Molloy family, The Rock NSW
Michael and Leanne Molloy and their sons Josh and Matt run a fully integrated mixed farming enterprise on properties south of Wagga Wagga, NSW, where mixed species brown manure crops and pastures provide fodder for the sheep, boost soil fertility and control grass weeds.
The 1900-ha aggregation of farms in the Yerong, The Rock and Henty districts centres on a winter cropping program that includes 1100 ha of wheat, canola and barley harvested for grain, 550 ha sown to perennial legume pasture and 100 ha of vetch-mix fodder. The vetch-mix fodder crop is brown-manured, and the perennial legume pasture phase runs for 4 to 6 years, providing multiple benefits to the Molloy’s farming system.
The remaining 150 ha is less arable and more frost-prone, so these paddocks are cropped less frequently, staying in a perennial pasture phase of lucerne, tall fescue, Phalaris, and clover for about ten years.
The Molloys run 3200 merino ewes and a flock of merino wethers, which they use as a relief valve to lighten the stocking rate if conditions dry off. The livestock represent 50 per cent of their farm business, with the sheep being an integral part of the cropping system, grazing on short-term perennial pastures, vetch-mix fodder crops and crop stubble to make the best use of the 520 mm average annual rainfall.
Two-thirds of the merino ewes are joined to merino rams for fine wool production (17 micron), and the rest are joined to white Suffolk rams for prime lamb production.
Each year, the top half of the male merino lambs born are added to the flock of wethers, earning a premium for their fine wool. The bottom half of the male lambs are sold at 12 months old. All the merino ewe lambs join the breeding flock.
Cross-bred lambs are grown out on the farm, grazing on the vetch-mix fodder crops or legume pastures until the feed supply runs out. They are sold mainly as trade lambs at the Wagga Wagga saleyards, over the hook or on AuctionsPlus.
Michael maintains high stocking rates while the feed supply and ground cover are adequate. When ground cover is reduced to 70 per cent, Michael moves the sheep off the cropping paddocks and into containment feeding lots where they are fed barley grain and straw. The Molloys store about 550 t of barley grain as a drought-feeding reserve and sell the rest in spring when they are confident of the feed supply for the season.
Michael says that palatability for the sheep is the main factor influencing the choice of species used in their mixed-species fodder crops and pastures. They fertilise the legume-based pastures to boost plant vigour and fix more nitrogen for the subsequent grain crops. This also promotes high biomass production in pastures, which builds soil structure and adds organic matter to support the grain cropping phase.
Since the pastures and fodder crops are important components of their weed management program, Michael wants to avoid having areas of low soil nutrition or other soil constraints where weeds can flourish.
WeedSmart Big 6 in action
Annual ryegrass is the main weed on the Molloy’s farms, along with some broadleaf weeds, but overall, their farming system keeps weed numbers very low. The Molloys purchased a new farm near The Rock in 2017, which was carrying higher ryegrass numbers, having been cropped continuously for many years. Michael says it took a few years to bring the weed numbers down using their system, but the black oats and ryegrass seed banks have now been reduced to very low levels.
The Molloys first noticed herbicide resistance on their farm in 1992 when annual ryegrass survived an application of Tristar Advance (Group 1 fop) for black oats control. They now use a mix of herbicides across their diverse cropping rotation to reduce seedbank numbers, especially for annual grasses.
Using the tactics in the WeedSmart Big 6 strategy keeps weed numbers low and reduces the risk of herbicide resistance in the Molloy’s mixed farming enterprise.
The Molloys use a short-to-medium-term crop rotation that includes a brown manure cover crop and a pasture phase. Generally, the crop sequence is canola, wheat, canola, wheat, barley and brown manure vetch-mix, followed by canola and wheat, then a 4- to 6-year legume pasture phase before returning to grain production.
Michael assesses the cropping area each year and may keep some paddocks in the crop rotation longer than usual. This is where the brown-manured vetch-mix is added to boost soil fertility and strategically control ryegrass.
The mixed species fodder crop is usually vetch-based with other species such as buster radish, purple top brassica and arrowleaf clover to provide nitrogen and soil structure benefits, and a cereal, such as Illabo wheat, to provide early biomass.
Michael sprays out the grass weeds and cereals from the vetch-mix in late August with butroxydim + clethodim, then brown manures the paddock in late October with a spray fallow of glyphosate and double knock of paraquat. Canola is sown the following season, serving as a double break for grass weed control. They can then plant wheat into a very low weed seed bank environment.
The pasture phase begins with 5 kg/ha barley undersown with 4 kg/ha lucerne, 3 kg/ha subclover and 0.5 kg/ha arrowleaf/balansa clovers. Two years prior to termination of the pasture phase, the annual grass weeds are spray-topped with paraquat. The pasture is spray-fallowed (brown-manured) the following spring, leading into the crop phase.
There is less selection pressure on herbicides during the pasture phase than during the cropping phase – a valuable strategy to keep key herbicides working in the Molloy’s farming system long into the future.
The Molloys plant their crops on 250 mm row spacing using a tined planter with presswheels. They have a partial controlled traffic farming system where they sow with a 9 m wide bar and spray and spread on 27 m widths, but their harvester is not aligned with these wheeltracks.
They have conducted electromagnetic (EM) surveys combined with a comprehensive soil testing program to map areas of sodic and acidic soils across the farms. Using segmented soil testing for pH and sodicity, they identified three variable rate zones for gypsum and lime. Gypsum has been applied at rates of 1 to 3 t/ha to address sodicity, and an additional 1 t/ha is surface-applied every 4–5 years as required. They hire a Horsch Tiger cultivator to incorporate lime to a target depth of 15 to 20 cm to address subsoil acidity.
Canola is a vital crop in their weed management program. To maximise crop competition, they grow hybrid Clearfield canola varieties, ensure good soil health, fertilise to yield potential, establish an even stand at optimal plant density and sow their crops early. Michael has adopted recommendations from Rohan Brill’s research in the region, which clearly showed the yield and weed control benefits that flow from sowing hybrid canola early to increase early crop vigour.
They also aim to maximise crop competition in their wheat crops by sowing at the front of the optimal window for each variety in their locality. Their main varieties are Raider, Scepter and some Illabo (dual-purpose).
Over summer, the sheep graze in all their cropping paddocks, utilising the stubble, sprayed weeds and volunteer crop plants. This grazing pressure on stubbles complements the summer weed control program.
There are some occasions following very high-yielding crops where stubble burning is necessary. Even with RTK on their tractor, the planter is pushed to its limit in years such as 2024, where the coulters struggle to cut through heavy stubble cover on dry soil.
The 27 m Goldacres boom spray has 250 mm nozzle spacing and the capacity to get around the cropped area in a timely manner, using four fill points around the farms. In-crop and summer spraying is done with air induction nozzles to minimise spray drift while optimising herbicide efficacy.
The Molloys use 2,4-D strategically to target problematic weeds, such as fleabane. The sheep also help control broadleaf weeds, like sowthistle, and provide a double or triple knock effect on sprayed weeds.
They use robust herbicide label rates, and no rate creep is evident. Although they can’t currently justify purchasing an optical sprayer for their cropping area, Michael sees the potential of this technology in maintaining paddocks at low weed density.
The Molloys find that the pasture phase and brown manure vetch-mix are very effective in keeping their weed numbers low in their grain crops. The flow-on effect of the low weed numbers is that there is less selection pressure on their herbicides.
A pre-emergent mix of propyzamide and trifluralin is applied to the Clearfield canola and followed by an in-crop application of Intervix, Lontrel and clethodim at the 4–6 leaf crop stage for a 100 per cent weed kill.
The following wheat crop has a pre-sowing double knock followed by a pre-emergent mix of Sakura (or Boxer Gold) and trifluralin. They usually apply one in-crop spray for broadleaf weeds along with a fungicide.
In year 3, the canola crop generally requires less chemistry than the year 1 canola crop.
Michael monitors for wild oats, fleabane, and windmill grass and knows that brome grass and feathertop Rhodes grass are present in their area. They use a variety of herbicides to keep their fence lines and fire breaks bare.
Brown-manuring the vetch and spray-topping in the pasture phase are the main strategies used to stop weed seed set. The Molloys have also used crop-topping in canola and barley in the past and would use this tactic again if weed numbers escalated.
In 2019, they sprayed out and cut some crops for hay as part of their program to reduce the weed burden on a newly purchased farm. During drought years, they often cut some canola crops for hay to conserve fodder for their sheep and sometimes bale barley straw as a reserve feed supply. Although rarely implemented, these strategies effectively stop weed seed set in drier years.
Ten years ago, the Molloys did some narrow windrow burning as a harvest weed seed control tactic, mainly on their Henty farm. Since then, they have found that their crop and pasture rotation is keeping the weed seedbank low, and HWSC has not been necessary.
Their efforts to keep weed numbers very low throughout the long crop rotation is paying off in the long term.
Weed-free Scepter wheat crop sown in 2024 after 44Y14 canola in 2023 and brown manured vetch mix in 2022.
