Cover Crop Impact on Carbon and Nitrogen. Michael Plumer Conservation Agriculture Illinois Council on Best Management Practices

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1 Cover Crop Impact on Carbon and Nitrogen Michael Plumer Conservation Agriculture Illinois Council on Best Management Practices

2 Measuring soil changes

3 Adding roots and OM through pan layers to subsoil

4 Soil probe sample we are tracing the ryegrass roots 4

5 Changes to OM in fragipan (originally 1.4% to 5 now 3.3% to 12 )

6 Development of OM to depth of 12

7 Corn rooting beyond 66 adds OM into the subsoil

8 Soil Density (g/cm 3 ) all no-tilled 9+ years Ryegrass cover crop No cover crop for 6 years * * * sig..05 M Plumer

9 No-till carbon Bulk density was: 1.1gm/cm 3 in top gm/cm 3 to 8" in depth in 2008 ( all surface duff or residue was removed before any sampling) Carbon rate of increase due to changing nitrogen application in 1992 to injected instead of ammonium nitrate surface applied total carbon in top 14" #/a 2008 no-till started in 1969 was 99,322#/a An increase of 59,814 # in the next 16 years 2008 no-till started in 1992 was 71836#/a carbon

10 Looking at soil incremental changes over time Soil depth no-till no-till carbon#/a carbon#/a

11 Cover crop contribution depends on Variety/combination Indy-- ryegrass/crimson/radish Mature yield #/a Gulf Mature top growth yield At full heading #/a Wirth ER Mature top growth yield At full heading #/a Gulf RootMax Root mass at 4 top height March 16th Root mass at 4 top height March 16 th 1084#/a 1854 #/a Amount of dry matter produced will impact OM change

12 Soybean root following previous root channel

13 20 To to to to 50 6 years cover crops and no-till corn root development in clay pan soils

14 Corn after Corn no-tilled into mature cereal rye, on June 3 rd, good yields in October

15 Residue after 12 years continuous BTcorn and Hairy vetch every year shows decomposition level in late June, significant biological activity

16 Soil changes by hairy vetch and radish row

17 Soil tilth from 12 years of cover crops-annual ryegrass, and/or crimson clover Originally 1.2% OM claypan soil, Currently 3.2% OM

18 Soil after 8 years of cover crop- annual ryegrass and no-till --OM changed from 1.4% to 3.0%

19 Corn root depth after 4 years of cover crops In fragipan soil, adding OM to subsoil, improving crop growth and rooting

20 Impact of cover crop 2012 Cover crop Harvest population Yield bu/a Ryegrass/crimson clover late killed- moisture deficit, no rain 31, Windham winter pea 30, Ryegrass /crimson 29, Ryegrass/crimson/radish 30, hairyvetch,/ryegrass/radish 31, Hairyvetch/ryegrass/radish early killed 29, Nitrogen: 50#/a at planting, 70#/a side dressed as 28% lsd bu/a

21 Comparison cover crop vs bare soil no-till corn after corn 2012 treatment Harvest population Yield bu/acre Annual ryegrass 29, Bare corn stalks 29, Lsd Nitrogen: 50#/a at planting ; 100#/a side dressed

22 Late corn Planting into Mature cover crops Tmt Yield in bushels/acre Bare soil 88.8 Cereal rye- full headed Annual ryegrass headed Annual ryegrass boot stage lsd Late planted June 3 rd Nitrogen limited to 98#/a No-till corn no starter Corn on corn Low nitrogen rate to show cover crop effect Plumer, 2011

23 Nitrogen availability Depends on cover crop stage of growth Vegetative grass stage yields most available Legume is based on total top growth Leachable from top growth Residue must decompose to recover all nutrients Amount of nitrogen may depend on variety 23

24 September 10 Legume planting study results, on May 12 DM#/acre nitrogen/a n test % austrian winter pea Mihi Persian clover Dixie Crimson Clover common crimson clover Kaup hairy vetch Vf-1 Forage First hairy vetch Steve Groff hairy vetch Pennington Vp-07 hairy vetch inoculated Pennington Vp-08 hairy vetch inoculated Pennington Vp-07 hairy vetch Pennington Vp-08 hairy vetch albert lea hairy vetch

25 Carbon Nitrogen Ratio Cover Crop Carbon to nitrogen Oilseed radish 19:1 Cereal rye vegetative stage 14 :1 Cereal rye boot stage 40:1 Hairy vetch 10:1 early 15:1 at bud/bloom Crimson clover 15:1 Annual ryegrass 15:1 vegetative 35:1 at heading

26 2012 nitrogen issues Extensive testing in central Illinois shows: High nitrogen levels 1-12 AND Test levels running 40#/a to 90#/a in soil profile Most of nitrogen in leachable form Setting up for huge nitrogen losses from tile lines KIC 2025 is heavily promoting cover crops to capture nitrogen Recommending soil tests before considering fall nitrogen application

27 Which cover crops to capture Nitrogen Oilseed radish but planting date is now past for best effectiveness Very effective in capturing N Oats- need planted soon Annual ryegrass very effective, seeding time ends next week, or dormant seeding February Cereal rye the late plant option Can plant till/into November

28 Cover Crop Picking up excess nitrogen from Anhydrous tracks after corn Upton farm Frost damage on lush growth Taylor farm Protecting ground water by holding left over nitrogen till spring 28

29 Nitrogen Uptake Continuous no-till Corn after Corn 200#N/a = 215 bu/a 3642 #/A. annual ryegrass Jan #/a of Nitrogen from ryegrass water leachable Leached out of ryegrass with 2 of water applied

30 Bare fallow U of Ill.

31 Capture nitrogen now Promote cover crops NOW Education is extremely important to avoid a huge water quality issue next spring Currently major issue in finding enough cover crop seed Huge increase in cover crop acres