Early warning if summer turns dry

Waikato farmers may be up to their ankles in winter mud, but the recent rain has not penetrated down into the subsoil where it is needed most.

That could be a danger signal if the approaching summer turned dry, AgFirst economist Phil Journeaux told Waikato agribusiness leaders at the release of its annual financial survey for drystock and dairy farmers at Mystery Creek.

Above the surface, pasture covers were pretty good through May and June and calving was going reasonably well.

But below the surface, the subsoils were still dry, a legacy of the dry late summer and autumn where the region was about 300mm down on the average at the end of June.

‘‘As of the end of June, we have had 40 per cent of our average rainfall, so while the topsoil’s reasonably damp, the subsoil’s pretty dry.

‘‘Drains are not running that well and we actually need a lot of rain, 300-400mm, to catch up to the average.

"The danger at the moment is that if we don’t catch up and we have a dry summer, it will compound,’’ he said.

The steady rain that has hit the region over the past few weeks was not enough because it was still only the monthly average.

Niwa’s climate summaries for May and June largely back up his claim.

May was the third warmest month on record with soils drier than normal for much of the North Island and rainfall was below normal or well below normal for the majority of the North Island in May.

In June, rainfall was below normal or well below normal for the majority of the country.

While soil moisture levels were near normal across most of the country, there were pockets of drier than normal soils in a handful of areas including eastern Waikato.

New Zealand had its second warmest July on record with normal or near below rainfall for the region.

Its August-October outlook predicted rainfall and temperature levels for Waikato to be normal and soil moisture levels to be below normal.

Niwa climate scientist Chris Brandolino said a sustained period of steady rainfall was needed to bring moisture levels back to normal. The recent wet weather had helped, but in terms of the overall water balance, there may be a way to go to get back to equilibrium.

‘‘Additional rainfall wouldn’t be a bad thing so long as it doesn’t cause flooding,’’ he said.

The period from late autumn to early spring was critical because it recharged ground water, rivers, soils and lake levels through wet weather.

‘‘If that recharge doesn’t happen at the appropriate level and you go into some dry times, then you are setting yourself up for potential challenges as you enter the summer season.’’

He said it was still too early to speculate what kind of summer weather Waikato could have.