Managing waterlogged pastures
24 October 2016
A series of extremely wet months has left many pastures and paddocks water logged across the Central Tablelands, but there are practical strategies farmers can implement to make the most of the wet conditions, according to Senior Land Services Officer - Pastures, Phil Cranney.
“On the upside, there is almost always more money in mud than in drought induced dust, however the wet conditions have caused some serious problems to pasture quality in the worst affected paddocks,” said Phil Cranney from Central Tablelands Local Land Services.
“Where water has lain on a paddock over a long period, plant roots will start to die from the tips up because of the lack of oxygen in the soil. Nitrogen and other nutrients will also leach away from the root zone.”
“Denitrification occurs when the soil microbes run out of oxygen to breathe and start to use nitrogen. This causes nitrous oxide emissions (a green house gas) and is another cause of nitrogen loss from soil.”
“There are no good short term pasture options for flooded paddocks. The best option is to focus on medium term recovery of the pasture base, and to address any immediate animal welfare issues by supplying supplementary feed,” advised Phil.
“If pasture is covered with silt or mud, converting it to silage is not an option as the dirt will contaminate silage fermentation.”
“Where the plant mass is lying on the ground, it will take longer to dry out and there is a greater chance of moulds or mycotoxins developing.”
“With taller winter crops that have not been inundated, but have been waterlogged and are unlikely to make grain, chopped silage may be an option if equipment can get on to the paddock. It is still essential that the plant mass is able to wilt properly and an inoculant should be used to improve quality.”
“If pasture survives inundation or water logging and can be grazed, palatability may be an issue. Delaying grazing until there is further storm rain to wash the silt off the pasture may improve utilisation by stock.”
“Where pasture has deteriorated severely, it may be worth ear marking that paddock for renovation, by brown manuring, then spraying out the pasture and letting it mulch down into the soil over the summer months.”
“If pasture has died, shirohie millet is the quickest option for providing short term green feed. If sown heavily, it is also a great competitor against any new weeds inherited from up stream. However Tablelands farmers need to be aware that shirohie millet needs a soil temperature of at least 14 degrees to germinate.”
“If producers have surface applied limed on their paddocks within the last 12 months, one of the benefits of the above average rainfall, is that it should help wash the lime deeper into the soil, therefore having a greater neutralising effect on toxic aluminium cations.”
For more information about managing water logged pastures contact your nearest Local Land Services office or phone Phil Cranney on: 0458 745 478 (email: firstname.lastname@example.org)
Media enquiries: Kylie Krause | 0439608370