Irrigation pays dividends for Polson farm in Mangamahu

The Polson's irrigation system produce the lush green pastures over summer in dark contrast to the dry surrounding hills. Photo / File

Mangamahu farmers Donald and Liz Polson are receiving payback from the Mangawhero River that has often threatened to destroy their livelihood.

The husband-and-wife team installed an irrigation system on a Ngaturi block on their Waipuna farm adjacent to the Mangawhero River three years ago.

Ironically, this block was severely flooded during the devastating 2004 storm that claimed thousands of Polson lambs, Donald's late brother Alistair and his wife Bo's home and left river silt at least a metre thick over the 130ha flats.

The same block was less affected in the 2006 event, but succumbed again to weather in the June 20, 2015 storm.

The Polsons run three farms - Waipuna, a 1600ha mainly medium to steep hill country block spreading from Mangamahu across to Aberfeldy on SH 4 and Te Tui, a 600ha farm near Fields Track. The third farm is Awarua, a 512ha unit near Raetihi they own in partnership with corporate lawyer Dave Boswell.

A further irony is that the total 520ha of river flats and terraces at Ngaturi are prone to summer drought.

Donald said the policy was to get the lambs off by summer's end to avoid carrying light ones through into winter.

In the past that hasn't be achievable. Donald says in the past they had found ways to finish most of the lambs, even resorting to feeding grain pellets at times.

"But we've always ended up carrying a lot of light lambs through into winter," Donald said.
The philosophy was that if he could get them through the summer they would be valuable lambs.

While floods have ravaged the area on occasion, summer drought has also played a major role. In fact, two droughts in a row is mainly what prompted the Polsons to resort to irrigation.

The advantages of the irrigation system is the timely reliability of feed, it washes down and dilutes facial eczema spores and allows the Polsons to take the lambs through to killable weights.

Mr Polson said two out of the three years the sprinklers were busy.

"This season in particular we had the sprinklers on 24/7 and it just about paid for itself - it was a godsend. Last year we hardly used it. One of the problems is that the Mangawhero is sometimes quite muddy and the valves get clogged."

An interesting sidebar was that a visiting Japanese film crew used the irrigation system in full swing as a backdrop to a segment of their programme.

"They were making a film about a well-known Japanese chef and they came to our place to film. She then cooked for us using our own lambs - it was delicious," Mr Polson said.