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Soil Management and Crop Biomass Removal Impacts on Soil Organic Matter Content. Krisztina Eleki, Richard M. Cruse , László Fodor, Lajos Szabó, and Sándor Holló. ????????????????????????? . Can we remove crop biomass and conserve soil organic matter content (humus)?.
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Soil Management and Crop Biomass Removal Impacts on Soil Organic Matter Content Krisztina Eleki, Richard M. Cruse, László Fodor, Lajos Szabó, and Sándor Holló
????????????????????????? • Can we remove crop biomass and conserve soil organic matter content (humus)?
Why is this an important question? • The U.S. government “Vision for Bioenergy and Bio-based Products in the United States” – from biomass by 2030 • 5% of power, • 20% of transportation fuels and • 25% of chemicals
Why is this an important question? • Much of biomass will come from agricultural land
What do we understand? • Soil Organic Matter very important • Sustainability • Soil quality • Crop production • Soil and water conservation
What do we understand? • Soil organic matter if organic matter added* • Soil organic matter if biomass removed* * For simple cropping systems – one or two crop, one or two fertilizer management treatments
We do not understand interactions! • Crop type • Crop rotations • Fertilizer management – root mass and microbial activity • Manure applications – organic matter additions • Tillage – microbial activity Root morphology (form) effects
Key – seeking evidence • Can we harvest crop biomass? IF YES • How much can we harvest? • What is best management?
Objective • Determine the effect of management practices on Soil Organic Matter (SOM) change with time • Crop rotation • Fertilizer management • Manure application • Crop biomass removal
Methods • Location – Kompolt, Hungary, Rudolf Fleischmann Research Station - 47°45' N and 20°15' E • Multifactor experiment – four replications • Crop rotations (main plots) - 3 • Fertilizer rate (splits of main plots) - 12 • Fertilizer management (second split) - 3
Methods (cont.) • Fertilizer rates – 12 • Commercial fertilizer rates • Manure application • Biomass removal vs. no removal
Methods (cont.) • Experiment 1961 – 2001 • SOM measured: 0 – 30 cm depth • Analysis of Variance
Results P < 0.0008 Fertilizer 1961 SOM = 2.58%
Results P = 0.08 Four Crop Rotation Cont. Corn 1961 SOM = 2.58%
Results P < 0.0001 4 YR Corn, 4 Alfalfa 4 YR app., 4 YR none Yearly Application
Results P < 0.0008 No Manure Biomass Removal Manure – 35.2 Mg/ha Biomass Removal No Manure Biomass Incorp.
Conclusions • Rotations ???? • Fertilizer management • Manure applications • Biomass removal
Next Step • Test 2 soil carbon models against this data • Use best model to estimate SOM change across landscape in Iowa • With different management • With biomass removal