New and existing scientific research into permaculture and permaculture-inspired techniques in rice cultivation has revealed it has several environmental benefits, outweighing certain impacts created by traditional agricultural practices. Franco Vessio, co-founder of plant-based food producer MozzaRisella, reveals the findings from the company’s latest report on permaculture rice cultivation.
The report – titled ‘Research and systematisation of data on rice permaculture’ – summarises key research in this area and highlights that the technique represents “an evolution in organic farming practices”. Key factors used to determine this included a reduction in greenhouse gas emissions and the contribution to the sustainment of stronger biodiversity levels by creating more habitats.
This conclusion was reached by analysing the results of several studies in the past two decades and most recently in the last two years, including rice and plant cultivation techniques and those inspired by permaculture. Overall patterns pointed to a majority of organic farming practices favouring permaculture techniques, supporting elevated levels of biodiversity, and having a positive impact on soil quality, the diversity and quantity of populations and pollinators, and a reduction in water consumption.
Additional benefits to permaculture highlighted in the research also included a reduction in land consumption (due to using less space in a more intensive output), better results for human health due to the absence of chemicals, protection of natural resources, prevention of water shortages, less energy use due to self-sufficient system implementation, as well as a diminished risk for farmers from not having to depend on monocultural practices.
Ethical and environmental principles of permaculture
Permaculture is a relatively new organic farming technique used in rice farming and is said to help manage “social, economic and environmental aspects of sustainability” and is defined by its self-sufficient design, which assures the diversity, stability and resilience of natural ecosystems. The term permaculture was coined in the 1970s and was originally inspired by Fukuoka Masanobu, a Japanese farmer and philosopher who created a method commonly known as “natural farming” or “do nothing farming”.
In comparison to its highly conventional counterpart, permaculture does not involve heavy use of synthetic chemical fertilisers, pesticides, herbicides, genetically modified organisms and irrigation. Traditional agriculture may be deemed effective in terms of yielding short-term efficiency gains and high productivity rates, but with climate change and pollution now causing serious concerns for both the future of farming and the environment, it’s a method that is no longer environmentally sustainable in terms of resources and energy consumption.
By looking at the studies within this report, we can infer that permaculture emphasises crop diversity and the use of perennial and annual crops in addition to organic or chemical-free soil and plant management practices. However, not a lot of in-depth research has yet been done on permaculture rice cultivation, but results from these findings can still be used to advise and improve the environmental performance of both producers and suppliers.
What are the environmental impacts of rice cultivation in comparison to traditional techniques?
Different practices can help alleviate environmental impacts that are created in conventional rice production, which involve the vast application of plant protection products (primarily herbicides) and poor agricultural practices that can lead to risks to human health and contamination of natural resources.
Organic rice cultivation systems involve numerous operations that are carried out in both the farm and the field, which consider organic fertilisation, soil tillage and sowing, crop management and harvesting, and storage operations.
Before the rice is sowed, the sowing is predicted a combination of vetch and ryegrass (approx. 220 kg ha-1 of seed, 70% ryegrass and 30% vetch) and the biomass produced is incorporated into the soil in May when dry mass production is about 5 t ha-1. Organic fertilisation with compost is also envisaged (22.5 t ha-1).
In comparison to conventional rice production, the seeding rate is higher by approximately 10% due to increased mortality as a result of competition with weeds and mechanical control operations. The crop management phase is also simplified compared to conventional rice production as it doesn’t require intervention with chemicals (herbicides or pesticides) or chemical fertilisers.
The core differences between organic rice production and conventional rice production can be defined by the following categories: fertilisation, weed management, drainage of flooded fields and grain yield.
Organic fertilisation using compost is used for both production systems; however, green manure is used purely for organic rice production. The more organic matter that is input into the soil with green manure, the higher the methane emissions. Yet, using mechanical weeding, which does not require the use of agrochemicals, implies a greater consumption of diesel fuel.
When it comes to weed management, organic rice production does not use chemical herbicides but uses mechanical weeding, whereas conventional rice production does (two applications). For drainage of the flooded field, there is one aeration in conventional rice production, but none in the organic rice production scenario. The grain yield with conventional production is 8.02 ha-1 27% moisture corresponding to 6.81 t ha-1 commercial moisture.
Overall, the results of this study show that organic rice production in comparison to traditional systems, when using less pesticide application, has a better performance (-94%) due to the absence of plant protection products. In terms of environmental effects, yield reduction and different use of agronomic inputs and means, have an acute effect on environmental performance.
The future of permaculture rice farming and its pros and cons
One study in particular, which took place at Cascina Belvedere farm and uses permaculture-inspired cultivation practices by Mr Bio Food – the producers of BioSuRiceÒ (brown sprouted rice) which is the main ingredient of MozzaRisella products, alongside what other authors have concluded from their rice studies using different cultivation techniques – it’s possible to predict several environmental benefits.
These benefits include a reduction in greenhouse gas emissions due to using dry seeding and the use of intermittent flooding tailored to the needs of the crop, which limit the time period where anaerobic conditions can develop and subsequent methane emissions. Dry seeding and intermittent flooding also can be linked to a reduction in water consumption in comparison to continuous flooding, using higher water efficiency that doesn’t negatively affect production yields.
Thanks to not using herbicides, the winter cover of herbaceous plants and the ensuing mulching layer that contains weed development, it also helps reduce the negative effects on human health and ensures that the return to the environment of water is uncontaminated by pollutants.
Furthermore, soil quality is helped by nutrients that are brought through the mulching of the winter herbaceous species and the use of rice straw that is left in the paddy field and buried, which contributes to the supply of nutrients. Other greenhouse gas emissions are also positively impacted due to a reduction in synthetic products (plant protection products, herbicides, fertilisers) at least equal to those resulting from the production process, but the benefit should be weighed against any greater emissions.
There are some critical issues that have yet to be confirmed if they can be compensated for with a lower environmental impact and require further investigation regarding production yields, greenhouse emissions and eutrophication. Cultivation techniques that reduce absolute emission values can reduce the environmental benefit with extremely low production yields. Some studies show that intermittent irrigation techniques can possibly compromise production yields by up to 14-28%.
However, when it comes to greenhouse gas emissions they should be compared by emissions generated from the potential increased use of agricultural inputs in comparison to alternative techniques, the use of organic soil conditioners and mulching under anaerobic conditions during the flooding period. Due to a lack of data concerning the nutrient content of water (mainly nitrogen and phosphorous), it’s also impossible to determine considerations regarding the possible effects of eutrophication.
Overall, the majority of studies confirm that organic farming practices generally favour permaculture practices and indeed support high levels of biodiversity. Ultimately, the ecological sustainability of rice can be attainable by restoring the biodiversity of rice paddies by protecting the surrounding environment, alternative cultivation models and the lessened use of pesticides and chemical fertilisers.
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