Irrigation New Zealand

A party of 25 New Zealand irrigators, farm and environmental consultants and irrigation schemes and service industry representatives has returned from a trip to Nebraska with some fresh ideas about how to improve environmental management in New Zealand.

IrrigationNZ organised a five day trip to Nebraska for its members. 18 of the group came from Canterbury, and 15 were farmers. The party visited the Husker Harvest days – the world’s largest irrigated farm show, the University of Nebraska’s Water for Food Global Institute, research farms and research trials, irrigation schemes, natural resource districts which manage water resources and irrigation manufacturers.

Nebraska's history
“It was really interesting to hear the history of Nebraska from different experts. Nebraska was one of the states which was devastated by the dust bowl storms in the depression and farming families had to leave the land. After the depression they started to adopt better land management practices to keep their top soil. They also invested in irrigation systems and the state is now very productive,” says Darfield farmer Paul Jarman who joined the tour.

By 1932, 750,000 acres of farmland had been abandoned in Nebraska due to soil erosion and dust storms. One of the worst dust storms occurred on 14 April 1935 on “Black Sunday” when strong winds blew an estimated 300 million tons of topsoil from the prairie states as far as the East Coast and Washington, turning the sky black in its path.

Approach to water and environmental management
More recently Nebraska has experienced some of the problems New Zealand is currently focused on. Nitrates in groundwater are a significant concern. However, the state has managed to turn a trend of increasing nitrate levels around in many areas.

“The changes have largely been achieved by taking a non-regulatory approach. Water quality and quantity management plans are developed which identify any problems. An implementation plan to address the issues is also developed. Groundwater is managed by local Natural Resource Districts which have elected boards made up mainly of rural representatives,” says IrrigationNZ Chief Executive Andrew Curtis.

“The farmer representatives are very proactive in encouraging other farmers to adopt more sustainable practices. The districts have focused on data collation, investment in good science, farmer-to-farmer education, and best practice standards coupled with incentives. They are investing in a range of farm and catchment based solutions like river augmentation and managed aquifer recharge projects. The widespread move from surface flood to centre pivot irrigation has also been key to reducing nitrate losses to groundwater.”

Timaru based Irricon Resource Solutions Director Keri Johnson joined the tour. Keri is also a farmer and a Board Member of IrrigationNZ.

“Nebraska is a state where everyone acknowledges that agriculture underpins their economy. While New Zealand generally requires that individual farmers ‘cut back’ activities, Nebraska takes a more holistic approach. One example of this was that a stream flow needed boosting to protect an endangered species. The solution was to purchase a large groundwater irrigated farm, retire all irrigation, and use the farm’s groundwater to augment the stream. This achieved the environmental outcome everyone wanted while protecting the economy,” says Keri Johnston.

The use of fertigation in Nebraska
“I was extremely impressed at the use of fertigation equipment and the American’s ability to analyse and better increase their yields. Where nutrients are applied when and where they are needed, losses are low but production is maintained. It seemed clear this needs to be adopted as soon as possible in New Zealand. The use of a pivot as an applicator of nutrients or chemicals would hugely reduce costs,” says Irrigation Designer Jon O’Sullivan of Grafton Irrigation in Timaru.

Fertigation can deliver small amounts of liquid nutrients to a crop through centre pivot and linear move irrigation systems. It is commonly used in Colorado and Nebraska. Trials by the Irrigation Research Centre in Yuma, Colorado, and the University of Nebraska have shown that fertigation reduces the amount of nitrogen that is applied, while providing more consistent yields. IrrigationNZ is currently developing a guide to using fertigation in New Zealand.

Ashburton farmer Charles Ross was also interested in using fertigation on his farm, along with some of the new irrigation technology the group saw. “I will be looking at fertigation as a way to lower our nutrient loading, and I also want to control all the pivots on our property from a cell phone as soon as possible.”

“I have no doubt this trip has encouraged collaboration within our sector and I know there are opportunities that will deliver improved environmental and economic results in both the short and longer term,” says Mel Brooks, Chief Executive of MHV Water, one of New Zealand’s largest irrigation schemes.

How does NZ compare with Nebraska?
The group had mixed views on how Nebraska compared to New Zealand in terms of its approach to environmental management.

“New Zealand is very heavily regulated from an environmental point of view, and this can often lead to lost opportunities as we focus too much on regulation. In contrast, Nebraska has very little environmental regulation, with a real acceptance of how vital agriculture is to their economy – potentially sometimes to the expense of the environment. Enforcement is a last resort – they prefer to influence to achieve behavioural change. And from our perspective, this appears to largely work. However, some of their management does appear to be a little dis-jointed – managing surface water independently from groundwater for example. In my view, the answer is somewhere between the two Nebraskan and New Zealand approach – more of a balanced approach between the environment and the economic/social factors,” says Haidee McCabe, Director of Irricon Resource Solutions.

“To deliver sustainable solutions we need to continually challenge the status quo. We don’t have the monopoly on good ideas so having the opportunity to see how Nebraska is responding to challenges and how they are balancing environmental, social and economic outcomes was thought provoking. Spending time with industry experts and researchers was hugely beneficial and reinforced that in New Zealand we are progressing well in our journey to improved water quality outcomes,” says Mel Brooks.

Amongst their busy schedule the group also had time to cheer for the Cornhuskers football team at a college match along with 90,000 other fans, and visit the Rocky Mountains in Colorado.