Most parts of the country are currently affected by dry weather, with each region having its own hotspots impacting on farmers, said DairyNZ farm performance general manager, Vanessa Winning.
“A few areas in both the North and South Islands had some rain recently, but most areas need a really good soaking coupled with follow-up rain to get soil moisture levels up to support grass growth,” said Ms Winning. “For most regions in New Zealand 70-130mm of rainfall is needed to fill the current soil moisture deficit.
“We know some farmers have reduced their milking frequency as a way of managing through what are still very dry conditions. Other farmers have sought to reduce feed demand by selling empty cows and other known cull cows, and drying off young light condition cows.”
In the lower North Island, central Manawatu and Rangitikei are badly affected and farmers should take action now, if they haven’t already. The rest of the lower North Island is variable, with some dry pockets and others that have had good rain.
In the upper North Island all areas are affected, but to varying degrees. Bay of Plenty and Central Plateau are very dry – and often are in summer. North Waikato and some parts of Northland are drier than usual.
The top of the South Island is particularly affected by dry conditions, with drought declared in Tasman and support available to farmers from DairyNZ, Federated Farmers, the Rural Support Trust and others.
Other South Island areas particularly affected by the dry weather is the northern West Coast including Karamea, Westport, Reefton and parts of Grey Valley. Southland and Canterbury are aided by irrigation, but irrigation restrictions are coming into effect.
Ms Winning says pasture growth rates are a key measure of how dairy farms are managing the dry.
Farms involved in DairyNZ’s Tiller Talk project have recorded pasture growth rates that are far lower than this time last year. On average in February, the Waikato farms grew 33kg DM/ha/day less grass, while the Marton and Masterton farms were 37kg DM/ha/day lower.
“Although it does vary, especially across the South Island, we know that in dry summers 20 March is the date by which we need substantial rain before farmers consider drying off most of their cows to secure pasture and ensure cow condition targets are met for the next season,” said Ms Winning.
“The key thing when managing through the dry is to have some cows in milk when it does rain. Although, there will be exceptions to this where the dry conditions have been a lot more extreme and farmers have had to dry off their cows early.”
Meanwhile, farms which have received rain or have irrigation will be focused on making the most of it. “Up to half the grass available is lost after rain because dry material begins to rot and decay quickly, so cows will require the major part of their intake from supplement,” says Ms Winning.
“A slow rotation is also needed – this will allow pasture cover to build and pasture growth to be maximised. In March, nitrogen applications should be delayed for three weeks after significant rain (more than 50mm) to allow surplus nitrogen in the ground to be utilised first. If no significant rain is received until April, nitrogen should be applied as soon as possible after the rain.
“If strategic irrigation has been used and parts of the farm have been under-watered, the above would also apply to dry areas.”
DairyNZ advice and guidance on feed planning and summer management is available on www.dairynz.co.nz/summer, at DairyNZ discussion groups or via a local consulting officer.
DairyNZ’s Tiller Talk helps farmers improve their pasture and feed management by providing a forum to share information and access advice. Its farmers, located in most regions nationwide, have also provided information on how they are managing with low soil moisture levels. Visit www.dairynz.co.nz/tillertalk for their March update.