Understanding how grass grows is good for farmers – and for business

 The warmer weather is coming!

At least that’s what I keep telling myself, and this recent weekend that seemed to be true. After several days with chilling rain and hail, morning frosts brought fine, warm days.

In much of New Zealand, this winter has been particularly wet, and recent weeks have carried some Antarctic blasts of cold to southern regions. In the Waikato where we are based though, warmer soil temperatures mean that we’re seeing some pasture growth again. If you looked at the paddock of annual ryegrass beside my house, you’d be forgiven for thinking that it never stopped!


Of course, annual ryegrasses are specifically grown for their ability to fill late winter feed gaps, something that farmers across the country address in a range of ways. Over the next two or three months, farmers will be keeping a very close eye on the balance between their feed supply, and the demand of their livestock. This is a process that has been made somewhat easier by the pasture growth forecaster we developed for DairyNZ and Beef+Lamb New Zealand.

The pasture growth forecaster uses daily climate data from NIWA’s Virtual Climate Station Network, soil water holding capacity information from Landcare Research’s SMaps and Fundamental Soils Layer, a sophisticated pasture growth and drainage model, and a learning algorithm that lets us improve forecasts for a farm when real pasture records are recorded. The pasture growth forecaster can provide forecasts down to a paddock level, or can be aggregated for district reporting.

Here’s a picture of today’s (18 August) short forecast for the Waikato. Growth is going to take a dip over the next few days with the next cold and stormy front coming through, but it looks set to pick up later as warmer, sunny weather returns. Of course the Waikato is typically mild; I hear that the limiting factor to pasture growth over much of the year is sunlight because of our cloudy weather.


As Pasture Growth Forecaster was funded by industry bodies, it has been made available as a “wholesale” service that businesses and service providers can use or integrate into farmer-facing tools. This helps us to make forecasts available to farmers in a number of forms. A range of businesses have integrated Pasture Growth Forecaster into their software tools, but farmers and professionals can also access it through Pasture Vibe (

Expect to see more businesses bringing the Pasture Growth Forecaster to farmers in different ways over the next few months. If you’re in a business that would benefit from integrating Pasture Growth Forecaster into your planning or farmer-facing tools, contact us.

Good pasture management is the key to farm profitability. DairyNZ and B+LNZ are confident that pasture growth forecasts will help farmers make better decisions on supplementary feeding, grazing rotations, silage making and nitrogen management. Funded by DairyNZ, B+LNZ and the Ministry for Primary Industries through the Primary Growth Partnership. Forecasts use NIWA data.