What to Do With Crop Residue?
Farming is a lot of work. Seeds need to be planted, the growing crops need to be tended to, and finally the harvest occurs at the end of the growing season. After the harvest, the field is considered to be in no shape for the next season’s seedlings. Often, the field is riddled with crop residue, which is the leftover growing material such as stalks and husks. When it comes to removing these remains prior to reseeding, farmers have a few options. Tilling is the common practice of plowing the dirt surface and residue under the ground and this turning of the soil allows fresh dirt to rise to the top. It is not an eco-friendly process because it degrades the integrity of the soil and makes it more susceptible to wearing down. An alternative is burning off the residue but this also is not sustainable and arguably worse than tilling. Burning increases the soil’s PH and diminishes its organic matter. The heat wipes out bacteria and the burning results in air pollution including carbon dioxide emissions. This practice is also harmful to wildlife. On Rachel Greiman’s blog ‘Green Chair Stories’, she recants taking a tip to Belize and the opportunity to witness farmers burning their field. Afterwards, while surveying the aftermath, she found dead snakes throughout the charred field. It is easy to understand why farmers choose to burn. There isn’t a quicker and easier way to clean out a field than by setting it ablaze. For most farmers, though, it is likely in their best interest to find an alternative method due to the toll burning takes on their soil.
Mexico is one country that intensively employs crop burning and also suffers from poor air quality – air pollution in Mexico City reached six times the acceptable limit earlier this year. It is not uncommon for the smoke to blow up from Mexico to Texas during the spring burning season. The International Maize and Wheat Improvement Center (CIMMYT), a Mexican not-for-profit organization, recognizes the issue and is working to educate farmers about the importance of adopting sustainable methods. A few years ago, it initiated the Sustentable Yucatan Peninsula (English translation: Sustainable Yucatan Peninsula) project to assist the peninsula’s farmers with finding the best soil to cultivate, and teach them how to manage this soil efficiently and viably. Many peninsular farmers have carried on the ancient Mayan intercropping system called “milpa”, and the project helps them improve upon their traditional method.
The time-honored milpa process is a form of slash-and-burn agriculture; a plot of forest is cleared, allowed to dry, and then burned to finish clearing the area. Next, seedlings for a variety of different crops are interspersed throughout the newly formed field. Corn, beans, and squash are some of the field’s fastest yielding crops, although the milpa farmers simultaneously allow trees to take root in the growing area. The developing trees eventually create shade, which is especially beneficial for some crops such as palms. A portion of the trees bear fruit. Ultimately, as the trees continue to mature, the former field becomes reclaimed by the forest. The woodlands remain in-place until they are cleared so that the milpa cycle can continue again. There are a couple reasons why traditional milpa is not considered sustainable today. First, as explained earlier, there are the negative consequences of burning the land. Also, the customary Mayan practice was to allow the land to grow for about 30 years before being cleared again. Today, land is recleared about every 16 years resulting in the issue of the soil health having less time to regenerate.
Through Sustentable Yucatan Peninsula, farmers are taught an innovative farming method that includes elements of traditional milpa but incorporates new techniques that make the process sustainable. Crop diversification still plays an important role, either through intercropping or crop rotation. Farmers are also learning how to farm their land while disturbing the soil to the least extent possible, and are greatly reducing the use of tilling. By taking care of their soil, there is no need to abandon their fields and cut down more forest. Farmers are also being trained to not remove crop residue. This results in continual soil cover, reduced water runoff, and less evaporation. This strategy benefits the environment because there is no need to burn off residue. So far, the project’s results have been promising. Farmers who adopt the project’s methods are reporting better yields, especially for corn. For example, Francisco Canul Poot has experienced a 70% gain in corn harvested per hectare on his farm on the peninsula.
CIMMYT has received funding for Sustentable Yucatan Peninsula and other sustainable corn and wheat agriculture projects from Mexican not-for-profit Fundación Haciendas del Mundo Maya, which in turn is supported by the Haciendas Luxury Collection Hotels. The hotel company operates five luxury hotels on the Yucatan Peninsula. Each hotel makes use of a historic building. For example, Hacienda San Jose had a former life as a 19th century sisal plantation prior to falling into disrepair and then later being saved and transformed into the hotel. Hacienda San Jose is situated in the middle of the jungle, which makes for a unique experience for many of the guests. On her blog ‘A Tiny Trip’, Daphna writes, “The property of Hacienda San Jose was magical. We spent our time there just exploring the little pathways all around, observing the gorgeous landscaping, and enjoying a true luxury experience.” Part of what completes the experience are the array of flowers that colorfully decorate the walkways during the day, and the many flickering candles that dot these paths and make them so captivating at night. In addition to providing guests with an ultimate vacation stay, the company has been taking steps to make their premises eco-friendly. One way Hacienda San Jose makes an impact is by using high-efficiency lighting in its guest rooms to cut down on its energy usage.
Mexico’s Yucatan Peninsula still faces challenges but the work being done by organizations such as CIMMYT, with help from supporters like the Haciendas Luxury Collection, is helping to make the region more sustainable. Hopefully more regions will take note of the peninsula’s farming success and reconsider how to handle their crop residue.
Sugar…And fires and smoke and snakes, oh my – greenchairstories.com
Sustainable agriculture for healthy forests – cimmyt.org
Effects of Slash-and-Burn-Farming and a Fire-Free Management on a Cambisol in a Traditional Maya Farming System – redalyc.org
Helping farming families thrive while fighting climate change in Mexico – cimmyt.org
What is conservation agriculture? – cimmyt.org
Sustainable tradition – cimmyt.org
Milpa Cycle Notes – belizehistorysjc.org
Mexico City air pollution spikes to 6 times acceptable limit – apnews.com
Smoke from agricultural fires in Mexico decreases this weekend – kvue.com
A knowledge revolution – cimmyt.org
Hacienda San Jose Resort Overview – marriott.com
Featured crop residue photo by USDA NRCS on Wikimedia Commons
Secondary photo of crop residue by USDA NRCS on Wikimedia Commons
Photo of milpa farming by Ll1324 on Wikimedia Commons
2 thoughts on “What to Do With Crop Residue?”
What do the farmers in New York and other states do with crop residue? Till it under? Do they use any other methods?
Tillage remains to be the most common method in the U.S., although this practice has been on the decline over the past decade. Farmers have been adopting no-till methods and not removing the crop residue, which is easier to accomplish with today’s technology such as no-till drills. No-till farms are most common in the heartland states. New York and various other states have a portion of farms that practice reduced tillage – some crop residue is left in place to limit the need for tilling. While not so common, crop burning does exist in the Southeast, Great Plains, and Northwest.