A NEW approach to autumn fodder could mean valuable home-grown feed for dairy cows in the autumn and winter when feed is often limited.
Future Dairy project leader Dr Yani Garcia said intercropping trials using late sown maize with a brassica (forage rape) yielded 15 tonnes drymatter (DM) of high quality fodder using just 1.5 megalitres (ML) of irrigation water.
He said that could be an option in irrigated paddocks where maize is harvested for silage in January but it was still too hot to sow annual ryegrass.
“A cheap corn variety or old hybrid seed could be drilled immediately into the maize stubble.
“Forage rape seed could than be broadcast with fertiliser a few weeks later, when the new maize was already up to provide some protection for the brassica seed.”
Maize sown with brassica in February can be grazed first at about 1.2m high; the maize will not re-grow but the forage rape than takes over to provide grazing for the whole autumn and winter period.
That gave better water use efficiency partly because evaporation is lower in the cooler months and partly because of the higher natural rainfall in winter.
Maize and brassica out yielded other intercropping combinations such as maize/ryegrass and maize/Persian clover.
Dr Garcia said maize and brassica are a compatible combination with the high yielding maize requiring a lot of nitrogen but the Brassica is a legume so adds nitrogen that can be used by maize and by subsequent crops.
