, Fonterra, and the fertiliser co-ops started wasting $10m on nitrogen research. I don’t know how far they got, but if it needs mitigating, nothing has changed. This approach is attempting to preserve the status quo and as such is irresponsible. A quick look at urea history shows us why business as usual is important for those businesses. 1979, the first shipment of 16,000 t into NZ. 2016, 560,000 t were imported, and 260,000 tonnes were manufactured locally. That’s 820,000 tonnes. Now that’s a $39m business to be protected!
2008 was a drought year, but a farm (NR) I was supervising increased production by 6%. We used 9kg/ha N. Most drought-affected farms and BOP focus farm decreased production by 15%. Eastern Bay of Plenty Focus Farm N usage was 191kg/ha. That is 21 times as much and for what? Grass growth was very similar with 12,900kg/ha on BOPff and 12,400 on NR's gravelly soil. In 2009, NR was up a further 12%; N was 36 units. BOPff was down 8% with 235 units of N. Pasture analysis N for NR in 2009 averaged 4.6%. So, what is the big deal about applying nitrogen? When N is applied, farmers see a visual difference, but that does not translate to quality. The cows need to eat more, but they can’t eat enough. Not to mention digestion problems as reduced cud-chewing allows undigested grass to pass through the digestive system. The increase in growth lasts for two grazing rounds, then there are two rounds with decreased growth. Nitrogen carries other nutrients out of the soil.
There are 74,000 tonnes of free nitrogen above every hectare. Most farmers miss out on this resource because their soil life cannot capture it. To access this N, conditions apply. Appropriate calcium and magnesium %; available phosphorus and iron; cobalt and molybdenum. It does not pay to turn the tap off, but gradual reduction works fine. Most (not all) dairy farms have too little Ca and Mg; too much P, adequate Fe; too little Co and plenty of Mo. Some of these nutrients are being applied directly to the animals and pastures. That short circuits the natural systems and costs more in the long run with a never-ending list of animal health and reproduction problems. To capitalise on free N, get a PAL soil test through a Kiwi Fertiliser representative. They are competent biological and soil fertility consultants expertly trained by Neal Kinsey and others.
Nitrogen can be sprayed on with buffering substances, usually fulvic acid. A carbon source such as biochar accompanies any solid fertiliser including nitrogen. If N is applied without C, bacteria, that have a C:N ratio of 5:1, have no choice but to consume soil organic matter to maintain that balance. Research shows that every kg of excess N causes the loss of 100 kgs of soil carbon.
Nitrate pollution of water, milk, land, pasture, animals, and humans are symptoms of a degraded environment. When are we going to stop doing what’s not working and apply some simple common sense that really works? Identify what drives profit, not production.
