Growing systems and approaches

Most large commercial systems are monoculture systems, meaning they grow one crop species across a large area — perhaps several hectares or more.

An alternative approach is what is known as a polyculture system, where multiple crop species are grown in the same field. This could be achieved in blocks, such as different crops in adjacent raised beds in a market garden or interplanting  (planting in between) different plants.

Historically, polyculture systems were used, in part because of the way different plants benefit each other and the wider system.

From the 1950s onwards, monoculture systems became more popular. Meanwhile, fertilisers, herbicides, pesticides, and fungicides became more commonplace. And, without the need for beneficial relationships between plants, growers could plant massive areas in a single crop and apply a fixed rate of fertilisers, sprays, and water for “efficient” crop management.

There are two distinct types of monoculture:

• Conventional monoculture
• Organic monoculture.

Conventional monoculture

Heavily tilled soil formed into raised beds, ready for planting, most likely in a conventional monoculture system.

Conventional farming

We’ll use conventional farming to refer to growing plants in tilled (cultivated) soils supported by chemical fertilisers, herbicides, pesticides, and fungicides.

In conventional monoculture systems, these approaches are applied to single crops planted across large areas.

Advantages

The biggest advantage of conventional monoculture systems is that they produce significantly higher crop yields per hectare under normal climatic conditions.

This is due to many factors:

• All the plants in a monoculture have the same growth preferences, so they are easier to manage; for instance, the same spray for pests can be used across the whole field.
• Economies of scale lead to savings through the use of:
  • bigger equipment requiring fewer staff members
  • precision agriculture technology is affordable when done on a large scale. This can lead to lower inputs of water, sprays, and fertilisers.

Precision agriculture is an approach where environmental conditions and crop health are precisely measured. The data controls how much of each input is applied to the crop. For example, using a drone to measure plant health from an optical sensor to prepare plant health maps and then using these to programme a tractor’s fertiliser spreader to apply more fertiliser to the areas where the crops are unhealthy.

Disadvantages

The main disadvantages of conventional monoculture systems are their environmental impacts:

• Nutrients leach into groundwater and make their way into the water table and underground aquifers, and waterways, making these environments toxic to the plants and animals that usually live there. This is a significant problem in Aotearoa, where, according to Stats.govt.nz, it is estimated that almost 70% of Aotearoa’s river length has more nitrogen in the water than recommended by scientific guidance.
• A reduction in biodiversity in many forms:
  • According to NZ's Ministry for the Environment:
    • Tilling the soil negatively affects soil health. This is a problem because “soil health is a soil’s ongoing capacity to function as a living ecosystem that sustains plant, animal, and human health”
    • Use of heavy machinery also leads to the "compaction of soil, which further damages soil health, as does the use of fertilisers and pesticides."
  • Habitats for migratory animals are reduced as smaller farms are joined up into large-scale monoculture systems. As a result, there are fewer beneficial animals and plants, so crops are more susceptible to pests and diseases, increasing the need for chemical control methods.
• Soil degradation from compaction and frequent tilling. Frequent tilling can also break up soil structure into fine particles easily blown away. The loss of quality soil to erosion is a significant issue. For instance, according to SoilsPortal, about 85 million tonnes of soil is lost from pasture yearly in Aotearoa.
• Depletion of water sources. Many large-scale monoculture operations irrigate their crops to increase yields. The drawback to this is that this uses a great deal of water, which must be drawn from waterways or underground aquifers. According to the US Environmental Protection Agency, depleted aquifers can lead to lower lake levels, land subsidence and the formation of sinkholes, and saltwater filling aquifers that were previously freshwater.
• Spray drift may damage surrounding plants and crops. Spray drift is when the wind blows chemical sprays onto nearby plants not meant to be sprayed.

Other disadvantages include:

• Spray residues on food crops are potentially toxic to humans if consumed in large quantities. In Aotearoa, the Ministry of Primary Industries is responsible for overseeing the maximum residue levels (MRLs) for pesticides on plant-based foods. Consumers are becoming more aware that applying toxic chemicals to food is not ideal. Those with the means are starting to buy food that has not been sprayed with synthetic pesticides, even though this costs more.
• Lower resale value. Because spray-free crops are more desirable, crops produced through conventional monoculture systems tend to attract lower values when sold.
• Risk of catastrophic loss. Monocultural growing operations carry more risk in that if their crop is impacted by pest, disease or weather events, a large portion of that crop can be wiped out. For example, kiwifruit growers were majorly impacted when the Pseudomonas syringae pv. actinidiae (Psa) bacterium arrived in New Zealand in 2010. According to Te Ara, “It had a widespread and severe impact on the local industry, costing several hundred farmers hundreds of millions of dollars.”
• Significant carbon dioxide emissions from operating large machinery.

A crop duster applying pesticides to a corn field. Corn is frequently grown in a monoculture system in the USA. In New Zealand, kiwifruit, and apples have commonly been grown that way but the trend is changing towards more sustainable practices.

Organic monoculture

An alternative to conventional monoculture systems is organic monoculture systems. These are like conventional monoculture systems but with a few modifications:

• The main difference is that organic systems use natural fertilisers and naturally occurring substances for pest and disease control.
• They may use a minimum tillage approach to propagation, where seeds are drilled into the soil without completely turning the soil over.

Advantages

Climate Change friendly. Although conventional monoculture systems produce significantly higher crop yields under normal climatic conditions, there is some evidence that organic farming results in significantly higher yields under severe drought events.

With severe weather events — like droughts and floods — becoming more frequent due to climate change, organic systems may become on par with conventional systems.

Crop value is higher. Another advantage of producing organic produce is that the crops attract higher values than those produced using conventional farming approaches.

A single growing environment. Like a conventional monoculture system, an organic system is a single growing environment. This method enjoys easier management due to:

• the crops having the same growth preferences
• economies of scale through bigger equipment
• fewer staff members
• the ability to use precision agriculture to reduce inputs.

Disadvantages

Many of the disadvantages of conventional monoculture systems apply to organic monoculture systems, including:

• a reduction in biodiversity
• soil degradation
• depletion of water sources
• business risk due to a “many eggs in one basket” situation
• carbon dioxide emissions from operating large machinery.

Organic monoculture systems for growing plants are not particularly common in Aotearoa. More often, growers will stick to a conventional monoculture system or become an organic operation more broadly, which generally means using polyculture systems.

Polyculture systems involve:

Polyculture is an overarching term for a range of different approaches to growing.

Permaculture	Here is a description from a Wikipedia contributor: "Permaculture is about creating permanent ecological and social systems by adopting a more natural approach to agriculture. The word permaculture is derived from “permanent” and “agriculture”. However, this was later revised to be “permanent” and “culture”, to include social aspects."
Organics	According to Biogro.co.nz, organics or organic agriculture: "...is more than spray or residue free. It is a holistic style of farming where the health of the soil and environment is prioritised, including the surrounding flora and fauna. Farmers provide positive environmental care by focusing on the long-term health of their land, waterways, soil and livestock rather than the short-term gain."
Hua Parakore	We can learn from Te Waka kai Ora (TWKO) that it is: "...an approach to growing that is centered in a Māori world view (Te Ao Māori). It draws on traditional wisdom (mātauranga) and practice (tikanga) to address the modern crises we face, specifically climate change, peak oil and food insecurity. It provides food security for indigenous communities through environmentally- and socially-centred practices."

More about Hua Parakore

In the following video, Dr Jessica Hutchings introduces the Hua Parakore framework.

As Dr Hutchings notes:

While Hua Parakore aligns with parts of western concepts such as permaculture, organics, biodynamics, and companion planting (more detail below), it is a truly indigenous framework. It is firmly based on relationships with nature (including people) and strengthening our connection with Papatuanuku (the earth mother) and Hineahuone (earth-formed woman and spiritual guardian of soil).

Pakeha are not excluded from becoming Hua Parakore, but their kaupapa must be consistent with and connected to tangata whenua (people of this land).

The six key kaupapa (concepts or principles) of Hua Parakore are introduced in the booklet: Te Papawhairiki mō Hua Parakore: Ngā āhuatanga o Hua Parakore: Resource 1. The principles are gratefully reproduced here. 

Hua Parakore is the Te Waka Kai Ora Korowai of Excellence for mahinga kai. It belongs to iwi, hapu and whanau of Aotearoa. Hua Parakore promotes the re-establishment of native trade and diverse, vibrant and living indigenous economies. Hua Parakore is tino rangatiratanga and held within the whare wananga of putaiao Maori and is understood through the Hua Parakore kaupapa:

• Whakapapa – Hua Parakore is a connection to the natural environment.
• Wairua – Hua Parakore maintains peace and safety.
• Mana – Hua Parakore is a vehicle for social justice.
• Māramatanga – Hua Parakore is a source of enlightenment.
• Te ao Tūroa – Hua Parakore maintains natural order.
• Mauri – Hua Parakore maintains healthy soils, kai, and people.

Hua Parakore assures Kai Atua, food that enhances the oranga and mauri of whanau, communities and consumers.
Hua Parakore is a korowai to NZSA 8410.2003 New Zealand Standard for Organic Production.
Hua Parakore honors the statements and rights contained within Te Tiriti o Waitangi, The United Nations Declaration on Indigenous Peoples Rights and the Mataatua Declaration.
Hua Parakore aligns to the ethics and aspirations of Slow Food International and Native Trade.

Source: tewakakaiora.co.nz (PDF)

As well as being a framework for growing kai using mātauranga and tikanga Māori, Hua Parakore is a validation and verification system mapped to NZS 8410:2003 Organic Production.

The process of becoming verified takes a minimum of three years, which gives time for growers to learn and adjust their processes to fit with the kaupapa. It is a learning journey, during which growers are mentored and continue to become enlightened (māramatanga).

In Hua Parakore, synthetic fertilisers and sprays are not used, nor are genetically modified organisms (lab generic engineering). Human waste must never be applied to the soil used to grow food crops.

Organics

Organics (also referred to as organic farming, ecological farming or biological farming):

Companion planting capitalises on the benefits of the natural features and structures of individual plants.

This video from GrowVeg introduces companion planting for the home or community garden:

Like with Hua Parakore, genetically engineered materials are not permitted.

Organic farming often involves keeping livestock, which can complement fruit and vegetable crops. For instance, cows and goats eat weeds and grass seed heads, and chickens produce manure used in compost and provide eggs for eating.

For the most part, organics aligns with Hua Parakore, though there are some differences. For example, in organics, composted human waste may be seen as a resource and added to garden beds for growing food.

In Aotearoa there are five organic certifiers:

• AsureQuality provides organic certification for export and for the domestic market.
• BioGro provides organic certification for export and for the domestic market.
• Demeter provides biodynamic certification.
• OrganicFarmNZ provides lower-cost organic certification aimed at smaller producers who sell only to the New Zealand domestic market.
• Hua Parakora is the world's first indigenous organic verification is a kaupapa Māori system for Kai Atua - Pure Foods.

Permaculture

It is about creating permanent solutions, so perennial plants feature extensively.

The concepts of a food forest, companion planting, and biological control of pests and weeds align with permaculture principles.

Another concept often used in permaculture is keyline design, which involves catching and using rainwater to the best effect.

This video by Possible Media provides a short overview of keyline design:

Permaculture using a keyline design is relatively low impact. It may require earthmoving machinery to form dams and waterways, but this is a one-off process. After that, it involves the establishment of perennials like trees and shrubs and after that herbs and annuals.

Advantages of polyculture systems

Some of the key advantages of polyculture over monoculture include:

1. Increased biodiversity: Polyculture systems support greater biodiversity as multiple crops are grown together, creating a more complex and diverse ecosystem. This can help promote soil health, reduce pests and diseases, and provide a habitat for beneficial organisms like pollinators and predators of crop pests.
2. Improved soil health: Polyculture systems can improve soil health by reducing erosion, increasing soil organic matter, and enhancing nutrient cycling. Different crops have different root depths and nutrient requirements, which can help to break up compacted soil and improve soil structure.
3. Enhanced pest management: In a polyculture system, pests are less likely to cause widespread damage because they are less likely to find large areas of a single crop. Additionally, some crops can repel pests or attract natural enemies of pests, which can help control pest populations without the need for chemical pesticides.
4. Resilience to environmental stresses: Polyculture systems are generally more resilient to environmental stresses like drought, extreme temperatures, and flooding, because they have a greater diversity of crops with different tolerances and requirements.
5. Increased economic stability: Polyculture systems can provide greater economic stability for farmers because they are less dependent on a single crop. If one crop fails or the market price drops, the farmer can still rely on income from other crops.

Overall, polyculture agriculture offers a more sustainable and resilient approach to farming than monoculture systems.

Disadvantages of polyculture systems

Some of the key disadvantages of polyculture include:

1. Higher labour costs: Polyculture systems can require more labour than monoculture systems because different crops have different cultivation and harvesting requirements. For example, some crops may need hand-harvesting, while others can be harvested mechanically.
2. Lower yields: Polyculture systems may have lower yields than monoculture systems because the crops compete for resources like sunlight, water, and nutrients.
3. Greater complexity: Polyculture systems can be more complex to manage than monoculture systems because there are more variables to consider, such as crop rotation, intercropping, and pest management. This can require more knowledge, skills, and planning on the grower's part.

Congratulations! You have reached the end of Module 3. You may like to review the About This Module information to assure you are on track with your assessments.