Better soils with Brett Petersen Kiwi Fertiliser & Golden Bay Dolomite

Some published papers claim the ‘Albrecht’ system of soil fertility does not work.

A better explanation is the authors of the papers and their publishers do not know how to make it work. When it is used after all else has failed, there is no going back.

This article is about pH. How the pH is constructed is more important than the pH itself. It concerns an example near Brawley, California, just north of Mexico and close to the Colorado River, which has 800ppm of sodium (one tonne of Na per acre-foot of water).

Annual rainfall is 50mm. Crops do not grow without irrigation.

The owners had trouble growing crops for 40 years, and no wonder as the calcium was 46 per cent, magnesium 30.3 per cent, potassium 3 per cent and sodium 17 per cent.

pH was 8.1. In this valley, you are not going to get to 6.

Desired base saturation levels in this case are 80, 10, 5 and 3 per cent respectively.

Although these levels are extremely deficient or excessive, these figures are very common in Imperial Valley.

The principles for correction are the same for all soils, although the desired range may change.

A US example

The crop grown was sugar beet. This part of the property did not perform at all. Recommendations by an employee of Helena Chemical Co. who follows the Albrecht system included 9000kg/ha of lime.

Potassium was also added along with trace elements, but the main thrust is to reduce the excesses, being sodium and magnesium. Lime was incorporated into the soil and all broke down in 18 months. At that point, another soil test was taken, and the results were calcium 62 per cent, magnesuim 24.5 per cent, potassium 4 per cent, and sodium 6.6 per cent.

The difference is an increase in calcium of 16 per cent and a decrease of 16.2 per cent for magnesium and sodium.

This is exactly what was predicted would happen. pH had hardly moved from 8.1 to 7.9. The calcium increase made little difference to pH as magnesium and sodium have a greater effect on pH than calcium.

The role of PH

Many soils researchers get caught up in the pH trap. We want to know what the pH is to inform us how available the trace elements are going to be to the plant.

But the calcium:magnesium percentage is the critical factor. The soil mechanics are correlated to this per cent.

Calcium pushes the soil particles apart, increasing pore spaces and magnesium pulls particles together.

In these high total exchange capacity soils there is a high percentage of magnesium (a soil ‘tightener’) which makes it hard to leach the sodium out.

Good drainage is needed to accomplish the removal of sodium.

Balance is key

It would be great to teach our professors the importance of knowing the TEC's, calcium:magnesium percentage and how they affect the real-world farming situation.

An 80:10 per cent is appropriate for high TEC soils, but a 60:20 per cent is more appropriate for low TEC soils.

These figures relate to a PAL soil audit and are not relevant to other soil tests. If we could reach and teach everyone the importance of balanced soils, the production of our soils would skyrocket.

Proper balance and nutrition have the potential to reduce hunger and most health problems.

The crop looked extraordinary as the sugar beet closed the metre-wide furrows for the first time in 40 years.