Base Saturation
Under our current system of soil fertility, we are being encouraged to under-fertilise. This state has existed for many years, but the degree of under fertilising is getting worse. Applying so called maintenance levels of nutrients is not even ensuring soil fertility is static; it is declining.
Base saturation (BS) is simply the percentage of exchangeable cations. Cations are the positively charged soil fertility elements. BS is used to identify and measure the %, not ratios of each cation to determine the soils’ available relative mineral makeup.
Total Exchange Capacity (TEC) is the sum of the total exchangeable cations. A light soil (eg. Volcanic) having a smaller sum than heavy, alluvial silt loam. The balance of cations (positively charged elements) determines soil structure, nutrient holding capacity, and fertiliser requirement for optimum production. Economic decisions can then easily be made to prioritise fertiliser applications. Some cations are: calcium, magnesium, potassium, sodium, manganese, cobalt, copper, iron, zinc, hydrogen, and ammonium.
What we try to achieve (according to a Perry Agricultural Lab soil test), is calcium about 68%, magnesium 10-12%, potassium 2-5%, sodium 0.5-3%, hydrogen 10-15%, and other bases to be about 5%. Don’t try to fit these numbers around another test; it will not work. Most laboratoties appear to only work with cation exchange capacity (CEC), not total exchange capacity.
If the cation balance is close to this ideal, we will have good soil structure, oxygen content, moisture movement and retention, drainage, maximum crop and pasture production and quality. All elements work together synergistically without antagonism, with pH being ideally constructed. Pasture and crop palatability and consequently, animal performance will all excel.
Practical considerations
In the short term, balancing the BS can be an expensive exercise. The alternative is to put on fertiliser to get your crop or pasture through the season.
Remember, chemical agriculture is a self-serving, input-driven system. You are advised to apply an unbalanced fertiliser to an unbalanced soil to sustain a state of imbalance, which will then require constant chemical intervention. After 20 years of doing that, the chances are you will be no better of in year 20, than you were in year one. Many farmers are complaining they are worse off. (This is a result of focussing on chemistry and chemical inputs, when in fact, soils are biologically driven.)
Soil balancing will require extra fertiliser. For some, the way to approach that is do a portion of the farm at a time. Hill farmers need to look at their flats first. Other farmers need to consider their silage paddocks, crop paddocks or parts of the property not doing so well.
Over time your farm performance will increase, while eventually, your fertiliser applications will decrease. The point at which the fertiliser spend will decrease, depends on how long it takes to reach that balanced plateau. Once there, it is plain sailing down the other side. What happens, is the correct chemical inputs alter the soil's physical properties, creating a better environment for biology to flourish.
The system we use at Kiwi Fertiliser is used and proven in 75 countres around the world. This method has produced a world record yield of wheat in Germany; best quantity and quality wheat in NZ; 37-42t+/ha maize silage in USA; best quality and quantity raspberries in USA; best quality and quantity bananas in Guatemala and South Africa; the best performing horse stables in South Africa; 20t+/ha of Lucerne all over the world, and growers being paid US$19/kg (2018) for their high yielding grapes by wineries in California, to name just a few successes.
