with Brett Petersen
Kiwi Fertiliser & Golden Bay Dolomite
Soil can make available some of the nutrients required, substituting for applied fertiliser.
To provide top performance a soil should be composed of 45 per cent mineral 5 per cent organic matter and 50 per cent pore spaces, being occupied by 50 per cent air and 50 per cent water to provide the correct environment for the microbes.
The Albrecht system of soil fertility uses chemistry, (Ca and Mg) to affect soil physical structure which determines the environment for the biology.
Soil microbes interact with plant roots and minerals to release plant nutrients to provide nutrition to the plants.
Fertilisers need to be calculated to complement this natural process. This is demonstrated with a biological fertiliser program on a dairy farm, where production has shown an increase of .2kg of milk solids per cow per day with 50 per cent less nitrogen applied compared to traditional fertiliser practises.
Another dairy hill farm increased pasture production from 10.8tDM/ha to 16.2tDM/ha over five years and only applied 3kgN/ha.
As one farmer put it; ‘You can’t grow 23t/haDM if you are fertilising for 13’. Yes, that was his farm’s improvement, not to mention the increased quality, production, and profitability.
For cereal growing, soil scientists’ and agronomists’ calculations to determine nitrogen requirements to grow one tonne of wheat was 25kgN/ha, the calculation being, say 14 tonnes yield, minus N that was already in the soil, say 80 kgs/ha and supply the rest from applications of nitrogen fertiliser, (14x25=350-80=270 kgs N/ha).
In a wheat growing competition organised by the Methven A&P Association in the 2021-22 season, Springfield Estate grew a feed wheat crop that yielded 16.1t/ha. This is nearing world record levels. More significant than the yield was increased profitability. This yield was produced with half the normal nitrogen applications, with less fungicide, herbicide, no insecticide, and minimal cultivations.
The previous crop was a daikon radish seed crop direct drilled into a grass-seed/grazing field. The soil provided 66 per cent of the N and mineral requirements for the crop, with sufficient in the soil to not require applied nitrogen.
Over the last decade the farm has taken a biological approach and focused on resetting the balance of minerals, enhancing photosynthesis, carbon management and raising the microbiology levels in the soil.
This required studying, re-educating, and understanding of how soil and plants work, understanding the importance of biology, how it functions and the role of different microbes in the soil, how to support, feed and the management changes required, and to mitigate any harmful practices to soil and the biology.
All these practices were designed to enhance soil life and improve nutrient efficiency to provide resilience in the farming operation. The objective is to increase farm profit rather than spend most of it on fertilisers, therapeutics and other costs that take a back seat when the sciences of chemistry, biology and physics are correctly combined by using the Albrecht system of soil fertility and the manuals published by Kinsey Agricultural Services.
The manuals are in turn based on the figures produced from soil samples tested by Perry Agricultural Laboratory. At Kiwi Fertiliser, we religiously follow these practices with all our clients.
Many thanks to Don Hart of Springfield Estate.
The full version of this article is available at www.coastandcountrynews.co.nz