Tips from grain growers and agronomists on how to set up harvesters for chaff lining are contained in a new publication that can assist others considering adopting this low-cost harvest weed seed control tool.
Chaff lining is a relatively new practice that involves making a simple chute to divert the weed seed-bearing chaff fraction (from the sieves) into a narrow chaff line, which is left to rot or mulch while the straw is chopped and spread. Chaff lines are placed in the same place each year.
A new Grains Research and Development Corporation (GRDC) publication Tools and Tips: Setting up for Chaff Lining provides advice on the technique, which is being adopted by a number of Australian grain growers.
Planfarm project consultant Peter Newman, who is also an agronomist with the Australian Herbicide Resistance Initiative (AHRI) and GRDC-supported industry WeedSmart project, said chaff lining was the cheapest harvest weed seed control (HWSC) tool, both in terms of capital cost and overall cost.
"Controlled-traffic farming (CTF) systems are good for growers adopting chaff lining, but not essential, and it is sufficient for the harvester to run on the same track each year," Mr Newman said.
"Commercial chutes are now available, and many grain growers make their own."
The four stages of HWSC, as applied to chaff lining, that are covered in the GRDC publication include:
- Getting weed seeds into the front of the harvester
- Getting weed seeds out of the rotor
- Keeping weed seeds in the chaff fraction
- Delivering weed seeds into the chaff line using a chute.
Mr Newman said the publication had a particular emphasis on information relating to keeping weeds seeds in the chaff fraction and delivering weed seeds into the chaff line.
"To keep weed seeds in the chaff stream leading to the chaff line chute, it is necessary in some harvesters to insert a separator baffle behind the sieve in order to direct the chaff," he said.
"In some cases, inserting a baffle into a harvester can change the wind movement through the machine and can lead to increased grain losses, so it is important to use a tray or drop pan to measure grain losses and ensure they have not increased."
Mr Newman said one of the great things about chaff lining was that growers could build their own chutes, but chutes were also available from commercial manufacturers.
"Growers in different parts of Australia have created a plethora of different chute designs for a range of harvesters. Descriptions and images for a few of these, as well as commercially available products, are contained in the publication," he said.