Tillage and Cover Crops

Transcription

1 Tillage and Cover Crops 2012 LOUISIANA AGRICULTURAL TECHNOLOGY & MANAGEMENT CONFERENCE Paragon Casino Resort Marksville, LA February 15-17, 2012 Kip Balkcom Research Agronomist USDA-ARS National Soil Dynamics Laboratory Auburn, AL

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3 Soil C is the basis of Soil Quality/Productivity NH and NO, 4 3 P, K, Ca, Al, CEC Microbial Biomass C and N N Soil Respiration Biomass C to TOC ratio mineralized Respiration to Biomass ratio Total Organic C and N capacity retention content Water Aggregate Stability Size Distribution Bulk Density Soil Strength Infiltration from Doran et al., 1993

4 How to increase soil C and improve soil quality? Conservation Tillage with Cover Crops Conservation System

5 Conventional Tillage Promotes Soil Erosion

6 Manage compaction...

7 Non-inversion Tillage

8 Tillage and rye cover crop effects on SOM after 5 y 0 2 SOM (%) No-Till w/o cover Conventional w/o cover No-Till w/ cover Fall Paratill w/ cover Decatur silt loam

9 Effect of cropping/tillage system on soil C from an eroded Ultisol in Georgia. Grain sorghum no-till into crimson clover mm mm mm conversion to conventional till soybean Year Bruce et al., 1995

10 Field Scale Research Conventional Conservation Conventional Conservation Conventional { { { Depression (11%) Conventional: 2937 lb/a Conservation: 3255 lb/a Plateau (14%) Conventional: 2651 lb/a Conservation: 3032 lb/a } } Conventional Conservation Eroded Slope (16%) Conventional: 2440 lb/a Conservation: 2830 lb/a Conservation Conventional Conservati Conventiona

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12 What is a Cover Crop? A crop whose main purpose is to benefit the soil and/or a subsequent crop in one or more ways, but is not intended to be harvested for feed or sale. Courtesy: Harry Schomberg, USDA-ARS

13 High Residue Cover Crop

14 Why use Cover Crops? Erosion control Soil and water quality improvement Increased water infiltration Minimize nutrient loss Soil organic carbon

15 Tennessee Valley-Clay Soils No-Till w/o Cover Crop

16 Tennessee Valley-Clay Soils No-Till with Cover Crop

17 Planting Date - Clover Biomass PD 1 PD 2 PD 3 PD 4 PD EVS2004 EVS2005 TVS2004 TVS2005 JAY2005 Courtesy: Andrew Price

18 Winter Cover Crop Biomass and Weed Suppression 1200 Weed biomass (kg/ha a) Rye biomass (kg/ha)

19 Cover crop planting date affects rye biomass and pigweed density Rye Biomas ss (kg/ha) PD1 PD2 PD3 WF CT Treatment Pigweed Density (plants s/ha)

20 Cover Crop Fertilization 90 lb N ac -1 0 lb N ac -1

21 N Fertilizer Effects on Rye Cover Crop Biomass Production Rye biomass s, kg ha Nitrogen rate, kg ha -1 WGS Headland, AL

22 Rainfall Simulation Study...

23 Tillage and residue effects on infiltration of a Coastal Plain Soil (2-inch rain event) days *No Deep Tillage days 0 No Till w/ residue No Till w/o residue Conventional Tillage

24 Soil Water Conservation Plot 141 Plot 142

25 MAY 1 Timing Termination

26 Biomass Production Time of Termination lb ac -1 Biomass, Rye before Corn Wheat before Corn Rye before Cotton Wheat before Cotton

27 Methods of Termination Physical methods Incorporation Mowing Mechanical Rolling

28 Roller Variations

29 Roller Variations

30 Roller Variations

31 Roller Variations

32 Rollers/crimpers developed at the NSDL Smooth roller with crimping bar U.S. Patent pending (Kornecki, et al.) Two-Stage roller/crimper U.S. Patent pending (Kornecki) Roller for elevated beds: U.S. Patent allowed (Kornecki) One row two furrows Less vibration transferred to tractor, adjustable crimping force, a unique crimping bar design to accommodate for uneven soil surface Compact design, with adjustable crimping force. Drum with crimping bars isolated to minimize vibration. Intended for small vegetable farm operation: Two rows three furrows Designed both for field and vegetable crops

33 Ripper Modification

34 Planter Attachments

35 Summary Plant covers in a timely fashion. Consider additional N fertilizer for small grain cover crops, especially if residual N is low. Terminate covers ~ 3 weeks ahead of anticipated planting date to allow soil moisture recharge and reduce problems with equipment operation. Take advantage of equipment modifications to facilitate tillage and/or planter operations in heavy residue.

36 Tillage and Cover Crop Resources Managing Cover Crops Profitably, 3rd ed. Sustainable Agriculture Network. UC SAREP Cover Crop Resource Page National Sustainable Agriculture Information Service (ATTRA) Schomberg, H.H., and K.S. Balkcom. Cover crops [Online]. Available at: crops.html