Identification of Factors Affecting Carbon Sequestration and Nitrous Oxide Emission in Three Organic Cropping Systems

USDA-NIFA Grant Award10/2011 – 08/2014

Principle Investigator: Tim Reinbott, University of Missouri

Co-Investigators:Bob Kremer, USDA-ARS

Newell Kitchen, USDA-ARS

Debi Kelly, University of Missouri Extension

Establishing organic research at the University of Missouri and utilizing on-farm research and demonstrations with cooperating farmers is a crucial step in developing local and regional outreach programs for organic agricultural practices.

The overall goal of this research project is to improve the competitiveness of organic crop producers in Missouri by providing research into cropping systems that will help them maintain or increase grain productivity, suppress weeds and provide fertility while reducing their negative impacts on water, air and soil quality.

Specific goals of the study:

  • Provide data on nitrous oxide emissions in corn-soybean-wheat rotations using conventional tillage vs. no-till and using cover crops in both tillage schemes.
  • Compare tillage and cover crop practices to optimize carbon sequestration and reduce carbon dioxide emission in Missouri’s claypan soils
  • Expand our knowledge of cover crops that can be incorporated into organic agriculture for nitrogen, weed suppression and soil quality specific to Missouri’s diverse soils and climatic conditions.
  • Determine how much organic compost is required in addition to legume cover crops to maximize grain yield
  • Utilize project data to inform University Extension and NRCS personnel and develop outreach programs for organic producers in Missouri and those considering organic production.

The main part of this study will take place at the University of Missouri Bradford Research and Extension Center (BREC), located 5 miles east of Columbia, MO. Soils at this site are primarily Mexico silt loam (fine, smectitic, mesicVerticEpiaqualfs).

MU Research Grain Production Plots:

An area located at BREC that has been in a conventional corn/soybean rotation is divided into three 40 x 30 ft (12 x 9 m)main plots of either:

1. Tillage without cover crop;

2. Tillage with cover crop;

3. No-tillage with cover crop.

Each main plot is divided into four split plots of 10 x 30 ft (3 x 9 m) of four rates of composted manure from a local organic poultry farm in California, MO. Three studies with corn (Zeamays), soybeans (Glycine max (L) Merr.) and wheat (Triticumaestivum) run simultaneously beginning in the fall of each harvest year. In mid October, wheat planted with a grain drill at 7.5 inch row spacing (0.2 m) into main plots that have either been tilled (treatments 1 and 2) or left untilled (treatment 3). After wheat harvest in late June, a crop of buckwheat (Fagopyrumesculentum) is planted and tilled under in late August. A rye/hairy vetch mixture consisting of common rye, 60 lbs/acre (67 kg/ha), and inoculated common hairy vetch, 30 lbs/acre, (33.5 kg/ha) is drilled in late Aug/early September in those plots that will be followed by corn in the spring. Winter cereal rye will be planted in late Sept/early Oct at 90 lbs/acre (101 kg/ha) in those plots followed by soybeans in the spring. Cover crops will be flail mowed in early May ahead of corn and mid May ahead of soybeans. Corn will be planted in 4 rows of 30 inch (76 cm) row spacing with an organic, non-GMO hybrid corn variety. Soybean plots will be planted with an organic, non-GMO soybean variety in four 30 inch rows in tilled plots and 15 inch rows in no-till plots, which is the best management practice for weed control in no-till.

Each tillage treatment will be divided into four 10 x 30 ft (3 x 9 m) plots (split plots), organic compost (3-3-2) added at rates dependent upon the crop, plot and need. The base N fertility for wheat will be 80 lb N/acre (90 kg/ha), and for corn 150 lb/acre (168 kg/ha), Compost rates will be determined to achieve N rates of 0, 40, 80, and 120 lbs N/acre in wheat and 0, 75, 150, and 225 lbs N/acre in corn. Compost will be added to soybean at the same rate as wheat.

Analyses Planned a/o Underway:

Soil Organic Carbon Analyses

Nitrous Oxide, Carbon Dioxide Gas Sampling

Global Warming Potential

Soil Biological Activity

Soil Microbial Biodiversity

CropNutritive Value

Cover Crop Screening:

Soil moisture

Weed suppression

Plant nutrient cycling

Economic Analysis

Outcomes:

  • Increased understanding of tcontribution of organic cropping systems to production or mitigation of the greenhouse gases, CO2 and N2O.
  • Increased knowledge of integrating cover crops and no-till in an organic cropping system.
  • Provide organic producers, and those considering organic production, with increased knowledge on using cover crops and manure for nitrogen fertilization and weed suppression.
  • Increased knowledge of Extension educators, NRCS and other agency partners in Missouri on basic information on certification and organic grain crop production; serve as information source for future producers who have questions about organic production.

2012 / 60 lbs rye 30 lbs vetch/acre / 90 lbs/acre
Plot layout / Rye/Vetch mix / Rye / Buckwheat
CORN / SOYBEAN / WHEAT
NE / SE
20 FT / 3106 2 / 3105 3 / 3104 1 / 3103 2 / 3102 3 / 3101 0 / 2106 0 / 2105 1 / 2104 3 / 2103 0 / 2102 2 / 2101 3 / 1106 3 / 1105 2 / 1104 0 / 1103 3 / 1102 1 / 1101 0
20 FT / 3107 1 / 3108 0 / 3109 0 / 3110 3 / 3111 2 / 3112 1 / 2107 3 / 2108 2 / 2109 2 / 2110 1 / 2111 1 / 2112 0 / 1107 0 / 1108 1 / 1109 1 / 1110 2 / 1111 2 / 1112 3
20 FT ALLEY / 15 FT / 15 FT
3206 0 / 3205 1 / 3204 2 / 3203 3 / 3202 1 / 3201 3 / 2206 2 / 2205 0 / 2204 0 / 2203 1 / 2202 3 / 2201 2 / 1206 0 / 1205 3 / 1204 2 / 1203 1 / 1202 3 / 1201 2
3207 2 / 3208 3 / 3209 1 / 3210 0 / 3211 0 / 3212 2 / 2207 3 / 2208 1 / 2209 2 / 2210 3 / 2211 1 / 2212 0 / 1207 1 / 1208 2 / 1209 3 / 1210 0 / 1211 0 / 1212 1
3306 0 / 3305 1 / 3304 1 / 3303 2 / 3302 2 / 3301 3 / 2306 2 / 2305 3 / 2304 1 / 2303 2 / 2302 3 / 2301 0 / 1306 3 / 1305 1 / 1304 2 / 1303 3 / 1302 1 / 1301 0
3307 3 / 3308 2 / 3309 0 / 3310 3 / 3311 1 / 3312 0 / 2307 1 / 2308 0 / 2309 0 / 2310 3 / 2311 2 / 2312 1 / 1307 2 / 1308 0 / 1309 0 / 1310 1 / 1311 3 / 1312 2
3406 2 / 3405 1 / 3404 0 / 3403 3 / 3402 3 / 3401 2 / 2406 3 / 2405 2 / 2404 2 / 2403 1 / 2402 1 / 2401 0 / 1406 0 / 1405 1 / 1404 3 / 1403 0 / 1402 2 / 1401 3
3407 3 / 3408 0 / 3409 1 / 3410 2 / 3411 0 / 3412 1 / 2407 0 / 2408 1 / 2409 3 / 2410 0 / 2411 2 / 2412 3 / 1407 3 / 1408 2 / 1409 2 / 1410 1 / 1411 1 / 1412 0
till with no cover crop / 0= 0 compost
1= level 1 compost
till with cover crop / 2= level 2 compost
3= level 3 compost
no-till with cover crop