Better soils with Brett Petersen Kiwi Fertiliser & Golden Bay Dolomite

Over the coming months, Brett will share 40 facts about fertiliser that will help optimise your soil. Here are the first 10.

Kiwi Fertiliser can show you how increase profitability while growing your soils. Human and humus are the same root word, “of and from the soil.”

1 A comprehensive soil test should be completed annually to determine what nutrients needs to be applied to the soil to maintain fertility balance. Kiwi Fertiliser recommend soil analyses by Perry Agricultural laboratories (PAL).

2 The soil is the plants stomach; please respect it. Human health reflects soil health.

3 Some chemical fertilisers kill microbes causing imbalances. Superphosphate and urea are deadly to beneficial soil fungi. Nitrogen is the only major plant nutrient that you can grow yourself. Watch salt and ammonia levels, insist on applying only fertilisers which do the least damage to soil life and plant roots – nitrogen input can be reduced over time by promoting soil biology.

4 Ninety-five per cent of plant yield comes from the atmosphere, only five per cent comes from the soil.

5 Fertiliser programmes must be based around the calcium content of your soil. If calcium base saturation is below 60 per cent, you will virtually have to purchase fertiliser ad infinitum.

6 The correct base saturation figures from PAL tests for soils are: calcium 65-70 per cent, magnesium 10-12 per cent, potassium three to five per cent for pastures, seven to 7.5 per cent for trees, sodium 0.5-1.5 per cent. Many NZ soils are well below these figures. Once these conditions have been met, fertiliser requirements will drop substantially. Do not expect to address trace elements until those conditions are met. Soil pH will auto-correct to about 6.3 or 6.4 when the above conditions are fulfilled.

7 It is extremely important to get calcium levels up. Calcium is responsible for carrying other minerals into the plant but too much calcium can tie up other nutrients and cause deficiencies. Soil testing with a reputable lab is the only way to effectively measure base saturation and calcium levels.

8 Calcium and boron are synergists, so lime is more effective with boron added. Boron, along with copper, selenium, and cobalt, is commonly deficient in New Zealand soils.

9 Lime to correct calcium, not to “correct” pH, Calcium: improves root development, enhances microbial activity, increases the transport of minerals, is the vehicle that moves minerals into plants, improves soil structure, acts as a secondary messenger, improves plant health and disease resistance, is required for cell walls (pectin), enhances the rate of protein synthesis, serves as a weed indicator.

10 Dolomite is highly rated for its calcium and magnesium content; magnesium is found at the centre of the chlorophyll molecule, the plants light-harvesting, energy-producing centre. Magnesium also plays an important role in the production of oils and proteins, and energy metabolism.