The science of soil biology is catching up with a gut feeling of "muck and mystery" that drives natural regeneration, but there is much more work to do, according to research ecologists. Ahead of World Soil Day (December 5), students at Lismore's Southern Cross University were presented with a whole host of reasons to work in this growing field - if only to save the human race. The science of humus was once passionately debated in academic circles with the height of published literature peaking before World War One. The invention of the Haber-Bosch technique precipitated the "Green Revolution" after World War Two. "This addition of N fertilisers hastened the breakdown of organic matter in soil, while replacing widespread use of legumes, which had added organic matter as well as nitrogen," said director of Lismore's acclaimed Environmental Analysis Laboratory, Graham Lancaster. But there is a change afoot, and that is the realisation that nature's biological processes can renew carbon deficient soil provided human managers factor that into their day to day work. In the past 10 years research has shown how roots trade sugars for nutrients, literally off the backs of bacteria and fungi. When "easier" forms of nutrition are applied in granular form that relationship with the rhizosphere goes away and the living soil takes a step back. As students grapple with ways to help their generation survive - and thrive - faculty and graduates from Southern Cross University, with help from the Southern Queensland Northern NSW Innovation Hub, offered practical advice to future leaders of soil science. Mr Lancaster explained how water quality and human health all linked back to soil quality. "In many ways it's about keeping biology in balance. Soil is such a complex organism that it works without interference," he said. The story about phosphorus is an example with the litany of environmental damage from acid run-off still apparent from a legacy mine in South Australia that chemically eroded rocks to make super-phosphate fertiliser. Scientist today have evidence that fungal hyphae deliver phosphorous molecules into the root tips of needy plants - in exchange for exudates. More recently, science has "discovered" that the billions of bacteria in soil communicate similar needs and demands through chemical stimulus. Such is the detail of work being discovered - and yet to be learned - that students interested in entering the field will enjoy a lifetime of interest. Molecular microbial ecologist, Dr Kattie Weigh based at the Wollongbar DPI research farm, related a tale of her own discovery investigating chemical signalling between bacteria keen on resolving a nutrient problem. "The exudates of a phosphorous deficient plant attract bacteria that aid in the plant's stress relief," she said. "They attract phosphorous-solubilising bacteria." Ecology lecturer John Grant brought the topic down to earth when he said: "Stand in soil in your bare feet. It's part of our heritage. Soils under our feet are what put us here and keep us alive." Monaro horticulturalist and student of regenerative agriculture Greg Colton argued that, "if you're not a soil steward then you're not going to have farming in 100 years. It's imperative we preserve soil structure. If you kill the biology you are preventing plants from defending themselves".