Performing Department
Crop Science
Non Technical Summary
Organic grain cultivation continues to increase in the Southeastern and mid-Atlantic regions (Dimitri 2008; Hamilton and Rzewnicki 2007a). In North Carolina, the number of organic field crop growers has expanded considerably within the last two years and farms are rapidly expanding their acreage. An informal census in North Carolina estimates the acreage of corn, soybean, and wheat expanded from 950 acres in 2006 to 12,000 acres in 2011. Pest management and the use of crop breeding to address pests are cited by these farmers as one of their top concerns during panel discussions and in surveys. Other concerns are reducing tillage, and diversifying the number of organic crops. The public at large is also increasing interested in the environmental impact of agriculture, include the greenhouse gas emissions from farming. This project coalesces research on all of these topics.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Goals / Objectives
Objectives: 1. Collaborate with plant breeders to develop cultivars suitable for organic systems. 2. Reduce tillage on organic farms. 3. Find alternative crops to lengthen rotations and enhance profitability of North Carolina's organic farmers. 4. Determine the impact of organic weed management practices on nitrogen and carbon cycling and subsequent greenhouse gas emissions.
Project Methods
PLANT BREEDING Host both live and videoconference meetings for breeders and farmers to define breeding targets and convey progress. Screen breeding lines submitted by breeders around the region for specific farmer- defined breeding targets utilizing protocols we have developed over the last three years. Screen advanced generation material submitted by breeders around the region for performance in organically managed field trials. REDUCING TILLAGE We will establish three research sites at research stations in distinct geographic regions of the state. We will roll cover crops and plant corn and soybeans at the appropriate time for each region. Some of the legume cultivars will not have flowered yet while others will. We will evaluate the cover crop stands, effectiveness of roll-killing the cover crop, and the cover they provide as mulch to the grain crop. Farmers attending field days will be able to see the effect of these differences in flowering time on how well the cover crop is killed. ALTERNATIVE CROPS Canola North Carolina has very little experience with this crop under conventional conditions, and no experience organically. We have, however an excellent opportunity with a local crusher offering organic contracts. AgStrong, in northeast Georgia, is offering North Carolina growers contracts that appear highly profitable assuming we can produce reasonable yields here. The first research issues were established by a meeting between farmers and buyers and the following experimental protocol was laid out: Seeding Rates: 3,6,9,12 seeds per square foot Row Spacing: 6.7", 13.3", 26.7" Cultivation: between row sweep cultivator 1 to 2 times on 26.7" row spacing Multiple locations and years of this experiment will establish expected yield for organic farmers and give them basic guidance on production practices. Stevia We are exploring multiple means of producing this crop both conventionally and organically given the market demand for both. The following treatment design will be employed: Four weed control strategies. Two will be herbicide based and two will be organic. Three disease management strategies: a) no treatment check, b) scout and spray with organic fungicides if needed, and c) scout and spray with conventional fungicides if needed 2 harvest schedules: 1 vs. 2 harvests WEEDS AND GREENHOUSE GASES Objective: Assess the impact of cover crops and weeds on soil C and N sequestration and soil N2O emissions. Hypothesis: Cover crops and weeds enhance the buffering capacity of organic systems for N retention, while increasing organic C inputs. Six treatments in a long-term systems trial will be studied in the presence and absence of weeds. Static chambers will be used for the measurement of N2O. These measurements will follow the standard technique of covering rings installed in the plots with chamber of known volume for set periods of time. Establishment of linear rate of change of concentration in N2O within the chamber allows calculation of flux. Gas samples obtained from the static chambers will be analyzed using a gas chromatograph equipped with an injection loop and electron capture detector.