Healthy land for healthy food

Key NZ research aims to provide more food, more sustainably.

The grower of the future activated the Plant & Food Research app on a smartphone. There was land crying out for a profitable crop to be planted but first vital information was required.

Information like how much nitrogen is in the soil, what nutrients are needed to grow the crop and how to best protect and benefit the soil, so it would be ready for the next crop after this one.

The app doesn’t yet exist – but it or something very like it soon will, says Dr Trish Fraser, a team leader and part of the Plant & Food Research team looking deeply into sustainably growing more food from the same land and keeping the soil healthy for future generations.

“In the end, the key aspects of the work we are doing with the farmers and growers will be housed in a simple computer tool which could just sit on a smartphone,” she says. “It will be easy to use, with information available that allows growers to work out what is required for their unique growing situation.”

The data that will form the heart of the app, or whatever access system is eventually chosen, is still being gathered through Plant & Food Research – but is motivated by some huge global and national issues.

“We need to increase food production because we have a global population expected to grow by about 2 billion people in the next 30 years, so we need to produce more food for more mouths from a finite amount of land,” says Dr Brendon Malcolm, who works alongside Fraser in Plant & Food Research’s Cropping Systems and Environment group.

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We need to be more efficient with the resources we have, not only the land but with resources like nutrients and water. The soil can’t supply all of the nutrients that plants need, so growers commonly need to add more. However, it’s relatively easy to add too much, so we have to understand what the crop needs and when it needs it, both to keep the soil healthy and to not inadvertently lose nutrients into the wider environment.”

That’s where the Sustainable Vegetable Systems (SVS) project that Fraser is involved with comes in. It’s a four-year programme exploring how much nitrogen flows through the system, in particular how much remains in the system after each crop, and consequently how much is at risk of leaching – and what sustainable practices might be adopted to optimise land use and minimise the risk of environmental degradation.

Nitrogen leaching can be influenced by several factors, including soil type, fertiliser applications and water inputs (irrigation or rainfall), management practices, and the rooting depth and density of vegetables, as well as crop residues – what’s left over after crop harvest.

So the SVS project – partially funded by the Ministry for Primary Industries in partnership with the potato and vegetable industry – is modelling nitrogen uptake and losses from within nine commercial sites across New Zealand, gathering the data that will eventually help power the tool for growers. The nine commercial sites go hand-in-glove with Plant & Food Research’s more scientifically controlled trial sites in Lincoln and Hawke’s Bay. Crops under evaluation include potatoes, onions, brassicas, butternut squash and leafy greens.

“We are also trying to gather data to help growers with management techniques suited to their land, operations and situation,” says Fraser. “I am always conscious, in saying that, that it sounds like we think farmers have been doing it wrong. Far from it – we know things now that were not known in the past and we know there is not a one-size-fits-all solution.”

The need for more in-depth understanding and management of environmental impacts is something big food producers are also becoming increasingly aware of. Announced in August last year, a three-year project involving LeaderBrand Produce, Countdown and Plant & Food Research is the first industry-wide collaboration to investigate the impacts of regenerative farming practices in vegetable growing, particularly in relation to productivity, profitability, people and environment.

It is being run out of LeaderBrand’s vegetable production operation in Gisborne, with a demonstration site trialling regenerative practices and evaluating the impacts of using compost and cover crops across varied crop rotations. The trial site is running next to a control site using current management practices, so direct comparisons can be made over time.

Results from the demonstration sites can also be used to bolster the data that feeds into the grower tool development, particularly about how management practices contribute to soil nutrition over time.

The project is also focused on the role of perennial plantings in facilitating ecosystem restoration, and will engage with staff, community, and iwi to create practices that work with, and for, the wider community. The research will also help to create tools to allow vegetable growers to make informed decisions about implementing regenerative practices of their own.

“Insects play a variety of critical roles in healthy ecosystems – they can act as pollinators of crops to produce seeds and fruit, they can help to control pest insects, and help in the decomposition and recycling of nutrients, says Dr David Pattemore, an ecologist at Plant & Food Research. “We need to understand how our activities are affecting insect populations; we can’t protect those populations until we know what we’re doing that might be impacting them.

“If you think about New Zealand historically, it was almost completely covered in forest. Now, pasture and horticultural crops are probably the dominant land use type across New Zealand. Many native plants and animals thrive in and near to food production and there’s a lot we can do to protect our native insects within the farming system.

“Our research is showing that the patches of native land on the edge of a farm can be an important habitat for insects. Other factors can also be beneficial, such as having dead wood available for insect homes or planting particular plants as food or other resources.

“We’ve spoken to farmers who are really excited about restoring the native bush on their land, and this can have flow on benefits for productivity. If we take the approach of providing safe and healthy habitats for insects, we can do a lot to make our farms and orchards thriving ecosystems that can produce food for the future.”

In the end, designing frameworks for farmers to use will help produce more food, more sustainably, now and for future generations while protecting our unique flora and fauna in the face of a changing climate.

For more information: www.plantandfood.co.nz