Several LSU AgCenter scientists discussed their work on row crop management practices at the 20th annual National Conservation Systems Cotton and Rice Conference.
The event, held Jan. 30 to Feb. 1 at the Crowne Plaza hotel in Baton Rouge, featured presentations by 113 speakers, including farmers, crop consultants, university researchers and extension specialists.
AgCenter soybean specialist Ronnie Levy talked about the advantages and drawbacks of conservation tillage, a system in which farmers till soil minimally, if at all, and leave residue from harvest in fields.
The residue reduces erosion by slowing water and wind movement across the soil surface, he said. It also holds water and reflects heat, minimizing the large temperature variations between day and night that are common in spring.
The organic matter sometimes keeps the soil too cool, however, and delays early soybean planting, Levy said. Many Louisiana farmers plant soybeans in March and April so plants can complete critical growth stages before intense summer heat arrives.
Average Louisiana soybean yields have increased 15 to 20 bushels per acre in the past few years, and “a lot of it can be attributed to early planting,” Levy said. Late-season planting in May and June remain common but yield 20 to 25 fewer bushels per acre than early soybeans, he said.
AgCenter economist Naveen Adusumilli encouraged farmers to find ways to implement practices and use technologies that help them lower costs and irrigate more efficiently. The AgCenter is preparing to release an app to help farmers calculate cost savings for irrigation upgrades.
Blake McCartney, who farms in northwest Louisiana and has been working with Adusumilli, said he has improved irrigation efficiency with surge valves, which swap water flow from side to side, and Pipe Planner software that helps farmers determine the number and size of holes to punch in irrigation poly pipe.
AgCenter plant pathologist Trey Price said managing canopy growth in cotton plants is key to controlling a number of diseases, including two major concerns this past summer: boll rot and target spot. Both diseases thrive in humid conditions.
Target spot quickly defoliates plants and can result in yield losses if the disease appears early in the season. Price said farmers should check for target spot lesions while plants are young and, if necessary, apply fungicides before the canopy closes.
No fungicides are available for controlling boll rot.
AgCenter plant pathologist Clayton Hollier told about a new project to gather data about how defoliation of corn plants – which can be a result of pathogens, insects and environmental factors – affects yields. Early-season defoliation of lower leaves appears to cause the greatest yield reduction, he said.
Hollier hopes the data will provide insight as to when fungicides should be applied to best protect yields.
“We’re starting to see the impact of these leaves and what they contribute toward yield,” he said.
AgCenter corn specialist Dan Fromme said farmers may be able to reduce the amount of nitrogen fertilizer they apply and still maintain good corn yields. Many farmers are trying to cut input costs because of poor corn prices in recent years, he said.
In trials this past season in central Louisiana, Fromme found that plots treated with 150 to 175 pounds of nitrogen per acre had yields comparable to applications of 200 to 225 pounds of nitrogen per acre.
The amount of nitrogen needed varies from year to year and depends on soil type, irrigation and other factors, Fromme said.