December 2020
Volume 4, Issue 3

Sustainable Agriculture

Agriculture lies deep in the roots of our country and university’s history. While it has evolved over time, it continues to change. Today, agriculture has begun to take a more sustainable form to not only increase efficiency, but also better manage our natural resources.

Image: Apple orchard via pixabay

Image: Apple orchard via pixabay

Statistics on Agriculture

            The earth’s surface is 149 million km² of land, 51 million km² (~34%) is used for agriculture use around the world. Of the land set aside for agricultural purposes, 77% of that is used for livestock and 23% is used for growing crops.[1] In the United States alone, the total area of land is 9.8 million km², and around 52% is used for agricultural purposes.[2] Between 80-90% of water consumption in the agricultural industry is used for irrigation in order to adequately water crops. With the threat of climate change increasing the length of drought seasons, the need for water will only increase.

Sustainable Agriculture

            There are several different types of agricultural practices that work to create sustainable systems that tie in the foundational pillars of sustainability. Ranging from utilizing fish to purchasing local, below are outlined several practices that highlight some of the growing areas of sustainable agriculture.

[1] https://ourworldindata.org/global-land-for-agriculture

[2] https://www.ers.usda.gov/topics/farm-economy/land-use-land-value-tenure/major-land-uses/

Permaculture

A term created by Bill Mallison and David Holmgren in Australia during the 1970s combined the words “permanent agricultural” but later expanded to “permanent culture,” permaculture is a closed-loop system that integrates land, resources, people, and the environment to appear similar to a natural ecosystem.[1] This system includes many branches such as ecological design, energy, sustainable architecture, waste management, and forestry. Holmgren’s book Permaculture: Principles and Pathways Beyond Sustainability listed 12 principles of permaculture, including the key principles of producing no waste, applying self-regulation and feedback, use and value renewables, and creatively use and respond to change.[2] There are currently 2,667 permaculture projects happening around the globe that you can explore on the Permaculture Global webpage.

 Regenerative Agriculture

Regenerative agriculture describes farming and grazing practices that reverse climate change by rebuilding soil organic matter and restoring soil biodiversity. These practices allow carbon drawdown and an improvement in the water cycle. It is a holistic land management practice which uses the power of plant photosynthesis to close the carbon cycle, and build soil health, crop resilience, and nutrient density. This type of agriculture’s practices include no or minimum tillage, increasing soil fertility, building biological ecosystem diversity, and well-managed grazing practices. Minimal tillage prevents the pulverization of soil aggregates and fungal communities. Tillage does just that, while also adding excess O2 to the soil and increases the respiration and CO2 emission. Along with other regenerative agricultural practices, little to no tillage can enhance soil aggregation, water infiltration and retention, and carbon sequestration. Improving soil fertility is also another important regenerative agriculture practice. This can be done biologically through cover crops, crop rotation, and composting.

Another regenerative agriculture practice is building biological ecosystem diversity. This can be achieved through inoculating soil with compost to restore soil microbes, structure, and functionality. This, in turn, restores the energy of the soil system through full-time planting of many intercrop plantings, multispecies cover crops, and borders planted for beneficial insects. Lastly, regenerative agriculture involves well-managed grazing practices that stimulate improved plant growth, increase soil carbon deposits, and pasture and grazing land productivity. This happens all while increasing soil fertility, biodiversity, and soil carbon sequestration. Using these practices improve ecological health and the health of humans and animals through improved micro-nutrient availability and better dietary omega balances.[3]

Composting

Composting is the natural process of recycling organic material, such as leaves and food scraps, into a rich soil amendment. This rich soil amendment is known as compost, which is decomposed organic matter.[4] There are many different types of composting techniques, which include hot composting and vermicomposting. One of the most popular backyard composting techniques is hot composting. Hot composting, also known as open air composting, is traditionally just a pile of brown and green matter commonly done in backyards. These brown and green materials are then typically layered upon each other, and turned every so often to aerate the soil and assist with decomposition. Vermicomposting, also known as worm farm composting, is where worms are added to compost piles and they produce casting concentrated with nutrients that are low in nitrogen.[5]

Crop Rotation & Diversity

Crop rotation is the repetitive growing of an ordered succession of crops on the same land over multiple years.[6] Crop rotations are a fundamental part of organic systems. For example, crops like legumes, which are rich in nitrogen, are often planted to enhance nutrient cycling and availability to other crops within the rotation. These crop rotations can also be diverse. Diversifying crop rotations also improve crop yield. This has been seen in research which was conducted in a long-term crop rotation trial in central Pennsylvania. There are also many other reasons why crop rotation and diversity are very beneficial. Crop rotation is also an important tool used for pest management. Certain pests target specific crop species, but when they are rotated the target crop is no longer present. Weeds can also be controlled through diverse crop rotation because they can be controlled through a range of practices. Crop diversity can also help improve soil health. By diversifying crops above ground, a diverse microbial community below ground. Rotating crops can also allow machinery to be used more efficiently year-round instead of just for specific crops at certain times of the year.[7]

[1] https://www.permaculturenews.org/what-is-permaculture/

[2] https://ethical.net/ethical/permaculture-principles/

[3] https://regenerationinternational.org/2017/02/24/what-is-regenerative-agriculture/

[4] https://www.epa.gov/recycle/composting-home

[5] https://www.directcompostsolutions.com/8-methods-composting/

[6] https://www.nrcs.usda.gov/wps/portal/nrcs/detail/pa/soils/health/?cid=nrcseprd1187608

[7] https://www.nrcs.usda.gov/wps/portal/nrcs/detail/pa/soils/health/?cid=nrcseprd1187608

Hydroponics

Hydroponics is the cultivation of plants without the use of soil. Plants are inserted into an inert growing media (or growing media that has no nutrients), and the roots are submerged in nutrient-rich and oxygenated water.[1] There are six types of hydroponic systems: deep water culture, wick, nutrient film technique, ebb and flow, drip, and aeroponics. The only difference between these systems is the way water is delivered to the roots of the plant. The versatility of the design of these systems allows them to be used in small spaces. There are hydroponic systems that are on top of each other or are hanging from the ceiling. Thus allowing them to be popular in cities and even used in space programs.[2] The most popular plant when using hydroponics is leafy greens such as lettuce. Most plants can be used with this system but bush, vining, or large rooted vegetables are often not planted due to space needed for them to grow.[3]

This type of cultivation is expensive when starting to build the system but has been proven to be more effective than plants grown in soil. Nutrients and water can reach the roots more efficiently, thus allowing more energy for the plants to put towards growth. There is also the advantage for farmers to be allowed to have more control over environmental conditions and less exposure to pests or fungus when planted in soil.

Image: Example of a hydroponic set-up via pixabay

Image: Example of a hydroponic set-up via pixabay

Aquaponics

Another form of hydroponics is aquaponics. Instead of people adding nutrients to the water solution, fish waste is used. This form of cultivation uses the main idea of permaculture, “produce no waste” and mimics natural ecosystems. Fish tanks and hydroponic beds are connected in a closed loop. Farmers feed the fish, which eat the feed and then process it into waste. The waste excreted is rich in ammonia which passes through a biofilter where bacteria break down the ammonia and other waste into beneficial nitrogen that then passes to the plants. Finally, the plants absorb the nitrogen to grow and purify the water that is then returned to the fish tank. This system can also be adjusted to fit on top of a countertop or used in large-scale farms. The main issue with aquaponics compared to hydroponic systems is that bacteria is a very important factor for the system to work. Nitrosomonas and Nitrobacter are important for the process of nitrification, the process of converting ammonia to nitrates.[4] This process is important because small amounts of ammonia can kill the fish and plants.

 Cover crops

Cover crops are crops that are grown primarily for the benefit of the soil rather than yield.[5] They can be used to suppress weeds, prevent soil erosion, improve soil fertility and quality, control pests and disease, promote biodiversity, and improve soil nutrients. As you can see, these crops have the potential to provide many benefits to crop systems. The type of crop that is used is typically dependent upon the desired benefits.[6]

[1] https://www.freshwatersystems.com/blogs/blog/what-are-hydroponic-systems

[2] http://sitn.hms.harvard.edu/flash/2019/hydroponics-the-power-of-water-to-grow-food/#:~:text=Aerospace%20plant%20physiologists%20at%20NASA,grown%20leafy%20vegetables%20in%202015.

[3] https://rurallivingtoday.com/hydroponics/what-cannot-be-grown-hydroponically/

[4] https://blog.stuppy.com/aquaponics/the-stuppy-aquaponics-curriculum-part-5-types-of-bacteria-in-aquaponics#:~:text=In%20aquaponics%2C%20two%20genera%20of,an%20aquaponics%20system%20in%20balance.&text=converts%20ammonia%20to%20nitrites%20and,converts%20nitrites%20to%20nitrates.

[5] https://www.thespruce.com/definition-of-cover-crop-3016953

[6] https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/climatechange/?cid=stelprdb1077238#Cover%20Crop%20Plant%20Guides

Farmers Markets & Community Gardens

Image: An example of a farmers’ market via pixabay

Image: An example of a farmers’ market via pixabay

Farmers markets and community gardens are great ways to get people involved in sustainable agriculture. Farmers markets are great ways to shop locally and support local farmers. Many of the farmers engage in sustainable agricultural practices in order to produce healthy food to sustain the local community, which helps sustain the farms. Many of these farms also practice natural or organic farming, which are in increasing demand.[1] Community gardens allow people to be a part of the growing process and can help reduce negative environmental impacts by promoting sustainable agriculture. These gardens can also reduce food transportation costs, help reduce water runoff, and address issues of food insecurity within communities. They can also serve as green spaces in communities which is beneficial for the mental and emotional health of community members, in addition to reducing the urban heat effect.[2]

Looking to learn more or get involved in sustainable agricultural practices? We have some amazing organizations right here on campus!

[1] https://farmersmarketcoalition.org/education/farmers-markets-promote-sustainability/#:~:text=Farmers%20engage%20in%20sustainable%20farming,necessary%20to%20sustain%20the%20farmers.&text=Each%20year%2C%20more%20and%20more,for%20natural%20and%20organic%20food.

[2] https://greenleafcommunities.org/the-many-benefits-of-community-gardens/#:~:text=Community%20gardens%20can%20help%20reduce,the%20ecology%20of%20the%20area.

Stay in Contact with Residence Life Sustainability

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Texas Urban Farms United (TUFU)

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