Climate Change Impacts On Horticulture
Environmental Protection And Climate Change Impacts On Horticulture
Adapting to climate change and implementing a focus on sustainability are, together, driving a shift in the horticulture industry. Growers are seeing impacts across all aspects of business, with impending environmental protection regulation and concern for water quality requiring change in farm management practices.
A growing public appetite for healthy, sustainably-produced fruit and vegetables means horticulturists are increasingly choosing to implement schemes which demonstrate their improved environmental performance to the market. Even the crops being grown may change over time, with horticulturists selecting strains future-proofed for a warmer climate or even moving into sub-tropical varieties.
Resourceful organisations, like Wholesale Landscapes, are offering solutions that help horticultural businesses mitigate the impacts climate change and increased expectations around environmental protection and performance pose. Wholesale Landscapes has a technical team experienced in providing tailormade products for your horticultural enterprise.
Changing consumer preferences can present challenges for growers. By utilising mulch, such as Wholesale Landscapes’ Forest Floor®, around plants the need for sprays containing glyphosate is reduced. Wholesale Landscapes has a range of composts designed to meet your specific needs, including FishGro® Compost, which is BioGro®-certified organic. Compost provides a great foundation for roots to quickly access much-needed nutrients and trace elements and helps retain soil moisture in dry spells.
declining water quality has been a hot topic in recent
years. The proliferation of river-choking algal blooms,
excessive plant growth, eutrophication and incidences of
unswimmable rivers reflect reported increases in nutrients,
such as nitrogen and phosphorus.1 These increases have been
primarily linked to leaching from manure and fertilisers as
farming has intensified.2
Locally, a 2016 survey of Waimea Plains groundwater showed alarming nitrate concentrations in some areas, raising the issue that regulation of fertiliser application was imminent.3 The Plains’ river soils are intensively cropped horticultural lands with operations including market gardening, viticulture, kiwifruit and pipfruit production.
The main factors responsible for nitrate leaching in horticultural systems are high fertiliser use, frequent cultivation, relatively short periods of plant growth, low nutrient use efficiency by many vegetable crops and crop residues remaining after harvest.4
According to Federated Farmers, the horticulture sector is committed to swimmable rivers and improving the ecological health of our waterways. In June 2018, the Good Farming Practice: Action Plan for Water Quality was launched. The scheme seeks to “accelerate the uptake of good farming practices for improving water quality, to measure and demonstrate this uptake, to assess the impact and benefit of those farming practices and to communicate progress to the wider public.”5
These Action Plans aim to:
• monitor soil phosphorus levels and maintain them at or below the agronomic optimum for the farm system;
• manage the amount and timing of fertiliser inputs, taking account of all sources of nutrients, to match plant requirements and minimise risk of losses;
• require storage and loading of fertiliser to minimise risk of spillage, leaching and loss into water bodies; and,
• ensure equipment for spreading fertilisers is well maintained and calibrated.
Other initiatives include those such as the New Zealand GAP, (Good Agricultural Practice), programme, which promotes safe and sustainable production of fruit and vegetables. Certification to such a scheme is necessary for supplying many local and overseas markets, so almost 90 percent of New Zealand’s commercial scale growers are certified. Increasingly growers are seeking such ‘eco-verification’ of their produce.
These programmes are operational now but remain voluntary. The Government’s push for freshwater reform looks set, however, to see increased regulation. In Essential Freshwater6 it outlined a process which aims to improve water quality within five years, including the introduction of a new National Policy Statement for Freshwater Management, altered allocation for nutrient discharge and changes to the Resource Management Act. These would likely include empowering regional councils to review consents to ensure efficient implementation, enforcement and compliance with improved water quality standards.
The Government’s recent Wellbeing Budget announced a $229.2 million investment to encourage sustainable land use. It aims to invest in projects to protect and restore at-risk waterways and provides support for farmers and growers to use their land more sustainably, by providing tools and data to manage ecological impacts of production. An additional $3.2 million will go into the Agricultural Climate Change Research Platform to support New Zealand research to help agriculture deal with the effects of climate change.
The Environment Aotearoa 2019 report7 found that climate change is already impacting New Zealand, and the effects will intensify with time. Every ecosystem is affected, and this unprecedented global disruption is amplifying many pressures already evident in our environment. Changes include alterations to temperature, precipitation patterns, wind, and sunshine. It found that the frequency of both droughts and floods will increase.
The report found that extreme rainfall is likely to become more frequent, increasing nutrient run-off and erosion risk, especially in areas with steep slopes and loose soils. Not only does erosion cause sediment to enter waterways, it reduces productive land.
The soils on
the Waimea Plains can be classified into either shallow,
light soils, (Ranzau, Maori), or deep heavy soils, (Waimea,
Richmond). They differ greatly in terms of their soil
moisture-holding capacity.8 Improved soil management
practices are the most efficient way growers can improve the
water retention of their soil.
The application of organic matter, such as Wholesale Landscapes’ HortGro® Compost, provides enriched organic carbon matter and plant fibres which maximise nutrient and water storage, prevent erosion and improve plant vigour. Evapotranspiration from the soil can be reduced by increased mulching around plants with a product like Wholesale Landscapes’ Forest Floor®; this will also cut down herbicide use. Mulching, importantly, buffers plants in extreme weather events, which are likely to occur with increasing frequency. It also reduces nutrient leaching and improves fertiliser efficacy even during projected extreme rain.
Here, at Wholesale Landscapes, we have noticed horticulturists are making a change in the varieties of plants they are growing with robust, less climate-sensitive varieties being developed to future-proof crops. We have also had requests to develop specialist potting mixes which will improve efficiency and efficacy in propagation of these strains.
Mike Chapman, the Chief Executive of Horticulture New Zealand, (HortNZ), was recently reported9 suggesting tropical fruits may be grown here on a commercial scale in the future. He stated that HortNZ is applying to have a project funded analysing future land use, including growing appropriate crops, in response to environmental concerns and climate change. The findings of such a study could prove invaluable to horticulturists nationwide.
For information on
climate change that is specific to viticulture see: http://www.wholesalelandscapes.co.nz/Tips-Advice-Articles/x_post/Climate-change-effects-on-viticulture-00063.html
For information on glyphosate see: http://www.wholesalelandscapes.co.nz/Tips-Advice-Articles/x_post/-the-fate-of-glyphosate-00041.html and http://www.wholesalelandscapes.co.nz/Tips-Advice-Articles/x_post/Weed-prevention-beats-costly-cure-00067.html
2 In 2015, 429,000 tonnes of nitrogen and 155,000 tonnes of phosphorus were applied to New Zealand soil as fertiliser. Since 1990, the annual application of nitrogen via fertiliser has increased 627%. https://www.stats.govt.nz/indicators/nitrogen-and-phosphorus-in-fertilisers