-Dr Blair Miller – Group Manager Environmental Research, Lincoln Agritech

Government recently issued a call of action to the country, saying that we must work to double our primary production export earnings while maintaining or improving water quality. To most people, this twin challenge will seem contradictory. Yet we are capable of fulfilling both of these duelling ambitions. In fact, the fight to attain them is one that we must fully commit to.

I believe we can do it, as we have some of the best scientific minds in the world on the case. But we need to utilise our experts so we have the best chance of balancing economic development with environmental protection.

Achieving export growth means developing new markets and these markets will be increasingly judging us on the integrity of our production processes. If we allow environmental impacts to worsen, we risk damaging the reputation on which our primary sector exporters trade. In other words, the Government’s challenge is not contradictory. Positive economic development must be based on sound environmental outcomes.

Pundits regularly promote the notion of moving up the value chain to increase export earnings. This, of course, is happening all the time and we should applaud companies like Synlait with their slogan, “Making more from milk”, which describes the strategy very well.

However, we must look at how much primary produce we need to achieve growth. Bulk commodities dominate primary sector exports and this will continue for the foreseeable future, so increasing production is the only realistic way to double our primary export earnings. 

However, this means intensification, and with that comes environmental impact. We need to understand this impact if we are to develop strategies that will tackle it. The fate of nitrates attracts the most attention in this area due to dairy intensification.

Phosphorous and sediment, which are pollutants that predominantly come from surface runoff, also degrade water quality. But without minimising their importance, we already have a better understanding of these. While we must keep developing strategies to deal with them, nitrate management needs greater resourcing to meet the Government’s challenge.

Nitrate leaching from cow urine patches is a major contributor to groundwater contamination. Soil scientists will need to continue working to solve this issue, but farming system changes also need further attention. We have to be careful not to jeopardise our integrity of production with too large a swing to the confinement of dairy cows, which could create negative sentiments in some markets.

If research is sufficiently funded, it will lead us to a balance between on-pasture and off-pasture dairy production and we will see more use of hybrid systems. It’s encouraging that Dairy NZ and Lincoln and Massey Universities are starting to challenge the ‘one size fits all’ approach to dairy farming and investigate alternatives to pasture based production.

It is important to invest in research that will help improve production systems, retain nitrogen in the root zone and reduce other contaminant transfers. However, to meet the production target, we can’t simply maintain our current water quality. We have to find more mitigation capacity. 

The nutrient budgeting model, OVERSEER, contains tools to analyse the likely outcomes of different management options. It is not perfect, but offers significant value, which will continue to improve with further investment. One of its limitations is that it does not deal with the fate of the nitrate once it leaves the root zone. The transport and transformation processes in the area between the roots and groundwater systems have not yet received the attention they need.

The groundwater system is highly complex, and modelling its processes is extremely difficult, but necessary if we are to fully understand how they work. The problem with making decisions before completely understanding the processes involved is that nutrient limits may be set too low, potentially limiting production in areas which could actually operate safely at higher intensities.

Land use planners need more information, as they must make some tough decisions about the appropriateness of farming activities in certain locations, and about where resources should be focused. The only way we are going to achieve the Government’s challenge is by improving our ability to choose an appropriate land use for any parcel of land.

No one scientific discipline will solve the problem; it will be the summation of a wide range of work.  Lincoln Agritech is working to develop tools and knowledge for all stakeholders involved in this debate.

Two of our large collaborative research programmes which include ESR, Aqualinc Research, Lincoln University, Landcare Research and Plant and Food Research are investigating aspects of nutrient transport and assimilation in the environment below the root zone.

We are also preparing to commercially release a low-cost, high-accuracy nitrate sensor that researchers and land managers can use to better understand nitrate dynamics.

With more work, we hope to use our developing technology and scientific understanding to help farmers directly measure their nitrate losses and this will complement the current modelling approaches. In many situations, this will reduce the level of uncertainty with the current modelling method to enable better decision-making.