Oils ain’t oils and composts ain’t composts according to Nicole Masters, permaculturalist and specialised compost maker from New Zealand. She was the guest of Australian Soil Management reading trial data from Select Harvest’s 450 ha almond orchard west of Narrandera.
In May 2015, eight tonnes of compost per hectare was distributed on either side of almond trees to a height of 15cm by 10cm wide over ten hectares and located a metre from the trunks adjacent to the drip lines. The compost was supplied by Carbon Mate at Wagga Wagga and the project funded by the NSW Environmental Protection Authority’s (EPA) Waste Less Recycle More program. 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”.
“Mychorrizal 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 Harvest 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”, he said.
Greg Bender, former program co-ordinator 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”, she explained. “Ideally, almonds should be at 16 per cent”.
“Almonds are reliant on mychorrizal 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.