Let's talk about Sustainable Agriculture

Nov 02 • Nicky Redl

sustainable agricultureWhen asked where our groceries come from, most of us might as well say they grow on shelves. We do little more than pay for them at the checkout. However, people working in the agricultural sector often spend their entire lives growing the produce that feeds the rest of us, and they are a lot more aware of the challenges that lie ahead. Food security is going to become an ever-greater issue that needs to be tackled as a community. Scientists are predicting that climate change will lead to serious food security risks, because of the increasing occurrence of droughts and floods. It is therefore important to focus on agricultural methods that can feed growing populations around the world even in challenging environments. But what produces the highest yields in the short term is not always the best answer in the longer run. 

Conventional agriculture


Conventional agriculture has led to massive increases in production capable of feeding more people. This was driven by the use of fertilisers and pesticides, and the introduction of monoculture practices where only one single crop is grown. It usually allows for the use of larger and more efficient machinery. However, the gains also come with problems that have only become apparent over time. Monocultures deplete nutrients in the soil as the crop keeps absorbing the same ones year after year, and no other plant matter is added back to the earth. As a result, more artificial, and costly, fertilisers are needed to offset this effect. Such fields also become more susceptible to certain pests and plant diseases, as they can get comfortable feeding on the same crop year after year. This means you also need to use more pesticides to make the practice work.




Increased use of fertilisers and pesticides can mean residues are washed into nearby areas. Run-off from farms close to the Great Barrier Reef, for example, has been shown to harm coral. “Recent work on contaminants such as agricultural pesticides has demonstrated that several reef foundation species are highly sensitive to acute exposure of herbicides,” according to the Australian Institute of Marina Science. “The potential build-up of contaminants can weaken the health and resilience of corals and other organisms, making them more susceptible to disease outbreaks or climate impacts.” Pesticide residues can also end up in groundwater. Research by the Budapest-based Agro-Environmental Research Institute on pesticide levels in ground and surface water in Hungary, for example, found a high proportion of water samples were contaminated.

The Hungarian Plant Protection Service has analysed about 2,000 surface water samples between 1994 and 2000 and found 5–50% of the samples containing pesticide residues, according to the research published by the Journal of Chemistry in 2015.

Other issues come with the loss of hedgerows. To make way for the large, even fields that are typical for monoculture farming, the trees and bushes that used to formerly separate smaller fields are removed. This makes harvesting with large machinery easier. However, it also increases these areas’ vulnerability to soil erosion, as strong winds are not broken up, and there no roots to bind the soil to keep it in place. As most nutrients are found in the top layer of the soil, erosion can lower productivity and in extreme cases even cause desertification. According to ecologist Gerry Marten, desertification in the south of Mexico, for example, is a result of various unsustainable land practices, including monocultures. He wrote that the Green Revolution brought chemical fertilizers, but the associated increase in crop yields went hand in hand with erosion and soil degradation, meaning that ever-high amounts of fertilisers were needed at great cost.






“Depleted soils and high fertilizer costs forced farmers to abandon their fields, extending their agriculture into newly clear-cut lands,”Mr Marten wrote in his article ‘Fighting Desertification with Community Reforestation and Sustainable Agriculture’.



“Deforestation and erosion accelerated, and today the region suffers one of the highest rates of erosion on the planet,” wrote to Mr Marten. Such extreme effects can drive farmers from their land in search of other ways to survive. “Degradation of agricultural lands in Mexico can contribute directly to cross-border migration via its impacts on household incomes in the agricultural sector,” according to the study ‘Land degradation and Desertification’ published by the European Parliament. “As poverty is a major determinant of migration, environmental degradation may be seen to influence migration through its impacts on poverty in the agricultural sector,” the study said.

The use of pesticides together with intensive farming has reduced bee populations over the years. This poses a major problem for the agricultural industry, as bees are the only way many plants are pollinated. Professor Dave Goulson, a bumblebee specialist at the University of Sussex, told Deutsche Welle that intensive farming means that the cultivated crops only flower for a few weeks a year, leaving bees to starve the rest of the time as the usual wild flowers and broader variety of plants have been mowed down to make space for farmed crops.



“In China in particular they use terrifying amounts of pesticides, and farm in a very intensive way. There's very little wildlife left at all in some area,”Goulson told Deutsche Welle.



Many farmers in the country are now forced to use a brush to pollinate flowers by hand. “In these apple and pear orchards there aren't any bees, and hence they have no choice. They either get no crop or they pollinate it themselves,” Goulson said. In addition, the deforestation to make way for intensive farming further contributes to global warming, because trees absorb carbon. The less carbon our forests absorb, the more goes into the atmosphere. And, the less oxygen is available to us. According to the NC State University, “one large tree can supply a day's supply of oxygen for four people”. 



Looking at solutions


However, you would have already heard plenty about the doom we all face, so instead of looking only at the problems, let’s look at the plentiful solutions. Intensive farming has done much to feed more people, and agriculture is a sector that is at the very centre of our survival. But we need to learn to produce food in a more sustainable manner that doesn’t deplete the soil to such a degree that those coming after us can no longer look after themselves. This brings us to sustainable agriculture.

In a nutshell, sustainability means to meet one’s needs without compromising future generations’ ability to meet their own needs.

It refers to farming practices that improve soil health while protecting the surrounding flora and fauna from negative impacts, such as from intensive fertiliser and pesticide utilisation. It also means treating resources with care, such as water. As so often, economic incentives help to promote change, so consumers have to get more involved. In some countries, this is already happening.

Consumers increasingly care where their food comes from and demand more information about origin, production techniques and how far the food has travelled (i.e. how much fuel was used) before landing in supermarket shelves. In Denmark, for example, the government is proposing to oblige manufacturers to indicate the climate impact of each food item for sale. When it comes to the agricultural practices themselves, there are various approaches to producing high yields sustainably. Rob Williams is an Australian research agronomist who has been working with subsistence farmers in Timor-Leste for 16 years, for the Australian-funded Seeds of Life programme and now AI-Com (Agricultural Innovations for Communities). He said adding rice hull biochar, which is won by burning rice hulls, has proven to have noticeable effects. Rice hulls are a waste product that is left over after rice is milled.


“You can almost double the yield of non-rice crops after burning the rice hulls and putting them back on the fields,” Mr Williams said.



“It’s using a waste product to produce more food, which is a plus.” Improving yields in a sustainable manner is the only option in Timor-Leste, because local farmers either reject fertilisers or cannot afford them, and large machinery also isn’t in use. Apart from adding biochar, another successful method to increase yields in Timor is to grow velvet beans together with corn. “Velvet bean is a cover crop that grows amongst corn. It smothers the weeds and adds nitrogen to the soil,” Mr Williams said. “Legumes add nitrogen, and they double the corn yields on the south coast. It also reduces the amount of time farmers have to weed their crops,” he added. “That’s a wonderful sustainable system.” Higher yields don’t help much though if insects and rats eat a third of your produce. “On farm losses can be as high as 30 or 40 %, and the biggest problem is weevils,” Mr Williams said.






convert old fuel drum into storage containers

Old fuel drums can be converted into storage containers

Good storage solutions are therefore an important aspect of sustainable farming in developing countries. “Australians have this all sorted because they have big silos, but in developing countries like Timor, good storage is overlooked.” An easy and effective solution is converting old fuel drums into airtight storage containers, which keeps corn away from weevils and rats. “As one farmer told me: If I have the drum and can keep my corn, it makes farming worthwhile,” Mr Williams recalled. Selecting high-yielding seed varieties also helps farmers to harvest more from the same space. What also needs to be taken into account these days is seeds’ resilience to changing temperatures. Mr Williams said that reliable measurements starting in the 1940s show that the temperature has since increased by 0.8 degree Celsius. While this doesn’t sound huge, it is already affecting the country’s coffee crop. Arabica coffee needs a cool environment and this has limited the areas where it can be cultivated.

“Previously you would grow it at 500 metres elevation, and now you might not do it below 700 metres elevation,” Mr Williams said. Other crops have not yet suffered such severe impacts by climate change, and efforts to increase yields through seed selection and agricultural practices have successfully improved the lives of countless families in the country. But not only farmers in developing nations benefit from crop rotation or mixed cropping. Growing beans to improve yields and soil health is something Australian farmers are very familiar with. Many cane growers, for example, grow peanuts, navy beans, mung beans and soybeans to break up the cane monoculture, deterring pests and reintroducing nutrients in the process.




This is also an important concept when it comes to livestock. Overgrazing can render pastures useless, so it is important to give them a break and rotate livestock regularly. And, of course, you can rotate between crop fields and pastures for livestock to add valuable manure to the soil. “Pasture and forage crops in rotation enhance soil quality and reduce erosion; livestock manure, in turn, contributes to soil fertility,” according to the University of California, Davis. “Livestock can buffer the negative impacts of low rainfall periods by consuming crop residue that in ‘plant only’ systems would have been considered crop failures.” Meanwhile new technologies such as those used in precision farming can help to limit runoff when applying fertilizers and herbicides, while saving farmers money at the same time. Fertilisers and herbicides are expensive, so using less also makes financial sense.



Machinery with remote sensing, detection, monitoring and decision support systems allow growers to inject fertilizers exactly where they are needed. The machines can distinguish between green and brown, for example, and are thereby able to target applications precisely. Geomapping helps determine nutrient levels and soil health, which again can be fed to the machinery to adjust what is added to a particular area. So there are plenty of technological advances that support a transition to more sustainable practices.


Organic Fertilisers


And then, you can always make up your own organic fertilizers instead of paying for chemical ones. One farmer in Australia’s state of Queensland started looking for new solutions when he took over the family farm and realised that productivity had declined over the years. "The soil had been depleted over decades and decades of farming but I knew adding more synthetic fertilisers wasn't going to fix the problem," Ray Zamora told the Australian Canegrowers Magazine, adding he undertook training to improve the health of his farm. "I decided to do this course on brewing up your own bio-fertilisers,” he told the magazine. “It’s just like home-brew beer, it’s a fermentation process, it bubbles away, then in a month to six weeks you have a batch ready to go.” Since starting to use his homemade bio-fertiliser, Mr Zamora has harvested some of his biggest crops, while still cutting back on nitrogen input. In addition, he is improving soil health by rotating between grasses, legumes, cereal crops and chenopods, he told Canegrowers. “The more mixes (of cover crops) you’ve got the more diversity there is in the soil and the better the outcome for soil health and crop production,” Mr Zamora told the magazine. To add more diversity of plants, reintroducing hedgerows can also improve soil health. 


Financial incentives


The University of California, Davis, runs research into making the establishment of hedgerows more attractive to farmers – by adding financial incentives. The university’s Agricultural Sustainability Institute has focused on elderberry hedges, in particular. “Elderberries are typically grown on farms as hedgerows for their ability to attract beneficial insects, act as a windbreak, and sequester carbon, benefiting the overall health of the farm, but not providing direct benefit to a farmer's bottom line,” the institute wrote in a blog post. Together with a nearby farm, the university is therefore investigating various uses for elderberries, such as in syrups, jams, wine and liqueur, to identify ways that hedges could add to growers’ income. “Elderberry juice is already in so many products, so building a market for locally grown elderberries seems like a no-lose situation,” one of the participating farmers, Katie Fyhrie, told the university. Making agriculture more sustainable as well as getting some delicious jams and wines sounds pretty good, don’t you think?


And if we all care more about the origins of our food, and vote with our wallets by buying sustainably produced goods, every individual can make a difference.

Sustainable Development

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