Using Durana Clover as a Living Mulch in an Integrated Corn and Livestock Production System

Using Durana Clover as a Living Mulch in an Integrated Corn and Livestock Production System

Summary

A comparison of row spacing, spray band pattern, and population density was compared using sweet and field corn grown in the living mulch system. Population density reduced field corn yield but other treatment variables did not. Optimum sweet corn production was with wide row spacing, band spray, within the low population density treatments. Clover re-establishment was greatest in narrow herbicide band treatments. H-flumes have been instrumented in water sheds to measure runoff, nutrient losses and fall management of clover after field corn harvest. Interest in the project has been broad, including producers, other researchers, food industry groups, and politicians.

Objectives/Performance Targets

Objective 1: Identify the best row spacing, population density, and clover suppression combination for field and sweet corn production. Objective 2. Optimizing fall clover re-establishment within corn row spacing, strip-till band width, and population density variables. Objective 3. Obtain an approximation of how much N is transferred fromwhite clover to corn in a living mulch system. Objective 4. Determine the impact of the living mulch corn production system on water runoff and quality.

Accomplishments/Milestones

A factorial of two row spacings (30 and 36 inch), two herbicide banding widths (8 and 16 inches), and two population densities (24 and 36K plants/A) were established in the living mulch system. Sweet corn was established in one location while field corn was established at two research locations. The clover stand planted to both field and sweet corn was was in its first year but the clover at the second field corn experiment was in its second year of establishment. Clover biomass, corn height, and shading were monitored from pre-planting until tasseling. Clover was the sole source of N for the field corn grown in the 2 year old stand but other locations received 50 lb/A N (field corn) or 100 lb/A N (sweet corn). Corn was hand harvested in July (sweet corn) or early September (field corn). Sweet corn produced the most ears at the highest population density, but the best quality sweet corn (length and width of cob) occurred at lower population density, wide herbicide band width, and wide row spacing. Field corn had greatest yields at high population density but was unaffected by row spacing or herbicide treatment. High population density grain yields were 195 and 242 bu/A for the one and two year old clover stands, respectively. Clover basal cover was measured after harvest. Narrow herbicide applications resulted in complete recovery to a solid clover stand approximately 84 days after harvest, regardless of clover stand age, population density, or row width. However, clover was severely damaged when herbicide was applied to the narrow row spacing when using a wide band and severely compromised clover re-establishment.
White clover was planted at Fort Valley State University in the fall of 2014, but the cold winter caused injury and the clover stand was compromised. Therefore we will grow a summer annual crop in 2015 and the clover re-established this coming fall.
Three cover crop systems (cereal rye, crimson clover, and white clover living mulch) were established in the fall of 2014. Each plot contains 8 rows of corn. The cereal rye plots will receive a full complement of 250 lbs/A N, the crimson clover will received 100 lbs/A N, and the living mulch plots no N fertilizer. Mulch residue, living mulch clover, and corn will by systematically sampled within the outside 4 of the plots to determine N supply and uptake within each plot during the summer of 2015.
Matched watersheds were planted to one of two cover crops: cereal rye or white clover living mulch. H-flumes were instrumented with Teledyne sonic flow meters and ISCO Avalanche water samplers. Volume, sediments, and nutrients will be measured in water runoff over the course of the 2015, 2016, and 2017 growing seasons.

Impacts and Contributions/Outcomes

Our research project was featured on two newscasts for the Georgia Farm Monitor – a Georgia Farm Bureau production news show: (https://www.youtube.com/watch?v=o2JxVQv0dF0&list=UUEbWxEzz7YebK5eNyF8L9XA; http://www.youtube.com/watch?v=oOmSF8U3eJA&list=UUEbWxEzz7YebK5eNyF8L9XA&feature=share&index=3). Producers, research scientists, and county agents routinely watch the news show in order to keep up with emerging science and agricultural issues. Research from the living mulch project was presented at the joint Aflatoxin Mitigation Center of Excellence/Southeast Regional Aflatoxin Evaluation Consortium joint field day held at Tifton, GAon June 17/18, 2015. Their interest in the project is because of the likelihood that the living mulch system will suppress Aspergillus flavus spore dissemination and, thus, reduce incidence of aflatoxin contamination in corn. Approximately 70 researchers and corn producers attended the meeting. County agents helped organize a “Living Mulch Field Day” at the NW Georgia Branch Research and Education Center on August 14, 2014. The purpose of the field day was to demonstrate the system to interested producers (picture attached). Research results and pictures of plots from the living mulch system was presented to over 100 corn producers at the NW Georgia Corn/Soybean Update meeting held on January 23, 2015. Producer consensus was that weaning ourselves from expensive fertilizer and herbicide inputs is necessary and encouraged continued research emphasis.

The J. Phil Campbell Sustainable Research Center hosted a UGA “Corn Boil” on July 15, 2015. Fresh sweet corn was grown using the living mulch system for the corn boil meal, which consisted of hot dogs, homemade baked beans, chips, and drinks. Local industry leaders, farmers, grocers, Chamber of Commerce, State and Local politicians, and UGA faculty and administrators, were invited to attend. Over 100 guests attended the event. The system by which the sweet corn was produced was described at the field day.

Zachary Sanders, a graduate student working on the living mulch project, presented his research data to over 50 research and extension scientists at the 2015 Southern Agricultural Workers annual conference held on Feb 1-3, in Atlanta. He received Second Place among all graduate student oral presentations at the meetings.

In total, over 350 individuals had direct contact with the living mulch research/education project via county meetings, field days, and professional meetings. While it is difficult to assess the audience of the TV news stories, requests from Wisconsin, Iowa, Minnesota, Indiana, and Tennessee for additional information were received. Thus, the message of the living mulch system is reaching beyond the SSARE intended audience.

• Producers examining the impact of field corn shading clover, and its implications for N fertility.

Collaborators: