Make the microbes feel at home

“What the microbes want is to live in a nice house, but what they sometimes get is a harsh environment and poor resources.”

CSIRO Land and Water scientist Vadakattu Gupta likes to put a little flesh on the bones of soil research with the message that soil-living organisms (like all of us) need the right conditions under which to grow and multiply.

Why should we care? Well, says Dr Gupta, for one thing many of these organisms are the farmer’s friend — assisting in the release of nutrients from the soil, combating the effect of soil-borne diseases, and degrading herbicides.

Speaking to Mallee farmers he said, “You really do need to try and get a large microbial biomass in your mallee soils. Apart from anything else they help to hold nutrients in the topsoil where they are available to plants.

“There are also the rhizobia bacteria which assist with nitrogen fixation with medics and pulse crops.”

He said the inherent low fertility of mallee soils, containing low levels of microbial biomass and activity, was far removed from the plush house scenario.

Farmers should be providing the microbes with their preferred food source, carbon, by increasing stubble production through adequate fertiliser inputs, intensification of cropping and stubble retention. Stubble provides the added advantage of keeping the soil moist, a domicile option preferred by soil organisms if they are to multiply.