Field Day In Erath Focuses On Climate-Smart Agriculture
GABRIELLE BELLELO
ERATH, LOUISIANA
An LSU AgCenter field day held at a commercial sugarcane farm in Erath focused on climate-smart agriculture solutions that any farmer can implement.
Attendees were transported from the venue location to the field in air-conditioned, yellow school buses – a welcome getaway from the summer heat.
Brenda Tubaña, AgCenter soil fertility expert and lead scientist of the Best Management Practices on Model Farms project, opened with a question at the first field stop.
“What is the allocated amount that we are investing when it comes to fertilizers or soil amendments?” she asked.
Tubaña explained that soil fertility accounts for about 22% of sugarcane productivity and that it involves far more than nutrient availability alone.
“It’s about the workability of the soil, the good physical properties that allow low resistance for roots to penetrate the soil profile and the good moisture-holding capacity of the soil,” Tubaña said.
Despite fertilizer representing around 30% of total production costs, not all applied nutrients are efficiently used by crops. Therefore, it is important to make sure soil retains its ability to supply nutrients to the main crop by sustaining organic matter content, moisture availability and microbial activity.
“Cover cropping increases organic matter and improves soil structure, which helps control erosion and reduce runoff,” she said. “Water conservation and water quality are also enhanced, and we can reduce fertilizer input by using cover crops.”
While the effects of cover cropping are not immediate, the long-term benefits from consistent implementation can lead to significant reductions in fertilizer usage, especially nitrogen and potassium.
“The biomass from cover crops releases nutrients back into the soil, allowing us to apply less fertilizer over time,” Tubaña explained. “It’s a system that builds on itself through sustained management.”
Cover crops also promote biodiversity, which creates a more resilient and sustainable farming system.
At the second field stop, AgCenter agent Blair Hebert introduced the next topic.
“Being a cane farmer, or any kind of farmer, is not an easy task,” he said. “At the first stop, we covered the importance of what we can do in the fallow period before planting. Now, we will talk about what we can do after harvest.”
Jim Wang, AgCenter soil scientist and principal investigator of a Natural Resources Conservation Service-funded project on climate-smart agriculture solutions, talked about the harmful greenhouse gases that can be created from traditional agricultural practices.
“Nitrous oxide is significantly more potent than carbon dioxide, equivalent to 273 times of CO2,” Wang said. “It is created by the nitrification-denitrification process after applying nitrogen fertilizer. While CO₂ accounts for about 80% of total greenhouse gas emissions, nitrous oxide represents 6%. However, 70% of that comes from soil emissions due to nitrogen fertilizers used in agriculture.”
Wang’s research aims to quantify emissions from sugarcane production, comparing the effects of both traditional and climate-smart practices like cover crops and nitrogen stabilizers.
“Our goal is to get farmers to participate in voluntary carbon markets to earn carbon credits. That’s the future we are shooting for,” Wang said.
Errol Domingues, of Domingues Farms, addressed billet planting and the occasional need for field burning.
“No one wants to burn, but sometimes it’s a necessity,” he said. “Our goal is to maintain our farm-friendly presence in the community and to show the public we’re good stewards of the land by finding ways to avoid burning where we can.”
Tubaña returned to talk about how researchers manage nutrients in demonstration trials at Domingues Farms.
First, they attempt to increase the use efficiency of fertilizer input – mainly nitrogen because it is often the most limiting nutrient in every cropping system, including sugarcane. Then, they aim to reduce the amount of nitrogen applied through the adoption of various integrated practices.
Among those practices is the use of nitrogen stabilizers, which slows nitrogen transformations and reduces nitrogen losses via leaching and runoff.
“When stabilizers are used, we see more efficient utilization,” Tubaña said. “More of the nitrogen per unit applied is converted into tonnage and sugar yield.”
Another tool featured was variable rate technology (VRT), which allows precision nitrogen application of fertilizer across fields.
“These sensors are nondestructive and noninvasive,” she said. “That means you don’t have to cut cane samples to monitor the nitrogen status of your crop.”
Tubaña also demonstrated the use of nitrogen-rich strips, which serve as a visual guide to roughly estimate nutrient needs. These are placed in the field three weeks prior to fertilization and compared to the untreated areas to determine if additional nitrogen is needed.
“Those are the things that we do to help cut down the amount of greenhouse gases that we release to the atmosphere and reduce nutrients that are lost from the field,” Tubaña said.
The team of researchers plans to continue collecting data on greenhouse gases emissions, nitrogen turnover rate and organic matter content in the soil.
The AgCenter’s Best Management Practices on Model Farms project is funded by a grant from the Patrick F. Taylor Foundation. For more information, visit www.LSUAgCenter.com/taylorgrant. ∆
GABRIELLE BELLELO
LSU AG CENTER