1 Soil Carbon Sequestration: Long-term Effect of Tillage and Rotations Charles W. Rice and Karina Fabrizzi October 28-30, 2008 Kansas State University

Global economic mitigation potential for different sectors at different carbon prices IPCC, 2007

Agriculture A large proportion of the mitigation potential of agriculture (excluding bioenergy) arises from soil C sequestration, which has strong synergies with sustainable agriculture and generally reduces vulnerability to climate change. Agricultural practices collectively can make a significant contribution at low cost –By increasing soil carbon sinks, –By reducing GHG emissions, –By contributing biomass feedstocks for energy use IPCC Fourth Assessment Report, Working Group III, 2007

Agriculture Cropland –Reduced tillage –Rotations –Cover crops –Fertility management –Erosion control –Irrigation management Rice paddies –Irrigation –Chemical and organic fertilizer –Plant residue management No-till seeding in USA Rice fields in The Philippines Maize / coffee fields in Mexico Agroforestry –Improved management of trees and cropland

Agricultural Management Strategies for C Sequestration Develop Agricultural Management Programs that:

Soil Microbial Activity Soil Organic Matter (C) CO 2 Harvestable Yield Sunlight Climate Soils Management

Potential C sequestration in U.S Lal et al., 1999, Post et al.,2004

8 Corn production in NE Kansas Continuous corn 168 kg N/ha Tillage Systems –No-tillage –Conservation tillage (Chisel-disk) 15 year analysis

Soil C stocks after 18 years 9 * * * Nicoloso et al., 2008

Tillage effects on soil organic C by depth, Minnesota: 14 y continuous corn Mg C/ha/cm DepthNo-tillPlow ** ** 0-45 (Mg/ha)160133** 10 Huggins et al., 2007

E A Change in management Years of cultivation SOC levels (Mg C ha - 1 ) O

Soil C sequestration rates for 15 years (Mg C/ha/y) DepthFertilizer N Tilled Fertilizer N No-till Manure N Tilled Manure N No-till cm NT > Tilled, but tilled had some increase Added C (manure) is less conserved in tilled What is baseline? Nicoloso et al., 2008

E D C A Change in management Years of cultivation SOC levels (Mg C ha - 1 ) O

Net effect of NT for 15 years NT (0-15y) –T (0-15y) DepthNo N 0.5 Fertilizer N 0.5 Manure NManure N cmMg/ha/y Nicoloso et al., 2008

Carbon sequestration rate (C rate) expressed in equivalent mass (Mg C/ha/y) to a 30 cm depth except for Hayes (15 cm) LocationRotationDurationCTRTNT HayesWheat-Sorg-F37 y ParsonSorg-Soy20 y AshlandAverage29 y TribuneWheat-Sorg-F15 y Fabrizzi, 2006

8/9/ :1 Line Intergovernmental Panel on Climate Change (IPCC): 1.1 for CT to NT West and Post (2002): 1.16 for CT to NT Fabrizzi, 2006

Carbon sequestration rate (C rate) expressed in equivalent mass (Mg C/ha/y) to a 15 cm depth as a function of N rate (kg N/ha/y) located Hayes, Kansas, USA RotationDuration0 N22 N45 N67 N Wheat-Sorg-F37 y Fabrizzi, 2006

Carbon sequestration rate (C rate) expressed in equivalent mass (Mg C/ha/y) to a 30 cm depth for Manhattan, KS USA Rotation Continuous Soybean0.066 Continuous Sorghum0.292 Continuous Wheat0.487 Soybean - Wheat0.510 Soybean - Sorghum Fabrizzi, 2006

Physical Protection Chemical Microbial composition and activity Substrate quality Plant characteristics H2OH2O Temperature Clay Biological factors Organics Clay Organic C CO 2 O2O2 Disturbance Conservation of Soil Carbon Hierarchy of importance Mineralogy

Fungal Role (18:2w6 biomarker) Significant tillage X residue interaction (p<0.05) CT + No RCT + ResidueNT + No RNT + Residue c* a b c Mole Fraction Frey et al. (1999) found greater fungal networks optically in NT as compared to CT for the same soil. White and Rice, 2007

Fabrizzi, 2006

Soil Organic Carbon Microbial Activity Nutrient Cycling Soil Structure Soil Biodiversity Water Erosion & Availability Gaseous Emissions Plant Growth Yield Environmental Services Sustainability

No-Tillage Cropping Systems Conservation Agriculture Restores soil carbon Conserves moisture Saves fuel Saves labor Lowers machinery costs Reduces erosion Improved soil fertility Controls weed Planting on the best date Improves wildlife habitat

Summary Soil C sequestrationSoil C sequestration –Need to examine the system Less disturbanceLess disturbance Organic C inputsOrganic C inputs –No-tillage must be combined with residues Residue removal in no-till may be worst than tillage with residueResidue removal in no-till may be worst than tillage with residue Agricultural soil C sequestrationAgricultural soil C sequestration –Keeps land in production in some cases –In many cases increases profitability for the farmer –Provides other environmental benefits to society Soil and Water quality (less runoff, less erosion)Soil and Water quality (less runoff, less erosion) –May help adapt to climate change as well as mitigate

Websites K-State Research and Extension Chuck Rice Phone: Cell:

8/9/ TreatmentScenarioRate (Mg C/ha/y) State Eliminate summer fallow 3-year system 4-year system Continuous cropping Eastern Colorado NT (corn)NT 150 N Fert0.80NE Kansas RotationsCT - NT wheat CT - NT sorghum CTsorg/NTwheat to NT sorg/wheat SC KS CRP0.80NE