How Subsoilers Work in Various Soils - Study
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Transcript of How Subsoilers Work in Various Soils - Study
Acorn conference. November 23, 2015, Denis La France, dta, Expert in organic agriculture –
Anne Weill, agr., Ph.D.
! CETAB+ Team § Eve Cayer, agr., Sam Chauvette agr., M.Sc., Aurélie Demers, dta., Jean Duval, agr. Ph.D., Audrey Fréchette, Pierre Antoine Gilbert, agr., M.Sc., Denis La France, dta, Louis Rousseau, B.Sc., Audrey Ross, dta., Joshua Bougon-‐Ronin, Anne Weill Ph.D.
! Pierre Bournival, Eng., M.Sc. Teacher, Cégep régional de Lanaudière
! Sébastien Angers (Ferme Rheintal) ! Jean-‐François Arpin (Ferme l’Arche du Ruisseau)
! Simon Audette (Ferme Monlou et filles) ! John Bastian (Ferme Morgan) ! Alain Courchesne (Ferme Alain Courchesne et Rachel Cloutier)
! Jean Leclerc, dta., enseignant au Cégep de Victoriaville
! RDR Grains et semences inc.
! Agritex Yamaska (John Deere) ! Centre agricole Yamaska Inc (Case IH) ! Comptoir agricole de Sabrevois (Jo-‐ber) ! Kverneland Canada ! La Sole Inc.
! Often subsoiling effect disappear quickly
! Stabilizing with rapid root development helps maintain effects
! To subsoil established green manure (undersown clovers after cereal harvest) and hay fields so that roots colonize
! To subsoil established green manure (undersown clovers after cereal harvest) and hay fields
! Allow roots to stabilize loosened soil § Identify subsoilers that don’t damage the crops
§ Loosen the soil properly § Raise the yields in following years
! 3 straight-‐leg, narrow point subsoilers § Panbuster: developped in Ireland for grassland
§ Jober (Parabolic type) § Yeomans: Australian with possibility of adding weed-‐suppressing sweeps
! Sandy loam and loam on glacial till
30 cm
30 cm
! In sandy loam and loam on till, insufficient loosening
! One exception with Loam (till) ! Jober (Parabolic) works better
! Insufficient loosening of profile ! Solutions : Work deeper, closer spacing of tines, wider points
! Depth limited by: § Traction capacity of tractors § Machine design features: • Yeomans very difficult to pull • Panbuster conceived for work at 30-‐35 cm
! Deeper work = wider loosening
! Panbuster, Yeomans & farmer-‐owned machines § Unverferth-‐straight-‐tines, § John Deere et Will-‐Rich – curved-‐tines and winged
! More powerful tractors ! 3 farms (4 sites): Sandy loam, loam, compact
heavy clay, very compact heavy clay ! Ordered wide points on Panbuster-‐ received
wrong parts
! Only one machine works deeply (45 cm) § (Unverferth – narrow points)
! 350 Hp tractor-‐ soil very dry and hard
Only top part loosened-‐ Underneath smearing MOISTURE? SOIL TYPE? TINE GEOMETRY?
! Review of literature to better understand how tines and points work.
! Discussions with Dick Godwin. ! Planning a demonstation with wide range of subsoiler types to understand how tines and points work.
! Straight legs ! Curved legs ! Parabolic legs ! Narrow and winged-‐points ! Disk ripper
! In autumn 4 & 6 tine parabolic
Loosened soil
Soil compressed by the tines
Loosened soil
! Insufficient loosening of soil profile ! Tractors not powerful enough, often poorly balanced
! Easy to subsoil when not too compact, very difficult when very compact (80 Hp /leg is needed)
! Security systems are too week ! Smearing even after prolonged drought
25 cm
35 cm (one leg removed)
! Why deeper smearing in very dry soil? ! Narrow or wide points/wings? ! Straight, curved or parabolic legs? ! Spacing between legs? ! Best rake angle? ! How much lift height is best? ! How to succeed in really hard soil? ! Review of literature : answers come from work of Dick Godwin & Gordon Spoor
Working depth: 40 cm Central tines spacing OK Whole profile is loosened 40 cm deep Very good for reduced tillage systems
Parabolic V-‐frame
! Working depth -‐ Required power (hp/tine)
! 30 cm 50 HP ! 40 cm 75 HP ! 50 cm 125 HP
! We still have questions. ! Answers are site-‐specific ! See our document –CETAB+ site, edited by Anne Weill with help from Dick Godwin et Gordon Spoor
http://www.cetab.org/system/files/publications/weill_2015._guide_to_successful_subsoiling._cetab.pdf