Healthy soil is Rob’s aim

Lauren CelenzaCountryman

Innovative and sustainable farming is what it’s all about at the Grylls’ farm in Bencubbin.

Rob Grylls has always had an eye on improving the soil on the family farm, which he and wife Lauren share with his parents, Jack and Ann.

The third generation farmer said that driving around the farm every day he noticed that where the soil was eroded the crop did not grow as well.

“If you lose organic matter, soils eventually become unproductive, ” he said. “On the sandy soils, if carbon is lost, soil becomes like beach sand, and on clay, soil becomes more like concrete.”

Wanting to improve the organic carbon of the soil, Rob decided to try compost.

Last year he trialled a mix of Custom Compost’s Balance MAP and granulated sulphate of ammonia down the tube.

This year at seeding Rob included 60kg per hectare of a one-to-one mix of Balance and Whitfert’s Whitstar which is MAP and sulphate of ammonia already blended.

“The Whitstar gave me five units of phosphorus, five units of nitrogen and three of sulphur which is the minimum requirement for a starter fertiliser in this area, ” he said.

Although most of the major nutrients come from the Whitstar, Rob said using Balance was for its biological value.

“Compost is more like a soil improver — it provides humus which is a microbial stimulant, ” he said. “I’ve also been using Guano Gold organic phosphorus fertiliser successfully on lupins and peas for three years and we have used lime at 1–2t/ha on most acidic sandy soils, which make up about a third of our property.”

Last year, Rob trialled the Balance-Whitstar mix over parts of his cereal crop, but decided to put it over the lot this year.

“You can’t really measure the benefits of increasing the microbial activity after one year, but the crop and its roots do look healthier, ” he said.

“I also trialled using a seed inoculant on the cereals which showed a big increase in root growth and microbial count.

“It will take about three years to turn around the soil’s health, and then we will really see the benefits.”

Rob said some chemicals could affect the soil’s microbial count.

“Group B herbicides, which are traditionally used before seeding, generally reduce the soils microbial count, ” he said.

“After a dry year like last they can also persist in the soil and that can be really detrimental to next years’ pastures.”

Rob has dropped group B herbicides out of his rotation, and is pretty happy with the result.

“I don’t have to clean out my boomspray as much when I go to spray the lupins and peas, ” he said.

Rob seeded 2600 hectares of crops, including wheat, barley, lupins, peas and triticale.

He has 1850 Merinos, of which 1400 ewes were mated this year.

“We got 1200 lambs — about 85 per cent — which is better than our average, ” he said. “The lambs are fit and strong and the ewes are fat and most of the farm is looking good.”

This year Rob also planted a fodder shrub trial to determine which varieties of saltbush, rhagodia and acacia suited the farm.

“It’s to see how well they perform because they have to survive being grazed and regrown, ” he said.

“The saltbush provides sheep with protein and minerals from deep in the soil profile. This year ewes which had saltbush wouldn’t touch mineral supplements, but the other ewes couldn’t get enough. The acacias will also produce large seeds in summer which the sheep should eat as well.”

Rob said the shrub alleys also protected the soils from wind erosion.

“If you get wind erosion, which we are prone to, you lose soil carbon at a rate of knots and that’s what I’m trying to build up, ” he said.

The fodder shrub rows are planted in straight lines using GPS guidance and spaced to suit the farm’s machinery.

“This way about 13 per cent of the paddock will have fodder shrubs that provide feed for the sheep and protection for the soil when the dry weather comes back, ” Rob said.

“I think this system would be a more sustainable way to present paddocks than the wide-open landscape we have now, especially with the way things are going with reduced rainfall.”

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