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 field corn grown in the second year of the living mulch (LM) system.  Corn yields and clover re-establishment were greatest in narrow band and wide row treatments.  Soil water content was less in LM compared to other cover crops, but nitrate leaching was lower in LM.  Runoff, erosion, and nutrient loss was less in watersheds planted to (LM) compared to cereal rye.   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 from white 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 tested in the second year of the living mulch system. Clover was the sole source of N for the corn in this study. Clover regrowth in narrow rows and wide bands was slow in winter and corn yields were less (5.54-8.62 MT/ha) than in wide rows with narrow bands (11.09 MT/ha). Thus, it is imperative to use wide row spacing and narrow spray band patterns for the living mulch system.

Three cover crop systems (cereal rye, crimson clover, and white clover living mulch) were established in the fall of 2014. Corn was planted into each in spring of 2015. The cereal rye plots received a full complement of 250 kg/ha N, the crimson clover 100 kg/ha N, and the living mulch plots no N fertilizer. Mulch residue, living mulch clover, and corn were sampled weekly to determine N supply and uptake within each plot during the summer of 2015. Soil moisture was measured within and between rows and water use calculated for corn within each production system. Between row soil moisture was less in LM plots than other plots until 45 DAP, after which there were not differences. Corn height was less in the living mulch plots until tasseling but were not different thereafter. Shading of white clover occurred at 45 DAP at which time white clover responded be senescing leaves. As a result, N uptake was lower in LM until 60 DAP but was similar thereafter. Corn yield (11.34 MT/ha) and water use efficiency (35 kg/ha/mm water) were not different among treatments.

Matched watersheds were planted to one of two cover crops: cereal rye or LM. H-flumes were instrumented with Teledyne sonic flow meters and ISCO Avalanche water samplers. Volume, sediments, and nutrients were measured in water runoff over the course of the 2015 growing season and compared to historical data from each. Historically the watershed planted to LM had 25% more runoff than the watershed planted to cereal rye. However, the difference between the two watersheds in 2015 was 5%. Thus, LM reduced water runoff. The watershed panted to LM historically had twice as much sediment in runoff than the watershed planted to cereal rye. Both cover crops reduced sediment in runoff by 90%+ compared to historical losses. However the LM watershed had 75% less sediment than the cereal rye watershed, and sediment losses in the LM watershed were 99.9% less than historical values. Nutrient losses from runoff were similar regardless of cover crop, primarily because sediment in the LM was nutrient rich organic matter.

Impacts and Contributions/Outcomes

The J. Phil Campbell Sustainable Agricultural Research Center hosted a UGA “Corn Boil” on June 29, 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.

The J. Phil Campbell Sustainable Agriculture Research Center hosted 3 field days over the course of the growing season. The field days had stops at the LM plots, cover crop plots, and organic agriculture plots. A total of 218 producers attended the field days. Questionnaires were distributed to growers and requested feedback for each stop at the field day. The LM plots consistently received the highest ratings of all stops on the tours.

Josh Andrews, a graduate student working on the living mulch project, presented his research data to over 50 research and extension scientists at the 2016 Southern Agricultural Workers annual conference held on Feb 6-8, in Atlanta. He received Third Place among all graduate student oral presentations at the meetings.

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