Select Harvests Field Day

The recent Select Harvests Field Day at the end of January 2017 saw a visit from Agroecologist and compost advocate Nicole Masters from New Zealand. As a guest of Australian Soil Management (ASM), Nicole shared her impressions of the trial data from Select Harvests 450 ha almond orchard west of Narrandera and the value of building healthy soils.

Part of the Waste Less, Recycle More five-year program facilitated by the Environment Protection Authority (NSW EPA), Australian Soil Management is already is delivering measurable benefits in paddocks across NSW.

EPA organics manager Amanda Kane attended the field day at Narrandera and expressed her delight with the outcomes of the compost trials on the almond orchard site.

“Almost $800 million has been allocated to the Waste Less Recycle More program with Carbon Mate from Wagga Wagga being granted almost $1 million to expand their existing composting facility at the Gregadoo site. It is heartening to see their product being part of these extensive trials and demonstrating the links between green waste, recycling and composting then the return of those materials to where we grow food,” she explained.

In May 2015, eight tonnes of compost per hectare was distributed on either side of almond trees over ten hectares, located a metre from the trunks adjacent to the drip lines. The compost was supplied by Carbon Mate at Wagga Wagga. Ms Masters used her extensive knowledge to explain the improvements.

“Prior to spreading the compost, the Organic Matter was measured at 0.2% at 30cms. When measured again last week that percentage had risen to 0.9% indicating soil population activity literally taking it deeper into the soil. The carbon percentage altered from 0.13% at 30cm in May to 0.52% in the seven months since application.” 

“Mycorrhizal fungi are vital for healthy soils and yet fungicides are liberally applied in situations where having balanced soil populations would prevent (fungal) infestations in the first place. To demonstrate how powerful and important soil fungi are, the Swiss government is literally spraying them out to stabilise hillsides and prevent slides; the filaments of the fungi hold all the soil components together which is what naturally happens in highly vegetated areas.”

Peter Reynolds, Technical Officer with Select Harvests said he was surprised at how quickly positive changes had been created using compost. “During winter, the soil temperature was one degree warmer and feeder roots were found in the compost close to the surface of the soil. I haven’t ever seen that happen before,” he said.

“We realise these sandy soils are difficult to work with and building greater capacity to hold moisture and generate nutrient efficiency will take time, but I am happily surprised to see how quickly this regime has made measurable improvements,” Peter went on to say.

Greg Bender, former program coordinator for the Grains Research Development Corporation managing soil biology, pasture breeding and pulse breeding projects, has overseen these trials using compost. “We know compost will benefit any situation however we need better engineering to ensure the compost is delivered at depth instead of being broadcast when only the top 10cm of soil benefits.”

“The deep banding machine from Compost Matters delivers the material up to a depth of 700mm in the root zones so plants have immediate access to nutrients. This means less is required to achieve more effective results for broad-acre, horticulture, viticulture, market gardens, pastures and orchards. This is the next big step in regenerating flogged soils and ensuring continuous production of nutrient-rich foods,” Mr Bender added.

Ms Masters advocates the frequent use of a refractometer to accurately measure the Brix levels in plant tissues. “Insects don’t have a pancreas so that’s why they are repelled by plants with high Brix levels and will seek out plants which are weaker and have lower sugar in their systems. Ideally, almonds should be at 16 percent.”

“Almonds are reliant on mycorrhizal fungi as the filaments create 1,000 times more surface area to call for, and provide, minerals, water and other nutrients to each tree's roots. The same applies to any plant community and using compost to enable the expansion of root systems is evident here, even in this sandy soil,” she concluded.

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