Mr Engelbrecht hosted more than 20 people at a Beef + Lamb field day on his farm in Goodwood earlier this month.
Mr Engelbrecht said he trialled 2ha of a raphanobrassica crop when the seed was first released nearly a decade ago.
Raphanobrassica, or raphano, is a hybrid of kale and radish.
The trial crop’s yield and regrowth and the performance of the lambs put on it was disappointing.
"I hated it."
A reason for the crop’s poor performance could have been because it was in heavy soils and they had plenty of rain that season.
On a trip to Dunedin, he saw a similar crop performing to its potential in a dry paddock.
This season, he planted 60ha of the crop in a bid to avoid having to sell store lambs.
"I’ve gone from 2ha and not standing the sight of it, to 60ha this year — it was either going to kill me or be OK."
Catalyst Performance Agronomy agronomist Craig Cox, of North Otago, said if farmers did not plant a summer crop they were at "the mercy of the dry" and might need to sell store lambs and take a financial hit.
"You are all livestock farmers but first and foremost you are moisture farmers."
The moisture tap was on in spring and got turned off some time between November and February.
"We try and grow a bank of feed with the spring moisture to get us through a dry summer and keep us going."
The simplest option was a summer rape crop but it needed to ripen before it could be grazed, starting from 70 days after sowing, depending on the variety.
A raphano crop performed in dry conditions and did not need to ripen like a rape crop, so could be grazed sooner.
The seed costing per hectare for rape was between $70 and $100 depending on the cultivar, about a third of the cost of raphano at $285/ha.
A raphano crop could not be left too long to grow beyond knee-height because it got "stalky" and the utilisation and regrowth potential was reduced, Mr Cox said.
Mr Engelbrecht said his raphano crop had been grazed three times and would be grazed again.
"You’ve got to give it a hard time."
He found the farmers who loved raphano tended to be those with big numbers of lambs.
"You’ve got to deck it and get off."
However, lambs preferred other types of feed to raphano, he said.
A benefit of having 60ha of raphano was it allowed him to put thousands of animals on it and shut up other areas of the farm to focus on growing quality feed.
"That’s been a real benefit."
His "gut feeling" was lambs would put on more weight on a paddock of rape than raphano, Mr Engelbrecht said.
However, a raphano crop lasted longer than a rape crop and could be grazed more times.
"Nothing is perfect but I think raphano might have a place around here."
Raphanobrassica
Average yield: Up to 10 ton/ha.
Grazings: Up to 4.
Pros
— No need to allow to ripen, making start date flexible if grass growth stops.
— Clubroot tolerant.
— Drought tolerant — 38% water-use efficiency compared with rape.
— Good winter graze potential.
— Good opportunity for thistle and weed control.
Cons
— More expensive seed cost ($285/ha).
— Cannot be deferred too long after emergence or quality and utilisation declines.
Source: Catalyst Performance Agronomy
