Farm Dams & Paddock Walk
Hay Plains Landcare hosted a Farm Dam workshop and Paddock walk of local revegetation sites in Hay on Thursday 23rd of June. The Workshop was led by ecologist Mason Crane of the Biodiversity Conservation Trust. Mason discussed the benefits of healthy farm dams for the environment, biodiversity and livestock health and productivity.
A healthy Farm dam provides drinkable safe water for livestock and retains water for longer and in dry periods while supporting native plants and animals and providing ecosystem services to the surrounding landscape.
“From a Livestock point of view, it’s important to have healthy water.” Water Runoff can fill your dam with loose organic materials from the catchment, which can lead to the water becoming unattractive, contaminated, and possibly toxic to livestock. Palatability of the water results in less water being consumed by livestock; if livestock are dehydrated, they don’t eat as much and can’t convert their food into quicker growth rates. One Canadian study on water quality showed a 20% increase in growth from livestock drinking out of clean, fresh water pumped from the river into troughs compared to dams out in the field. “A strong indication of how important water quality is” Mason Said. This study was taken on normal day-to-day drinking of water. A dry year will often result in disease outbreaks. Water quality can have a devasting effect on the stock. Blue-green Algae can be devasting “you can lose a couple of beasts overnight”. Mason also spoke of a landholder who lost 15 in just over a week. Leptospirosis is also spread by livestock urine contaminating the water and this disease often results in fertility problems.
Mason gave insights into how ground tanks can be designed or improved. “By creating 1 access point which is gravelled, or having a trough and reticulation system you can recover the money you spend fencing-off dams or cleaning them out within about 8 years. “
Unlike reservoirs and some of the bigger storage dams, farm dams haven’t been used to calculate our national greenhouse gas emissions, although they are a large a contributor. In 2018 Deakin’s Blue Carbon Lab team found that farm dams emit significantly more greenhouse gases than lakes, reservoirs, and many natural freshwater systems. “Dams are often in low places so they catch all organic material that runs off the paddock, The dam becomes a big fermenting gut. It is calculated that 11 grams of carbon dioxide per square meter per day are emitted from a dam.” based on the average calculation, 2.4 tonnes of carbon dioxide a year would be released into the atmosphere at the first farm dam that was sited at the workshop.
Latest research, (published in the prestigious journal Global Change Biology), Dr. Malerba and Deakin’s Blue Carbon Lab researchers collaborated with the Sustainable Farms team to look at the impact of fencing out a dam and reducing the amount of organic material running into the dam. They discovered that by fencing around farm dams to prevent livestock access and allowing native grasses to grow and the natural environment to thrive, carbon emissions reduced by 56%. Fenced farm dams also recorded 32% less dissolved nitrogen, 39% less dissolved phosphorus, 22% more dissolved oxygen, and produced 56% less diffusive methane emissions than unfenced dams.
The study also found that farm dams with high dissolved oxygen can stop emitting methane and start absorbing greenhouse gases from the atmosphere. “You also have the potential of carbon storage on the outside of the dam by planting trees, shrubs, reeds, and grasses, turning something that is emitting carbon into something that is storing carbon,” Mason said. The presence of this fringing vegetation can also shelter the dam surface and reduce evaporation from the wind.
Healthy wetlands are rare. Healthy farm dams can play a similar role to natural wetlands – helping restore biodiversity by providing much-needed wetland habitats for native wildlife. “Further east most of the towns like Tarcutta, Cootamundra, and Junee were built on big wetlands that have been drained. Dams are the only thing that resembles a wetland other then creeks and rivers that are often highly degraded.” – Mason Fenced-off, well-vegetated dams become a good habitat for invertebrates, fish, frogs, turtles and birds. These water species then help to improve the dam function by cycling nutrients from the dam into the wider landscape, helping reduce sediment, nutrient, salts and algal levels within the dam. “Farm dams provide that wet refuge for our wetland species, but they are often grazed right to the edge, there is dirt and limited habitat value” Mason explained
Field Trip to Savernake
Friday the 6th of May, 26 Landcare members had the opportunity to travel to Savernake and visit Savernake Station, Boat Rock and 5 Plain Forest. Member had the opportunity to explore the benefits of retaining native vegetation and identified native plants and Aboriginal culture sites along the way. Savernake Station is renowned for its pastoral history, but also for its large white cypress pines and other old trees. The woodland survives because previous generations of Helen Huggins , the Sloane family, fenced off part of the property in the early 1900s.
The 355 hectares of land is funded by the BCT under a Conservation Agreement, in perpetuity provide. land that provides habitat for about 80 species of birds, including vulnerable species such as the diamond firetail and dusky wood swallow.
Boat Rock is one of the largest known Aboriginal rock wells in the region with a wonderful water catchment, which was made by “burning out” the rocks to catch and hold water for use over the summer period. “Burning out” was created by a big fire that was lit on the site then allowed to cool, then cold gravel would be loosened and dug out. The same process would then happen again, and again. It is in the perfect position to catch the entire run off the granite outcrop into which it has been made for. The rock well only needs a small shower of rain to fill the hole with water, which this water is very necessary over the summer period.
Practical Seed Cleaning Workshop
Friday 18th of March, Natasha Lappin from Murray Local Land Services provided a hands-on seed cleaning workshop at the Murray seed bank in Deniliquin. The workshop included a tour of the Murray seed bank, seed cleaning demonstrations, wet seed processing demonstrations, and participants cleaning their own seed.
Practical Seed Collecting Workshop
Friday 18th of February, Bill Auldist from Riverina Local Land Services provided a practical seed collection workshop at ‘Oakville’ Conargo. Bill covered collecting, cleaning, which tools to use, where to collect from, Health and safety, reporting and discussed when permits are required.
Seed collected: White Cypress Pine – Callitris columellaris, Hop Bush – Dodonaea, Cassia – Senna artemisioides, Nitre Goosefoot – Chenopodium nitrariaceum, Spiny /Thorny Saltbush – Rhagodia spinescens, Cooba – Acacia salicina