Maize is shaping up to be an option for South Island cropping farmers with a first-year trial showing a warming climate will allow maize to be grown in areas which have previously been marginal for the crop.
Plant and Food Research also forecasts larger and more frequent drought events in the North Island, so – depending on future spring and summer rainfall patterns in the North – the South Island may become a major growing region for maize, Foundation for Arable Research (FAR) maize researcher Dave Densley said.
Maize silage demand from the dairy sector is also increasing as its use can complement pasture-based systems nutritionally and economically.
However, for maize silage to compete with palm kernel as a suitable pasture supplement for South Island dairy farmers, economic yields and consistent forage quality are required.
Densley said for arable farmers maize can provide an alternative income as well as several agronomic benefits.
These include the opportunity to use different herbicide chemistry and nutrients that may not have been accessible to shallower rooting crops, reducing the risk of nutrient leaching.
Crop management will likely be different to the North Island with different cultivation methods being investigated to demonstrate how to plant and harvest crops commercially using narrow row spacing compared with the industry standard practices optimised for the major growing regions in the North.
Meanwhile this season, for the first time, maize growers and purchasers have the option of using a high-tech sensor as a measurement tool duringharvest for maize forage trading.
New Zealand is possibly the first country in the world to provide the option, streamlining the information-gathering process.
The near-infrared (NIR) spectroscopy sensor is mounted on the delivery chute of a forage harvester to measure whole plant dry matter as it passes through a field. It will provide an alternative to the current practice of physically collecting samples.
Densley said about 80% of maize grown in NZ is for silage with about half of that traded between maize growers and dairy farmers.
For a fair transaction to occur between grower and purchaser, determination of dry matter tonnes (tDM) requires accurate weights of each truckload harvested (wet weight) and the dry matter percentage of that forage.
“We are excited about the opportunity to use this NIR technology as a tool to determine whole plant dry matter percentage after a rigorous evaluation by our research team and other collaborators,” Densley said.
Most of the industry uses the good practice guide for the trading of maize forage, which has been available since the mid-2000s. The guide, now overseen by FAR, provides protocols for the fair trading of maize silage between growers and dairy farmers.
“Summers are becoming hotter and drier, so there is an increasing level of maize variability within the field, making the practice of hand-sampling to determine dry matter increasingly challenging.”
Contracts and protocols for using the new technology are available for the 2023 harvest.
