How the Kahl family has fine-tuned their Namoi cotton operation
Merced Farming operations manager Sam Kahl in a field of Sicot 748B3F cotton at Glencoe, near Wee Waa. Pictures: Supplied
Gross margins, timing and availability of resources - not top yields - are the guiding light for the cropping team at Merced Farming in the NSW Namoi Valley.
Operations manager Sam Kahl said they had set a yield target of 12 bales per hectare for irrigated cotton.
"There's been years where we've got more than 12 bales, but we're growing the crop for a 12 bale target," he said.
"We see that as the greatest return on investment for inputs and we give the crop the inputs accordingly to try to reach that goal."
Other considerations include a desire to pick in April to avoid weather impacts on harvest and ensure subsequent winter wheat crops can be sown on time.
"Picking in May always seems a short road to picking in June, and that's not much fun," he said.
Merced Farming operates 7600ha across a number of properties in the Wee Waa district.
Mr Kahl, brothers Daniel and Matt and their father, James, produce irrigated and dryland winter crops of bread and durum wheat, and summer crops of corn, cotton and mungbeans.
They
also run a herd of 300 Angus breeders which graze on native and
improved pastures, and receive feed rations made from home grown oats
and millet.
Weaners are usually sold at about 350-400kg depending on the season.
Soils are mostly self-mulching clays; average annual rainfall is about 500mm.
Irrigation water is sourced from the Namoi River and groundwater licences, and crops are irrigated using a siphon and flood furrow irrigation system.
Assuming full water allocations, crops generally follow a six-year rotation that includes cotton every second summer and either wheat, mungbeans or corn in between.
Harvesting Sunmaster wheat earlier this month at Redbank, near Wee Waa.
Mr Kahl said the rotation was flexible enough to respond to changes in both commodity prices and water availability.
"It depends on which resource is the most available or least available," he said.
"If water is least available, you're then looking for a return per megalitre rather than a return per hectare.
"Corn is usually the first one to leave that rotation based on water consumption ... Sometimes mungbeans wins the battle and instead of planting 100 hectares of cotton, you plant 300 hectares of mungbeans and make use of a resource which you have plenty of, which is bare paddocks, in a low water year."
Regular soil testing guides fertiliser application which, as well as covering the major elements nitrogen, phosphorus and potassium, can include granular or foliar boron and zinc. Soil tests also help inform annual carbon audits of the operation.
Sowing of this season's crop started on October 3, but halted when temperatures dropped, and continued from October 10 with a target seed rate of 12.5-13 seeds a metre on one metre row spacings.
Dryland Sicot 748B3F cotton emerges earlier this month at Helebeh, near Wee Waa.
As well as the established varieties Sicot 714B3F and Sicot 748B3F, there is a 75ha trial plot comparing four new XtendFlex varieties - Sicot 761B3XF, Sicot 619B3XF, Siokra 253B3XF and Sicot 4133B3XF - against them.
Mr Kahl said he was keen to see how the new varieties might fit into the system, especially since they offered a stronger herbicide stack that could be useful for tackling glyphosate resistance in grass weeds and milk thistle.
The plan is to give the irrigated cotton up to 8.5 megalitres per hectare, depending on the season and in-crop rainfall.
Mr Kahl has allowed for two or three in-crop herbicide sprays to control liver seed grass and feathertop Rhodes grass, and the crops will be carefully monitored for pests and disease.
Integrated pest management has been a cornerstone of the cropping strategy and they succeeded in growing the 2020 and 2021 cotton crops using only spray oils.
"Beneficials are a massive part of what we do," he said.
"My happiest thing is to walk into a paddock and find lots of spiders.
"That's when we know we're doing something right, because they're doing the work for us instead of coming in there hot with chemicals.
"The last two years we've had to do only one spray each year, and that's usually towards the end of the season ... We're not against pulling the trigger, but we try our hardest not to go too early."
Verticillium wilt is a problem in some areas, especially where cotton has historically been grown back to back.
Alongside the crop rotations used to combat the soil borne disease, the Kahls are hosting a research trial as part of CSD's Richard Williams Initiative, testing the impact of different summer crops, such as sorghum, corn, millet and forage sorghum, on inoculum levels.
