Guest Post by Anna Freiji
Big ag. Small ag. Organic, Farmers’ Markets , and *gasp* GMOs! There is a lot of talk these days about how our food is produced and why you should (read: only if you love your children) choose one type of produce over another. There are many reasons to choose to promote one type of agriculture or another through your purchases: a closer (or more distant) connection to your food, health, the environment, or just pure convenience. But in this post I want to discuss not what you should be eating or the differences between organic and conventional agriculture, but give you an overview of some of the issues that farmers face within the realm while trying to farm sustainably.
To start, let’s take a look at what good ol’ Merriam-Webster has to say:
Sustainable (in reference to sustainable agriculture): “of, relating to, or being a method of harvesting or using a resource so that the resource is not depleted or permanently damaged” 1
Basically, sustainable agriculture is a means of producing food (and I’m talking primarily about plant-based food in this article) that could go on forever without significant negative environmental consequences. At best, sustainable agriculture can actually leave the environment healthier than it originally was.
Growing food is all about making sure the plants have the right nutrients, water, and a good amount of sunlight. This means that we need to maintain healthy, nutrient rich soil (or the correct nutrient balance if being grown hydroponically) and give the plants enough space to get the light they need so they can photosynthesize away and produce sweet, wonderful produce. After that, it’s making sure that other organisms don’t eat the plant before we do. It sounds simple…until you realize how many other organisms you are going to have to fight against to protect the growing plants, and until you consider that nutrients are like food. Once a plant consumes them, they are gone, leaving only what they didn’t use themselves for whatever plants are sown the following year. The question then is how do we overcome these hurdles. And here is where we start to wade into more controversial waters. There are trade-offs to every decision, and before we villainize anyone who reaches for the spray bottle of chemicals, please first try to consider the complexity of the issues.
How do farmers deal with pest issues (weeds and plant pathogens)?
If the first thing that comes to mind when you read this question is “spray!” then you are not alone. Spraying a pesticide of some sort is a common practice to kill nuisance pests like weeds or fungi. However, if you think that “big ag” farms reach for the sprayer every time they see a fungal spot or a fly in their field, you would be wrong. Spraying pesticides is not cheap, so if they can avoid having to spray for a disease by using other cheaper means, all the better!
Several other management practices utilized to help prevent and/or manage diseases include planting seed that has resistance or reduced susceptibility to a given disease, crop rotation, protecting them from unnecessary mechanical damage, and helping the plant avoid stress by providing sufficient nutrients and water.
Speaking of alternative pest control options, let’s take a second to discuss GMOs. GMO stands for Genetically Modified Organism. These are organisms with foreign DNA (DNA from a different species) inserted into them to give them a novel trait. A commonly used GMO organism in the U.S. is what’s called Bt-corn. Bt stands for Bacillus thuringiensis, the name of the bacteria that “donated” the gene to make Bt-corn. The gene from B. thuringiensis allows the corn to produce a compound that is poisonous to the European corn borer and southwestern corn borer larva, while minimally (if at all) poisonous to organisms outside of the Lepidoptera order (butterflies and moths). This means that the Bt gene is not going to produce anything that will be poisonous to bees, fish, or mammals (including us!). By using Bt corn, farmers don’t have to worry about spraying insecticides to manage either of these pests, which is good news environmentally.
However, there are also GMOs, like Roundup® ready soybeans, that promote the use of a pesticide instead of deterring it. Roundup® ready soybeans are genetically modified so that they are not killed when sprayed with glyphosate (trade-name: Roundup®). This promotes the use of glyphosate as a weed killer in fields planted with this type of soybean. Before we all pronounce judgment on GMOs of this sort, though, please take a moment to picture 100 acres. Now imagine that it is your job to go out and hand-weed this 100 acres. By the time you finished weeding, the weeds near the front of the field would likely already be high enough to make you want to throw in the towel then and there.
Also consider the following question: What is our concern with pesticides as they relate to sustainable agriculture? The big concern is that non-target species will be harmed, either in the soil or in the water if it leaches out of the soil. However, not all pesticides behave the same. Some may be able to biodegrade in the soil relatively quickly (though into what is a fair question to ask) or they may not have a tendency to leach into surrounding areas making them less of a hazard to fish and other aquatic species. Some may have long lasting impacts on the environment once applied or be highly toxic to fish and other wildlife. This is not an area I have great expertise in, so I encourage you to look up any given pesticide that you have concern with on a reputable government or academic website and see what threat it may pose. Keep in mind though that even water can pose a risk to human health (…drowning).
How do we feed our crops?
Crop nutrition is a huge issue when it comes to sustainable agriculture. The Biblical idea of sowing what you reap is directly applicable to agriculture as you can’t expect to keep farming the same land over and over without sowing any additional nutrients and expect the soil to remain fertile. But an overabundance of nutrients can be a waste if they leach out into the surrounding water ways, feeding algae that then overgrow, die, and decompose, depleting the oxygen in the water and creating dead-zones.
So when runoff causes horrible things to happen to the environment, what is a farmer to do? A good thing to do is to apply only the nutrients that are needed, at a rate that will be taken up and used by the plants. In human terms, this means that you don’t just feed your kids one huge meal and then let the rest go to waste, wanting to make sure they have enough food. You feed them when they are hungry, and give them a reasonable portion (or something to snack on throughout the day, as would be more or less the case with slow-release fertilizers). And if one child is less hungry than another, you give them a smaller portion. The same applies to agriculture. Farmers looking out for their bottom line don’t want to be wasting time or money applying fertilizers that are just going to wash away, not contributing to a higher yield. So farmers rely on agronomic research to tell them the correct rate at which to apply given fertilizers based on the nutrients already available in their soil. Something very exciting on this front is that precision agriculture is making it possible for farmers to differentially apply fertilizers based on the results of soil tests from their fields. This means less money going to waste while maintaining good plant nutrition, and, if applied at the correct rate, hopefully less nutrient runoff into surrounding water ways.
Organic fertilizers such as compost (organic if made with organic ingredients), manure, or bone meal can be used in place of chemical fertilizers, and I believe that you can’t get much better fertilizer than rich, sweet smelling compost. Compost provides nutrients to the plants and feeds the soil, helping to build the soil over time. In addition, in adding manure or compost, you will likely be adding beneficial microbes, helping to build a healthy soil, which will in turn help produce healthy plants. When adding fertilizer of any kind, care needs to be taken to ensure the safety of those applying it, and the safety of future consumers.
We can’t discuss sustainable agriculture without discussing the issue of water. Plants need water to grow, but what do you do in a desert area or one that doesn’t provide enough rainfall naturally to sustain a crop? Well, some say irrigate. I say, if the land can’t sustain it, stop trying to force it. The water has to come from somewhere, and if we continue to use up aquifer water or river water in amounts that aren’t being replenished by the rains, then the practice cannot be called sustainable agriculture.
This isn’t to say that if you live in a dry area you can’t grow food. I currently live in Kenya, where we think about the rains a lot. We actually filter water from a large rain tank as our normal drinking water. Rain tanks are an amazing way to store water when it comes in abundance (collecting it from the roof of a building where it won’t be utilized by the crops anyways) and use it later for irrigation. Practicing no-till farming that leaves crop residues on the soil surface can also help since it reduces the amount of water that will be lost through evaporation. Additionally, healthy, permeable soil can help with the issue of water conservation as it will be better able to hold onto the water the land does receive…which brings us to our last major topic – soil.
When it comes down to it, I believe that so much of sustainable agriculture hinges on how farmers think about and treat the soil they farm. If we don’t feed and care for the soil, how can we expect to reap abundantly from it? Life brings forth life. It’s the way God created it. So to me, sustainable agriculture finds ways to protect and build up the soil. How is this done? Well, here are two common practices that are promoted for soil conservation (though this is not all that can be done to help preserve and build up the soil…see my earlier comment on using compost).
- Cover crops – cover crops are a big topic these days due in large part to the role they can play in soil conservation. Having plants in the ground during “off-seasons” (in the U.S. this typically means winter or post harvest), protects the soil as the roots hold onto the top soil and the plants provide a wind break, sheltering the soil from being blown away. Cover crops also protect the soil from heavy rains as the leaves slow down the speed of rain drops, protecting the soil from being displaced by the water in large quantities. This means that less of the rich top-soil will end up being wasted, flowing into a nearby river or lake. Additionally, some cover crops (leguminous crops – bean or pea plants) are able to fix nitrogen, converting nitrogen present in the air into a form that the plants can use. They can also help suppress the growth of weeds.
- No-till – soil does best when it remains intact, and tilling disrupts this. When the soil is turned up, it disrupts its structure and it can lead to increased erosion. Additionally, if plant residue is plowed into the ground, the uncovered soil will be exposed to the sun, increasing water evaporation rates. Tilling can also cause a crust to be formed in or on the soil, which reduces the soils ability to absorb water. A disrupted soil structure also reduce the soils water holding capacity.
There are a lot of factors for farmers and consumers alike to consider when thinking about sustainable agriculture, just like there are many factors for each of us to consider when trying to live more sustainable lives. Though I do believe that there are ways to farm that are very unsustainable, I also don’t think that the “right” answer is always as obvious as we may like to think. There are ideals, and then there is the fact that we live in a fallen world where plant pathogens still attack our zucchinis, and slugs eat our strawberries. But before I sign off, I want to give you some questions to ask when trying to determine if produce is being farmed sustainably.
- What is your attitude toward the soil you farm on?
- Do you use cover crops?
- Do you practice no-till?
- What nutrient inputs do you use? (if they compost, that’s a really good sign)
- Do you/ how do you irrigate your crops?
- Do you practice crop rotations?
- Are you raising plants that can be raised with a sustainable amount of water (aka: raising drought tolerant plants in the desert, not trying to grow water-needy plants in a dry area).
- Are there any other conservation practices you have on your farm?
And if a farmer says that they don’t do X, ask why. Farmers have to think about their bottom-line too, but in asking a farmer about these issues, you may become more aware of the problems they face. Who knows, you may even run into an problem you want to help solve!
So as we consider how to grow food sustainably, let us look to our natural surroundings for guidance, caring for the land as stewards of it. Let us learn about the land, because we cannot love well what we do not know well. And if we do not know it well, how will we care for it well?
My name is Anna Freije, and I am currently serving as a missionary in Kenya. I have a master’s degree in plant pathology (plant diseases) and a love for God, the environment, and food (from growing it, to cooking it, to eating it). I’m currently learning a lot about gardening as I work to help install sustainable gardening practices in a garden here in Kenya. (caveat: I am by no means an expert in all things sustainable agriculture, so I encourage you to dig deeper into any of the topics below that interest you.)
Sources/ resources, and a few TedX talks worth watching: