When promoting policies that support and stimulate organic agriculture, one common criticism is heard: that organic agriculture lacks the potential for scalability; that, in spite of its environmental and social benefits, it is unable to ensure enough food production for everyone in the world to be fed. While there’s a mainstream assumption that organic systems of food production result in lower yields, there is a couple of corresponding questions that, being hardly mainstream, are hardly ever are answered: Are the world’s soils already producing food at maximum capacity? Does our current food production reach the levels required to feed everyone? The answer to the first question is negative, and the second is positive. The world is already producing enough food to feed everyone, and the world’s soils are not producing as much food as they could. This last answer to that first question is, in fact, one of the strongest arguments in favor of worldwide adoption of organic agriculture – especially in the world’s poorest regions. Organic tomatoes grow using traditional zaï techniques in the village of Vathaba, Guinea, where a serious problem of chronic malnutrition affects up to 40% of the country's population. Not only is the claim that organic agriculture gives lower yields an oversimplification (on which crops? In which regions? During which periods of the year? Using Integrated Pest Management techniques or not?), but it is an outright wrong claim in zones of the world. Nearly fifteen years ago already (in 2007), a study by the University of Michigan found that, by reducing the average input costs, stimulating soil preservation and formation, and using nitrogen-fixing Bacteria cover crops in crop rotation, organic agriculture could rise the agricultural yields in developing countries by 80%. In a world where enough food is already being produced but not enough food is being distributed, increasing food production in the areas where it is most needed could provide a basis for eradicating hunger, one of the Development Goals of the Millennium. It could also bring a lot of economic benefits to producers in those same developing countries, by reducing their expenses and increasing the economic benefits that they extract from their land. The FAO speaks along the same lines, though giving a lower estimate (that it’s still significantly higher than the present distribution): Conversion of global agriculture to organic management, without converting wild lands to agriculture and using N-fertilizers, would result in a global agricultural supply of 2640 to 4380 kcal/person/day. Sustainable intensification in developing countries through organic practices would increase production by 56 percent.

Seen from the outside, agriculture may seem to be a magical process: things are planted in the soil, cared for during a season, and food is harvested eventually: from useless dirt, the world is fed. But when farmers go into their fields and harvest the year's crop of wheat, peppers, or watermelon, they know that they're not creating food out of anything. They know what came into their field (the work they put in, the bio-manure they brought as fertilizer, the insecticides they introduced for pest control), and understand that agriculture is not an operation of creation but of transformation. Food does not spring out of the ground: raw resources are transformed into food through a lot of work, and a lot of brainpower. And the root of this transformation happens within the plants themselves, who take nutrients from the soil and energy from the sun and support seven billion people and the whole of life on earth. But plants were not made by human beings: they appeared through natural processes millions of years before the first mammal even stepped a foot on our planet. As such, they are regulated by processes that were not made by us; we human beings merely channel and instrumentalize those processes to feed ourselves. Same as the natural processes underlying soil fertility, water availability, nutrient retention, soil structure maintenance, pest control, and even seed saving: all of them were active way beyond human beings began harnessing their power for their benefit. The basis of agriculture is, thus, ecology; the principles and processes that guide how ecosystems work. There is no agricultural activity that is not based on ecological processes: there is just agriculture that is consciously based on them and that, as such, becomes sustainable, and agriculture that unwillingly goes against ecological processes and, as such, is unsustainable and leads to hunger crises and environmental troubles of all sorts. Organic agriculture is agriculture practiced through the most scientifically-informed techniques for managing agricultural land as an ecosystem. It is a system of practices that collaborates with, rather than fighting against, the very natural processes that gave origin to live on earth — as such ecology is another of its principles, alongside health, fairness, and care. In fact, it might be said to form the basis of them all. A quick glance at the myriad natural processes underlying soil degradation, which organic agriculture takes into account to prevent the loss of fertile soil, gives a good impression of the connectedness of agriculture to ecology as one of its foundational principles.

According to a recent study published by a team of researchers from the universities of Westlake and Copenhagen, it turns out that flowers can range from outright necessary to very useful in maintaining a steady supply of predators for the control of plagues in agriculture. Flowers and floral products (which includes pollen and sugary water, used as a replacement for nectar in the absence of actual flowers) greatly help increase the survival rate, longevity, and fecundity of predatory and parasitoid insects, according to a review of 628 trials done across seventy different other studies. In short: the introduction of flowers in monocultures is a decisive step in establishing a conservative system of biological pest control; a system of control agents that remain, survive and reproduce in the fields where they are released. In order to effectively introduce flowers and floral resources, some methods offered by the authors from existing literature include planting floral strips that cross monocultural fields, the application of a spray solution consisting of a mixture of sugar and pollen, and the selection of flowering species that are specifically suitable to sustain the desired predators without serving to increase the pest population. Not only did this affect positively biological control agents that are not predatory during a part of their lives (such as hoverflies and lacewings, that become nectar and pollen eaters upon reaching adulthood, and as such depend on flowers to complete their life cycles and reproduce within the field), but it also benefits lifetime predators such as spiders and ladybugs, which can feed on floral products when prey is scarce and are far more abundant in floral strips and their vicinities. A perennial flower strip in the Netherlands, at the border of an arable field (photo courtesy of the University of Amsterdam). All of this points out the need for experimentation and further study to determine the best flowering species for each individual case, and in general to test the inclusion of more flowers in the fields. Furthermore, this seems to make a stronger case for companion planting, a severely understudied area of agriculture and the subject of our upcoming articles. In short, definitely, a study that's worth a read.

Whenever a good is produced (let's say, an airplane, a coffee cup, or, for the agricultural sector, a pound of tomatoes or a single tomato) the process of production itself has consequences for the whole of society. This means that a whole lot of people who didn't agree to be involved in the consequences of that production receive the consequences of the production nevertheless. The name that economists have for that burden is an externality, as in the externalization of a cost: you take the whole of the benefits, and somebody else (or everyone else) pays part of the costs. A good example is in the unrestricted usage of inorganic fertilizers. Someone may consider it cheaper to go above and beyond with their fertilization, just to make sure the soil is really soaked with that sweet nitrogen, and they'll certainly reap the benefits for that in the form of a high-yielding harvest. But after the first rains of the season, a good deal of those nitrogen-heavy fertilizers will wash up to the closest bodies of water, and they'll become everybody's problem—everybody but the farmer's, or everybody and the farmer's at the very least. A whole community that doesn't directly profit from the actions of the farmer still has to pay for part of the costs that derive from his business. That exactly is what has been happening in the whole world, but scientists and economists have only recently begun to calculate the impact of the many externalities of agricultural production as a whole (such as in the impact on the water quality of the United States, for example). For organic agriculture in particular, a calculation of the actual externalities of traditional practices of farming could mean a complete revolution in the market. With the increasing popularity of carbon taxes (between 2005 and the present, nearly 50 new initiatives for carbon taxation have passed in places as diverse as Australia, South Africa, the European Union and China), a 2020 German study by a team of researchers from the universities of Munich, Greifswald and Augsburg that suggests reverting the payment of externalities to agricultural producers could begin the process towards tilting the market share in favor of organic produce. Though currently held back in their competition against non-organic foods by the lower prices of these, an internalization of the agricultural externalities of traditional food production could result in something like the following graph (fig. 2 in the article): The cost of conventional foods could rise as high as 146% for meat, 91% for dairy and 25% for plant-based produce. Even if LUC (land-use change) surcharge were eliminated, organic produce would still be cheaper overall. But wouldn't this increase in the prices of food revert ultimately to the consumers? What would happen to meat producers? And why can't we just keep at it with our current system? From these questions, the last one is the easiest to answer: these are costs already paid by the government, and indirectly by the taxpayers. As the cost of dealing with these unaddressed externalities rises (as rivers get more and more polluted because farmers keep spraying their fields with inorganic fertilizers, as they believe the government will have to clean it up), these will have to be paid by someone, and the fairest way would be for the polluter to pay them. As for the first two, why not read the article? After all, it's right here.

It would seem counterintuitive that emphasizing nature would foster deeply human values – at least, from the perspective of human beings as different or separate from the natural world. This is the perspective of most of the modern agriculture, one in which the soil is there to be exploited for the production of food, and only secondarily and for that purpose it is fed inorganic nutrients in large quantities; large enough to overflow with them and send those nutrients into rivers, ponds, and seas. A study from the University of Nebraska-Lincoln, however, suggests that behind alternative practices or agriculture lies an altogether different set of human values. In Empathy-Conditioned Conservation: "Walking in the Shoes of Others" as a Conservation Farmer, a research paper published by the University in 2011, researchers found that the main motivation behind adopting tillage conservation practices among farmers was an unexpected one: empathy. As this early summary of the research indicates, even though a potential increase in profits, the education received by farmers and the financial support of the government were counted among the variables that influenced whether the farmers adopted conservation tillage practices, a change in these influenced the probability of adoption by around 1% or less. In contrast, having an empathetic mentality (which the authors describe as “tempering the pursuit of self-interest with shared other-interests”) was the single most influential variable, increasing by around 10% the probability of adopting these techniques. The Blue River in Nebraska, looking downstream. The farmers that take care of the lands on the margins of this river formed the basis for the study's sample. The study, which used as a sample the farmers around Nebraska and Kansas, in the United States, that had lands surrounding the Blue River, found that empathy played a role depending on how much the farmers regarded that leached soil and nutrients, coming from lands managed without the adequate conservation practices, affected their neighbors downstream. When farmers realized how their neighbors downstream were being affected negatively, the majority of them received a strong motivation to implement conservation practices, which in some areas led to an adoption of no-till or low-till management schemes is up to 90% of all farms. To the authors, this is evidence of how “farmers pursue a joint and interdependent own-interest and not only self-interest as presumed in microeconomics”. To policymakers, it should make one thing clear: deeply human values such as empathy are key for the widespread adoption of organic agriculture, as a responsible and sustainable way of producing food for the world. Though economic benefits are certainly a motivation to switch to organic land stewardship, there are otherwise neglected benefits and values that must be brought into the calculations underlying a massive adoption of organic agriculture.

Every year, millions of gallons of synthetic pesticides are applied to crops worldwide, with a well-known negative effect on the quality of the final product as well as on the quality of the surrounding ecosystems. The reasons behind their intensive use are the same behind the usage of synthetic fertilizers: convenience (real or assumed), a lack of viable alternatives, and a strong cultural and educational bias in favor of their use. But this is all changing, and changing fast, with the diversification and massification of biological means for pest control: in a 2017 paper, a team of researchers from the Netherlands, Belgium and Spain found that while the synthetic pesticide market was consistently growing at a yearly rate of 5-6%, the biological control market was exploding at yearly growth rates of 10% before 2005, and 15% afterward. In light of these recent developments, it’s important to get an introduction to the three fundamental forms of biological pest control: classical techniques, augmentative techniques, and conservationist techniques. In each of these three techniques, a species or a group of species is deliberately released in a cropland area to serve as predators of another species, which is acting as a plague. The real variations come from the details. Classical techniques of pest control have been used since the 19th century at least, when the famous American entomologist Charles V. Riley saved the blossoming citrus industry in California from a plague unwillingly imported from Australia (the scale insect Icerya purchase) by willingly importing a predator from the same country, the vedalia ladybug (Rodolia cardinalis). These classical techniques consist in basically this: importing and establishing a foreign predator to deal with a foreign pest. Riley introduced the ladybugs in 1872, and this sight became common in citrus plantations across the state: Augmentative techniques are different, in the sense that they do not seek to establish the predator that is imported as a means of biological control but simply release it in numbers that are large enough to destroy or severely reduce a plague in a determinate moment. Consequently, these augmentative techniques (augmentative precisely because they seek to simply augment the number of predators for a while) are often repeated in regular schedules, much like in the way that seasonal applications of synthetic pesticides are carried out (but still without the many negative effects of such pesticides). The species introduced here as biological control can be foreign or local. Augmentative techniques, however, have one important flaw: they tend to work less well in ecosystems that lack diversity, as most agricultural spaces are. Another team of researchers, this time from Cornell University, noted in a 2019 paper that the efficacy of such methods is greatly influenced by the biodiversity of the areas where they are applied. Conservation techniques of biological control become the solution for these problems, as well as for the repeated cost of releasing predators seasonally. Acting from the standpoint of integrated systems management (seeing agriculture as not the exploitation of space and resources, but as the task of stewarding a system that produces food according to certain inputs, and to the management of certain variables), these techniques of biological pest control try to improve the overall suitability of the ecosystem where the predators are released, in order to allow them to get fully established and working year-round, ideally without a need for further introductions. The need for increased biodiversity in the fields is also tied, perhaps not surprisingly, with the current lack of diversity in the food we grow. Biological means of control are not new, but they are being newly introduced to many farmers and spaces where and by whom they haven’t traditionally been used. Like in conservation techniques for their management, the economic ecosystem is full of opportunities for their establishment, and, consequently, for their growth. So it’s about time we all got acquainted with the critters and microorganisms that save the food we eat – and that’s what we’ll be talking about, in upcoming entries. To cite van Lenteren, Bolckmans, Köhl, Ravensberg and Urbaneja from their 2017 paper referenced above: "Too often the following reasoning is used to justify the use of synthetic pesticides: agriculture has to feed some ten billion people by the year 2050, so we need to strongly increase food production, which can only be achieved with the usage of synthetic pesticides. This reasoning is simplistic, erroneous, and misleading. Simplistic because it ignores a multitude of other approaches to pest, disease, and weed control that we summarize below under IPM, erroneous as sufficient healthy food can be produced without synthetic pesticides (...) and misleading in that it minimizes the importance of a well-functioning biosphere and high biodiversity for the long-term sustainable production of healthy food for a growing human population (...). This short-sighted mercenary attitude might actually result in very serious environmental problems in the near future (...). A more sensible approach to food production is to ask ourselves: (1) how can we create a healthy and well-functioning biosphere in which biodiversity is treasured instead of strongly reduced, both because of its necessity for sustainable food production and maintaining a hospitable biosphere for humans (utilitarian approach), as well as because of our ethical responsibility (ethical approach), (2) how can healthy food best be produced in this well-functioning biosphere, and (3) what kind of pest, disease and weed management fits in such a production system."

Around the world and throughout history, slugs are one of the most enduring and pervasive pests that plague plant cultivation. Slugs cause damages not only to crops, but to pastures, gardens, and, in some regions, even fruit tree plantations, resulting in around 60 million dollars in yearly damages in the United States alone. In the UK, that number ascends to 100 million sterling pounds, and with the potential expansion of the Spanish slug (Arion vulgaris) and other invasive slug species threatening the world's agriculture, those numbers could go much higher. To make things worse, the methods used until now to reduce slug damage have increased soil degradation, ultimately working against growers' best interests. A chapter of the Handbook of Vegetables Pests, published by Academic Press in 2001, recommends for example a finely textured or compacted soil, regular tillage, and the lack of residual organic matter (i.e. mulch) as means to prevent an expansion of the slug problem; all of the methods that also produce soil exposition to environmental degradation. The discovery of a biological means of control for slugs was, consequently, a major advantage for agriculture. Phasmarhabditis hermaphrodita, the main agent for biological control of slugs. Enter the humble nematode Phasmarhabditis hermaphrodita, only adequately studied in the 1990s, and now commercialized around the world as a safe and effective tool for slug control. Phasmarhabditis hermaphrodita is a tiny nematode of barely less than two millimeters long (often visible only with a microscope) that enters into the bodies of slugs and parasites them, producing between 200 to 300 other nematodes in the process. Between the introduction of the first nematode into the body of the slug and its ultimate death, a period of 4 to 21 days follows in which the slug will feed gradually less, and at the end of which it will crawl into a secluded space before dying. The nematodes keep acting and reproducing throughout wet or dry weather, as long as slugs are active (especially when they are active, in fact!). These biological control agents such as pesticides and insecticides also fulfill one of the main conditions to qualify as such at a large scale, which is not becoming an invasive pest itself. Fortunately enough for growers, Phasmarhabditis hermaphrodite has also evolved to target only molluscs, and as such does not attack earthworms, insects, birds, spiders or humans. AGENT PROFILE Common name(s): Phasmarhabditis hermaphrodita, commercialized under the name Nemaslug® . Often-used species: Only the mentioned above. Type of predator: Not predatorial, parasitic. Potential damaging effects: Against non-damaging or beneficial freshwater snails; as such it should not be used near bodies of fresh water. Interesting literature on its usage: A general review on its usage and effects (2009), a brief study of the species in the scientific journal Nematology (2019), on the possibility of similarly useful species existing (2019), a case study on its effectivity on two slug species (2002).

Trichoderma fungi are an efficient, cost-effective, and selective means for the biological control of fungal diseases, bacterial diseases, and even nematodes, as through their own growth they outcompete, parasite, and create resistance in plants against damaging pathogens. Rather than being an agent of biocontrol, they conform a genus out of which around 25 species serve as agents individually or in distinct combinations, and all of the 25 species are used around the world as a weapon against the over 10,000 species of fungi that produce economically significant damage in crops. Together, Trichoderma fungi species constitute around 90% of the fungal species known to serve as anti-fungal agents in agriculture, and they form the basis for around 60% of the fungicides of biological origins currently available in the market. Trichoderma harzianum, one of the most widely used species of Trichoderma fungi, seen growing from spores under the microscope. Possibly the greatest strengths of Trichoderma fungi are both their capability to establish themselves permanently in an agricultural setting that is capable of sustaining fungal life (outlining once more the importance of integrating conservation techniques of biological control into the whole equation) and their incredibly wide range of techniques to combat fungal and bacterial plagues as well as nematodes. Trichoderma fungi act either directly against pathogens by mycoparasitism (parasitism of one fungus on another), aggressive competition and generation of antibiotics, or indirectly by improving the health of the plants that serve as their hosts, thus making them more resistant to pathogens (weakened as well through the more direct action of Trichoderma fungi). All of this makes them incredibly useful, dual-purpose creatures that at the same time increase yield, vigor and nutrient absorption as they combat disease and ensure a better overall health of the crops. Trichoderma fungi are also mycorrhizal fungi, and as such they present all the benefits of mycorrhizae. Above, a comparison between root systems not inoculated and inoculated with Trichoderma harzianum. AGENT PROFILE Common name(s): Trichoderma fungi. Often-used species: Depending on the region, species used are often non-native. Type of predator: Non-predatorial (parasitic at most). Potential damaging effects: On crops of edible fungi, such as Agaricus bisporus. Interesting literature on its usage: A general but very detailed overview on these fungi and their usage (2020), a general review of their usage alongside other fungi (2020), a review of their biocontrol mechanisms (2004), a study of their working alongside mycorrhizae and other fungi against nematodes (2020), divulgation material on their usage (2016).

The crown jewel of biological pest control, Bacillus thuringiensis is a species of bacteria that has become one of the most frequently used (if not the most frequently used) biological insecticides around the world. Its insecticide properties appear when this bacterium (bacteria is the plural) enters the phase of its life called sporulation, in which bacteria turn into something similar to spores by dividing within their own cellular walls, with one part of those who have divided consuming the rest and entering into a dormant state. This behavior is triggered by environmental factors like drought or a lack of nutrients available, which is often the case when Bacillus thuringiensis is applied artificially on a field. As part of that process of sporulation, these bacteria produce a certain type of protein that interacts with the gut of insects who have consumed leaves or stalks that were inoculated with Bacillus thuringiensis: the insects eventually have their whole digestive systems disrupted, eventually stopping eating and dying of hunger. This can happen as soon as a few hours after having consumed the inoculated plants, or take as long as a few weeks, according to an estimate of the National Pesticide Information Center of the US. These little creatures have saved millions of people from famine, among other achievements. Bacillus thuringiensis is an absolute juggernaut of biological pest control, targeting pests as diverse as moths (tent caterpillars, tomato hornworm, date moth, flour moth), nematodes, beetles (such as the Western corn rootworm, Diabrotica virgifera virgifera), mosquitoes, and fungus gnats. Furthermore, it does all of this while respecting beneficial insects such as bees, butterflies, or other biological control agents such as lacewings or predatory wasps (because none of these consumes enough plant matter to contract a Bacillus thuringiensis infection), as well as being safe for human beings. AGENT PROFILE Common name(s): Bacillus thuringiensis. Often-used species: Single species, with subspecies used to target specific pests (such as Bacillus thuringiensis israelensis for mosquitoes). Type of predator: Non-predatorial (parasitic). Potential damaging effects: No significant ones registered to date. Interesting literature on its usage: A fact sheet on Bacillus thuringiensis, from pages 109 to 113 (2020), use against mosquitoes (2020), use against nematodes (2003), against fungus gnats (2001), a detailed paper on how the bacterium functions and its derivative use in non-organic, transgenic agriculture (1998).

In past articles of this series we have covered with certain detail the thirteen micro and macronutrients that all plants need to survive and grow, as well as some traditional (inorganic and organic) methods of adding nutrition to the soil. The only question that remains for now is: how can the availability of these nutrients be assured? That is, how can growers ensure that, should they be unable to fertilize their fields for one growing season (let’s say), the land will not become a barren, inhospitable, infertile space? The answer to this lies in taking notice of other factors behind the measurable presence of nutrients in the soil. If a landscape is always in need of repeated fertilization to remain productive it is already in a very precarious state, in which most of the fertilizers are probably consumed during a growing season and the soil is, otherwise, inhospitable if not intensively managed. The only way to responsibly address this is to start building the soil, and here we will focus especially in two aspects of this: soil pH, and water content. All of the nutrients that we have talked about becoming more or less available according to the acidity or alkalinity of a soil. Soils that are more acidic have less availability of calcium (Ca) and magnesium (Mg), because these chemical compounds become less mobile and plants have more difficulty absorbing them. At the same time, iron (Fe), manganese (Mn), and zinc (Zn) become far more mobile and available to plants, while phosphorus (P) becomes more available at first and later is almost completely immobilized. An increase in alkalinity (that is, an increase in pH levels) reverses these processes. This is why the pH of the soil is a critical condition to be balanced and preferably adjusted to the requirements of most crops (6.0 to 7.0, but it may vary depending on the species). Here's a full pH scale, so we can contextualize that: And here's a table depicting the availability of most nutrients and micronutrients according to soil pH, courtesy of Wikimedia Commons: The water content of the soil is another major component, simply because it makes every chemical substance within the soil more soluble. Even though plants use water for other purposes as well beyond nutrient absorption, if we focus only on soil fertility it is, by itself, evident that constant presence of ideal water levels is essential for plants to actually be able to access the nutrients present in the soil. Same as with pH levels, the thirteen micronutrients and macronutrients may all be present in perfect amounts, but these two conditions deeply affect whether these nutrients are in a state that is actually useful for plants and, consequently, their keepers. Water content is measured in the percentage of water out of the total weight of a sample of soil, with results that may look like these excellent diagrams from the North Carolina Extension Gardener Handbook: Improving these two conditions passes as well through managing other chemical, physical and biological conditions of the soil, so keep an eye in our blog for future articles on those subjects. In the meantime, happy growing!