Green harvesting pays
Tweed Valley sugarcane farmer Robert Quirk is green harvesting his cane and coming up with innovative solutions to nurture his soil.
Robert uses his green cane tops as mulch.
He doesn’t burn his cane and the vital carbon found in the trash is returned to the soil instead of going up in smoke.
The key to using the cane trash is the addition of nitrogen to facilitate its breakdown so it doesn’t build up to a height where it encourages conditions for disease or pose a problem for farm machinery.
Robert applies two kilograms of nitrogen per hectare to the cane trash after harvest with a boom spray.
He believes the addition of organic matter has enabled him to start growing legume crops during the cane fallow period, something he has not been able to do successfully for 30 years.
The soybeans or lab lab are not fertilised, nor is the soil cultivated prior to sowing.
They are simply planted directly into the trash.All grow well and supply nitrogen for the next crop, improve soil structure and provide a bit of cash.
Another fallow plant Robert has used has had additional unforseen benefits - a crop of oats reduced nematode levels drastically.
In addition to all this he mounds up the soil and plants cane into the mounds.
Raising the land for the growing cane is important on a property that is very close to sea level.
Before the mounds are created, lime is added at five tonnes per hectare and then the top 20 millimetres or so is scraped into mounds.
This means the lime application rate in the mounds is now closer to 10t/ha.
To reduce risk of soil structural problems, such as compaction from the heavy machinery used in cane farming Robert employs the technique of controlled traffic or tram tracking.
This means that the mounds in which the cane grows are never driven over and heavy machinery is confined to the inter-row areas.
The addition of the organic matter from the cane trash and a legume crop every 4 or so years means that minimal soil structure damage occurs.
One of the biggest pluses, though, has to be the reduced need for fertiliser.
Robert estimates that he needs 25% less fertiliser than he did before he started mulching with trash with no decline in productivity.
Contact Abigail Jenkins, NSW DPI, Wollongbar 6626 1200.
This story appears Agriculture Today.