Presenter - Colin Seis from Central Tablelands of NSW
Forum held at Bellarine Landcare, 30th March 2022.
Written By Andrew Lang
Colin is a third-generation farmer on the 800-ha property, Winona, in central NSW. It is country with some rocky tops with remnant native trees, and quite productive granitic sandy-clay-loam soils (pH about 5.5-6) across the rest of the property. Rainfall is about 600 mm with this spread relatively evenly through the year. About 500 acres is sown annually to ‘pasture crop’.
Much of the farm had been cropped continuously since the late 1930s. Colin took over in the early 1970s and ran it along a similar line with declining profits. Soil structure was gone, and acidity was increasing, salinity was becoming a problem, and native trees were suffering dieback. At the same time, the cost of fertiliser and machinery were on the increase. A devastating fire in 1979 killed 75% of the sheep, 50 km of fencing, and all machinery, housing, sheds and yards were gone, and there was no money in the bank. This presented a challenge. From 1980 he stopped all use of fertiliser on pastures, ceased the use of pesticides and began rotational grazing, while lambing twice every 18 months or less to rebuild sheep numbers.
By default, he discovered that what grew back in the pastures had some fraction of native pastures, and his management encouraged this fraction to increase. At no point did he sow native grass seed. He says that the previous decades of cropping had involved weed control by traditional cultivation, so the seed store in the cropping ground was presumably occasionally replenished with new native grassland species seed.
Colin detailed the breakdown of plant species into:
C3 grasses (wallaby and spear grasses, microlaena, phalaris, poas, silver grass) and crop species (wheat, oats, barley). These are winter growing and not tolerant of heat over 30 C. About 95% of plants around the world demonstrate this C3 photosynthesis pathway.
C4 grasses (windmill grass, kangaroo grass, red grass, Rhodes grass, paspalum, green panic) and cereals species (maize, millet, sorghum). These have a high water use but are tolerant of heat, and so are summer growing. Only about 1% of plants demonstrate the C4 photosynthesis pathway, with many of these being found in Australia, constituting the dominant Australian grassland species.
He says there are about 1080 grassland species across Australia including herbs and forbs, and he now claims to have about 50-60 on his property, dominating his pastures.
By 1993, he began to experiment in early winter with sowing crops (usually oats) using narrow points directly into the dormant and grazed down C4-type native grass pastures. By the time the grasses came out of dormancy the oats were high enough so that they could be harvested cleanly. No burning is done, and full pasture ground cover is retained. No pesticides have been used for over 30 years and the populations of predatory insects are very high – most noticeably spiders and ladybirds. He claims to have no problem with pests like red-legged earth mites.
Colin harvests the pasture crop and then cleans the grass seed out of the cereal seed and sells about 2 tonnes of cleaned grass seed a year, both awn and non-awn types. This includes Arm grass (brachiaria milliformis), Warrego (Paspalidum jubiflorum), Red grass (Bothriochloa macra), Cotton panic (Digitaria brownie).
The property is divided into about 75 paddocks mostly of 10-20 ha in area. The sheep are combined into a large mob of 2500 adults and 1500 weaners (under 1 yo) and graze any paddock for 2-3 days or until the pasture is about 50 mm high. The grazed paddock is then spelled for 3-4 months to allow a full recovery. Colin claims this means plant roots go far deeper and nutrient is greatly recycled. He strives for full ground cover and uses trampling to achieve nutrient cycling of crop stalks and to prepare pastures for pasture cropping.
Around 2010 he developed an alternative to sowing a single cereal, which was to sow a multi-species mix, including oats, forage brassica, field peas, turnip, daikon radish and vetch. These can be harvested all at once and the mix used for resowing. The property hosted a trial of 228 lambs grazing on only barley and 228 on this multi-species mix. Over the 57-day period, lambs grazing the mix grew at twice the rate, putting on 300 gm/head/day to achieve a 17 kg gain, versus lambs on the barley putting on 149 gm/head/day to achieve a 8.5 kg gain.
Colin claims to have not used fertiliser on pastures for 35 years though does use a relatively lower rate of fertiliser when pasture cropping, using a modified air seeder. He is prepared to use a selective herbicide like Basta to surgically control weed plants, but mainly relies on having a full soil cover, including a litter of trodden plant stems. Overall, any general use of herbicides ceased about 25 years ago.
He advocates the idea of a multi-layer enterprise with compatible enterprises, so he produces fine wool, stud merino rams, working dogs, sale sheep (mostly finished male hoggets) and cleaned graded native grass seed.
Colin claims one major benefit of his management is the improved water holding capacity of the farm’s soil, and this is correlated to a significant increase in carbon content. Root penetration is measurably greater on his soils than on any control site, and the full plant coverage means that water loss from the soil is greatly reduced.
He claims the following figures:
·       Double the organic carbon
·       Double the water holding capacity
·       All soil nutrients, including trace elements, have increased by 160%
·       Calcium increased by 277%
·       Soil pH gone from 5.2 to 6
Could all this apply to your farm? Arguably, many aspects of it could.
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