Better soils with Brett Petersen Kiwi Fertiliser & Golden Bay Dolomite

The year of 2008 was a drought year, but a dairy farm I was running increased production by six per cent while using 9kg/ha N. Most drought-affected farms and a Bay of Plenty Focus Farm decreased production by 15 per cent.

The BOPFF’s N usage was 191kg/ha. That is 21 times as much, and for what? Pasture growth was 12,900kg/ha on BOPFF and 12,400 on ours. In 2009, our pasture was up a further 12 per cent; N was 36 units. BOPFF was down eight per cent with 235 units of N. Pasture analysis N for ours in 2009 averaged 4.6 per cent.

What is the big deal about reducing N? 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 of low DM pasture allows undigested grass to pass through their stomach’s system.

Another farm fertilised by Kiwi Fertiliser in Waikato was measured by DairyNZ. Measurements were pasture eaten on rolling country, which rose from 11,500kg/ha to 14,100kg/ha – an annual increase over three years of 7.5 per cent including the 2013 drought. Nor was it just about dry matter. Pasture quality and stock health both improved.

A hill dairy farm increased its pasture growth by almost 50 per cent in the five years 2008 to 2012 while ending up applying a total of 3kg/ha of synthetic N/ha in 2012. Pasture production went from less than 11,000 kg/ha to more than 16,000kg/ha of pasture grown. There is no doubt that gains can be made through means other than nitrogen.

Meanwhile, the nay-sayers claim many farms will take a financial hit by having to reduce their N input. That can either be a self-fulfilling prophecy, or a challenge to overcome. Kiwi Fertiliser now has more tools in its toolbox than 10 years ago. There are six nutrients required to fix free nitrogen from the air. Appropriate calcium and magnesium percent as measured on the base saturation. Available phosphate, iron, cobalt, and molybdenum. If Mg is deficient or excess, it will require up to 50 per cent more bagged nitrogen to get the same results. The microbes need Co and Mo to help them create nodules, but most farmers and growers do not apply enough. Some do not apply any.

This adds the third soil-science in addition to chemistry and physical structure; and that is biology. Microbiology is where the greatest gains will be made on farms that already have good soil physics and chemistry. We have the expertise and the products to build pasture production and animal health to the next level. For those that lack the chemistry and physics, these areas need to be addressed first. But to be fair, that is where Kiwi Fertiliser was 10 years ago without the extensive knowledge we have now and were still able to increase pasture production by substantial amounts, including during droughts. That also applies to the drought of 2020. We can not only increase pasture production, but also improve animal health including halving empty rates, and lowering somatic cell counts. The potential has just begun.