New Research Shows Healthy, Nutrient-dense Food Relates To Growing Systems

Farming systems influence the quality of our soil, food and our health.

That’s the finding of a landmark study where Plant & Food Research Rangahau Ahumara Kai were commissioned by Kete Ora Trust to review more than 260 research papers.

The literature review aimed to assess the current state of conventional, biodynamic and organic farming systems and map out any connections between food growing systems, food nutrient density, human health and consumer attitudes.

They found evidence in the literature to suggest that the greater the soil life, the greater potential for the transfer of nutrients from soil to crops.

“The soil in which crops grow can have a significant impact on the quality of produce, including the nutritional composition.”

It goes on to say: “The general theme emerging from the literature suggests that biodynamic and organic management leads to elevated soil health and these practices generally promote more soil life than conventional growing systems.”

They found evidence in the literature to suggest that the greater the soil life, the greater potential for the transfer of nutrients from soil to crops.

“Nutrient-dense foods are important for health because they deliver more of what the body needs for good health (i.e. vitamins, minerals, complex carbohydrates, protein and healthy fats) and less of what it doesn't need as much of (i.e. saturated fat, sodium and refined sugars),” the Report adds. Nutrient dense foods support both physical and mental health.

However, it also notes there are gaps in the research of biodynamics growing practices, and what organic growing practice data there is, is variable. It also comments on a lack of multiple studies on the same crop within different systems, and research in an Aotearoa New Zealand setting.

This report showed huge potential for future studies. This vital review and themes found within will help guide research into key areas to help understand exactly which practices deliver improved soil health and how, in order to help drive improvements in nutrient density and crop composition.

Chair of the Kete Ora Trust, Sam Weaver, welcomed the findings, saying that the Plant & Food Research report is Phase One of a study that will understand more clearly the links between soil health and human health, via growing systems in an Aotearoa New Zealand context.

“What we know is that living, healthy soil and good human health are closely related, and biodynamic and organic agriculture can make a significant difference to producing healthy, uncontaminated, nutrient dense food, compared to conventional agriculture. By improving our soil health, we can improve our human health.

From this study we now need to move to further applied research to show how these differences play out in an Aotearoa New Zealand setting with local crops. Kete Ora Trust is inviting funders to the next phase of applied research, which will provide vital information for growers, consumers, policy makers, the agricultural and health sectors.”

New Zealand is at a pivot point. By taking this opportunity to further our understanding of the relationship between food quality and our growing systems we can be at the forefront of a global wave by strongly demonstrating the link to the health of our soil and our own health. At the same time, we can become a world leader in the production of truly healthy food for New Zealanders and our critical export markets,” Mr Weaver said.

Link to full report:

https://www.keteora.nz/our-work/nutrient-density-research-phase-1-report-released/

Excerpts from the Report

“Foods are a made up of complex mixtures of many macro- and micronutrients, as well as other bioactives (e.g. phytochemicals), that are essential for the proper functioning of the human body and overall good health. Nutrient-dense foods are important for health because they deliver more of what the body needs for good health (i.e. vitamins, minerals, complex carbohydrates, protein and healthy fats) and less of what it doesn't need as much of (i.e. saturated fat, sodium and refined sugars). Nutrients are needed to build all the body tissues but are also essential for many healthy bodily functions such as a healthy immune system, lowering the risk of non-communicable diseases (e.g. diabetes, cardiovascular disease, osteoporosis), assisting with weight management, improving digestion and can also lead to better mental health.”

From Executive Summary P 2

• The strongest evidence is for differences in the phytochemical composition, with significantly higher concentrations of phenolic compounds, such as flavonoids, in both biodynamic and organic crops compared to conventional crops. This results in higher in vitro antioxidant activity in these crops.

• Conventional crops have consistently been shown to have higher pesticide concentrations and higher nitrate concentrations than those grown organically (there are fewer studies with biodynamic crops, but expectations are they would confer the same advantage as organic).

From Executive Summary, p.3

“The soil in which crops grow can have a significant impact on the quality of produce, including the nutritional composition. The general theme emerging from the literature suggests that biodynamic and organic management leads to elevated soil health and these practices generally promote more soil life than conventional growing systems. The improvements in soil health includes greater functionally healthy microbial biomass, which allows plants to perform better physiologically with greater resilience to stress, meaning they have better chance to adsorb the nutrients they need to thrive with this leading to a state of ‘improved nutrient density’ overall. Underpinning soil health is elevated soil organic matter, with the microbial biomass playing a key role in enhancing the plant-availability of the nutrients in this organic matter.”

Biodynamic and organic growing systems produce healthy, living soils
Report, page 35

“At a high level, physico-chemical conditions that influence microbial communities include pH, moisture, nutrient availability, soil structure and temperature, with moisture and structure in turn influencing oxygenation, nutrient transport and gas exchange. Within each soil microbial community there will be organisms that have differing ranges of tolerance to all these factors and thus their functional traits are differentially expressed. Generally speaking, biodynamic soils – like organic soils – have better structure, higher carbon, more stable pH and moisture (Krause et al. 2022 and references therein), therefore it is likely that microbes expend less energy to maintain cellular homeostasis and more energy can be devoted to roles such as symbiosis and (luxury) nutrient acquisition (Käster et al. 2021). Coupled with better soil structure is higher amounts of oxygen which allow a predominance of aerobic metabolism, providing more energy for the microbes per unit of carbon consumed. Practices such as conservation tillage and organic carbon accrual change the oxidative potential within the soil (redox conditions), altering the energetics for biogeochemical processes including trace metal mobilisation (Husson 2013). Benbi & Nieder (2003) suggest that 80–90% of soil processes are mediated by microorganisms (see Custodio et al. 2022), but we are a long way from deeply understanding the ecological mechanisms and connections in soil.”

Report, pp. 38 - 39

“As an example of the potential benefits of the microbial biomass-derived plant growth promoting properties of biodynamic preparations, a comprehensive study comparing conventional, organic and biodynamic was published by Goldstein et al. (2019). This study reports that relative to the organic treatments, root dry matter increases associated with the use of biodynamic preparations varied from 12% to 39% and root length differences varied from 10% to 37% depending on the experiment, crop, year, and preparation application. The authors also included a biodynamic nettle- and manure-based field spray that induced substantial, positive yield compensatory effects for maize and wheat under stress condition years. The authors postulate that greater root production and root health stimulated by preparations is probably linked to greater above-ground vegetative growth, enhanced yield under stress conditions, and increased soil quality and carbon in soils.”

Report, Summary page 40

“Differences in microbial biomass of living soil in biodynamics, organics and conventional growing systems is very likely to influence nutrient density, but direct evidence is lacking and much of the soil biological science is constantly evolving and discovering new things. Despite a lack of direct evidence, strong inferences can be made with respect to how the various microbial groups specifically within biodynamic and organic systems contribute to positive plant physiological response within a backdrop of (usually) increasing microbial biomass and improved soil quality metrics. Positive plant physiological response is influenced either directly, through pathways such as changes in nutrient bioavailability delivered by bacteria and fungi in the soil or indirectly through microorganisms producing plant growth promoting chemicals or controlling negative impacts such as pathogen load and infectivity. Growing systems need to be considered through holistic examination of soil-plant-microbe dynamics, along with assessing additional layers of complexity such as animal dynamics, the influence of management practices and use of various agrichemicals.”

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