Diversity the key for farming

Christine Jones explains how Plantain has a fibrous tap root that's
great for breaking up compacted soils.
Christine Jones explains how Plantain has a fibrous tap root that's great for breaking up compacted soils.

More than fifty Central West farmers aiming to improve their pasture and soil management were recently told: Green is good, diverse green is better but year around, diverse green is best.

Soil scientist, Dr Christine Jones recently addressed the farmers at an oversubscribed field day on the property Liscombe Pools, near Millamolong, Canowindra.

In recent years producers have been working with Dr Jones’ research on soil science to find new ways to regenerate topsoil, enhance the nutrient density of food, hydrate the landscape and increase the profitability of agriculture.

“These things can all be resolved by focussing on one simple and well-known process … photosynthesis,” Dr Jones said.

She explained how producers worldwide are achieving large improvements in soil health in a relatively short time through multi species cropping which supports year-round green growth.

Canowindra farmer Rob Watt is a big fan of Dr Jones’ research and has successfully developed his own pasture cropping system.

“You need to have more than 8 different types of plants in the one paddock to get the results. I have sown cereals (oats, barley, cereal rye, triticale) along with forage brassicas and legumes (turnips, arrow-leaf, clover, sub clover, vetch). This is in addition to what was already in the paddock (lucerne, phalaris, ryegrass) and the native grasses (microlaena, paspalidium, wallaby grass),” said Watt.

“My paddocks carry ewes and lambs through the winter. Last year I harvested the cereals for replacement seed. This year I grazed it right out, but with the current rain, it’s all growing again. The plants seem to help each other stay greener for longer,” he said.

“Infiltration, water-holding capacity and drought resilience are improved when bare fallows and low diversity pastures are enhanced with multi-species additions. This improvement has been particularly evident in lower rainfall regions and in dry years,” said Dr Jones.

“It’s all to do with what was happening below the ground. It’s about soil microbes and how they interact with growing roots. Deep rooted perennial plants have never been more important to have in our landscape,” explained earth scientist and Canowindra producer, Andrew Wooldridge.

“Soil function is strongly influenced by its structure. In order for soil to be well structured, it must be living. Life in the soil provides the glues and gums that enable soil particles to stick together into pea-sized lumps called aggregates. The spaces between the aggregates allow moisture to infiltrate more easily. Moisture absorbed into soil aggregates is protected from evaporation, so that soil remains moister for longer after rain or irrigation. Well-structured soils are also less prone to erosion and compaction and function more effectively as bio-filters. All of this can improve farm productivity and profit,” Dr Jones said.

“Over the last 150 years, many of the world’s prime agricultural soils have lost between 30% and 75% of their carbon, adding billions of tonnes of CO2 to the atmosphere. Losses of soil carbon significantly reduce the productive potential of the land and the profitability of farming. Soil degradation has intensified in recent decades, with around 30% of the world’s cropland abandoned in the last 40 years due to soil decline. With the global population predicted to peak close to 10 billion by 2050, the need for world-wide soil restoration has never been more pressing,” Dr Jones said.

“If all agricultural, garden and public lands were a net sink for carbon we could easily drawdown sufficient CO2 to counter emissions from the burning of fossil fuels.

Everyone benefits when soils are a net carbon sink. Through our food choices and farming and gardening practices we all have the opportunity to influence how soil is managed. Profitable agriculture, nutrient dense food, clean water and vibrant communities can be ours … if that is what we choose.”

Dr Christine Jones was invited to the Central West by Scott Hickman as part of Mid Lachlan Landcare’s ‘Growing the Grazing Revolution’ program.