Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Subsoil manuring - Renick Peries (DEDJTR)

372 views

Published on

What is subsoil manuring?
• A mechanical/engineering intervention
• Large volumes (10-20 t/ha) of Nitrogen rich manures
placed within the clay matrix of soil in a single deep
ripping operation.

Published in: Science
  • Be the first to comment

  • Be the first to like this

Subsoil manuring - Renick Peries (DEDJTR)

  1. 1. Subsoil Manuring Crop and Soil responses to an innovative practice  in the low‐medium rainfall regions of Victoria Renick Peries, Melissa Cann & Darryl Pearl (DEDJTR) & Jaikirat S Gill & Peter Sale (LTU) 
  2. 2. What is subsoil manuring? • A mechanical/engineering intervention • Large volumes (10-20 t/ha) of Nitrogen rich manures placed within the clay matrix of soil in a single deep ripping operation.
  3. 3. The  problem with dense clay subsoils (HRZ) Low macro‐porosity   ……roots cannot breathe High bulk density        ……roots struggle to penetrate Low infiltration            ……cannot capture rainfall in subsoil Frequently sodic ….. high sodium…ESP% > 15%
  4. 4. OUR APPROACH TO SOLUTIONS? (VICTORIAN HRZ VS LOW TO INTERMEDIATE RAINFALL REGIONS) • Low water productivity despite high rainfall • Dense clay subsoils with low macro-porosity ?
  5. 5. Increasing the capacity to store PAW: Catch more, store more grow more
  6. 6. Soil pit showing manure placed at depth Photo: courtesy of SFS
  7. 7. subsoil manuring- benefits & setbacks • Improves connectivity between topsoil & subsoil •Improves aeration & conductivity •Improves bucket size •Improves soil biology ? •Improves yield & WUE •Currently Expensive
  8. 8. Subsoil manuring: how does it transform clay? manure microbes polysaccharides + clay particles clay aggregates Roots clay particles clay aggregates
  9. 9. SSM plot    30‐40 cmControl plot   30‐40 cm ……… 4 years after treatment The amended clay layer is transformed Increased macro‐porosity   ……roots can now breathe, less waterlogging Lower bulk density               ……roots readily penetrate into subsoil Rapid infiltration                   ……readily capture rainfall in subsoil
  10. 10. Crop and soil responses in the low-intermediate rainfall zone
  11. 11. Rainfall @ the Mallee trial sites 2014 Site Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec RF(T) RF(GS) Ouyen 3 64 6 63 21 10 17 4 62 3 25 15 292 179(84) Hopetoun 8 9 14 64 22 21 23 8 14 2 26 7 211 154(92) Charlton 5 8 36 56 23 35 24 7 13 11 41 16 275 169(57) 2015 Site Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec RF(T) RF(GS) Ouyen 30 6 0.4 38 22 31 18 14 12 10 33 3.6 219 146(69) Hopetoun 40 15 0.4 21 26 32 19 15 27 26 38 64 324 165(98) Charlton 37 14 8 19 25 31 28 26 17 6 24 8.2 243 152(51) Site Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec L‐T/(GS) mean Ouyen 20.9 24.3 20.0 21.7 31.5 29.2 30.6 32.2 32.6 34.4 27.8 25.6 331.1 (212) Hopetoun 33.9 14.2 17.6 21.5 25.0 24.1 26.3 24.8 23.2 22.7 29.9 29.3 293.3 (168) Charlton 24.3 27.2 28.3 32.2 42.7 48.1 43.2 45.2 42.6 41.8 28.4 26.8 430.8 (296)
  12. 12. YEAR Rainfall period Rainfall (mm) Decile ranking Comments Summer (Dec.‐Feb.) 91 7.3 Autumn (Mar.‐May) 90 7.5 2014 Winter (June‐August) 30.7 0.4 The 4th driest winter on record from 1913 Spring (Sept.‐Nov.) 90 5.6 Growing Season (Apr‐Oct.).) 179 3.9 Total Annual (Jan.‐Dec.) 293 3.9 Summer (Dec.‐Feb.) 51 3.9 Autumn (Mar.‐May) 61 4.8 2015 Winter (June‐August) 63 2.3 Spring (Sept.‐Nov.) 56 2.5 Growing Season (Apr‐Oct.) 146 1.8 Total Annual (Jan.‐Dec.) 218 1.3 Mean annual rainfall  (1880‐2015)        330 Amounts and decile rankings for seasonal rainfall at Ouyen in 2014 and 2015, from Ouyen Post Office recording station
  13. 13. YEAR Rainfall period Rainfall (mm) Decile ranking Comments Summer (Dec.‐Feb.) 17 0.6 The second driest on record since 1998. Autumn (Mar.‐May) 100 8.0 2014 Winter (June‐August) 52 1.7 . Spring (Sept.‐Nov.) 42 0.6 The second driest on record since 1998. Growing Season (Apr‐Oct.).) 154 2.3 Total Annual (Jan.‐Dec.) 211 1.3 The 3rd driest since on record since 1998. Summer (Dec.‐Feb.) 62 6.4 Autumn (Mar.‐May) 150 10 The wettest on record since 1998. 2015 Winter (June‐August) 76 2.4 . Spring (Sept.‐Nov.) 49 2.6 Growing Season (Apr‐Oct.) 155 2.7 Total Annual (Jan.‐Dec.) 246 3.3 Mean annual rainfall  (1904‐2015)        502 Amounts and decile rankings for seasonal rainfall at Hopetoun in 2014 and 2015 measured at the nearby weather station at Wirrbibial Downs.
  14. 14. YEAR Rainfall period Rainfall (mm) Decile ranking Comments Summer (Dec.‐Feb.) 22 1.2 Autumn (Mar.‐May) 113 6.3 2014 Winter (June‐August) 66 0.8 The 5th driest on record since 1952. Spring (Sept.‐Nov.) 74 2.7 . Growing Season (Apr‐Oct.).) 223  1.7 Total Annual (Jan.‐Dec.) 279 1.3 . Summer (Dec.‐Feb.) 64 4.8 Autumn (Mar.‐May) 52 2.1 2015 Winter (June‐August) 85 1.6 The 4th driest on record since 1956. Spring (Sept.‐Nov.) 47 0.8 The 4th driest on record since 1952. Growing Season (Apr‐Oct.) 176 0.9 The 5th driest on record since 1952. Total Annual (Jan.‐Dec.) 243 0.9 The 5th driest on record since 1954. Mean annual rainfall  (1954‐2015)        425 Amounts and decile rankings for seasonal rainfall at Charlton in 2014 and 2015 measured at the nearby weather station in Donald St., Charlton 
  15. 15. Effect of subsoil manuring on the macro-porosity, saturated hydraulic conductivity, and bulk density in the 10-30 and 30-50 cm deep subsurface layers Site Treatment Macro‐porosity (%) Sat. Hydraulic  Conductivity (cm/hr) Bulk Density (g/cm3) Depth (cm) Depth (cm) Depth (cm) 10‐30 30‐50 10‐30 30‐50 10‐30 30‐50 Ouyen Control 18.9 13.1 1.67 0.84 1.39 1.46 Manured 17.5 15.6 1.67 1.05 1.38 1.41 Significance NS NS NS * NS * P‐value 0.14 0.18 0.49 0.02 0.10 0.02 Hopetoun Control 10.1 ‐ 0.33 ‐ 1.39 ‐ Manured 13.1 ‐ 0.65 0.15 1.33 1.38 Significance * ‐ *** ‐ * ‐ Charlton P‐value Control Manured Significance P‐value 0.013 9.4 12.5 * 0.03 ‐ ‐ ‐ ‐ ‐ 0.001 0.47 0.76 NS 0.10 ‐ ‐ 0.11 ‐ ‐ 0.02 1.39 1.35 * 0.04 ‐ ‐ 1.41 ‐ ‐
  16. 16. Grain/fodder yield obtained from the different Mallee sites where SSM was attempted in 2014 Site 2014 2015 Treatment Crop Gr. Yield (t/ha) Crop Yield (Gr/Fodder) (t/ha) Ouyen SSM Barley 1.6 Wheat 0.86 Control Barley 0.3 Wheat 0.68 Hopetoun SSM Wheat 1.3 Vetch 0.32 Control Wheat 1.72 Vetch 0.34 Charlton SSM Wheat 0.41 Barley 1.17 Control Wheat 0.9 Barley 1.17
  17. 17. NO – SSM will NOT work  in dry country YES – SSM will work in  dry country • Not enough rain to open up  / fill “subsoil bucket”  • Chemical constraints limit SSM • Remote manure sources. • SSM more cost‐effective, farmer‐ friendly; not reliant on manures • Very effective water capture, top‐ soil and subsoil • Chemical constraints not limit SSM
  18. 18. Conclusions: • These trials were conducted in ‘tough’ environments in ‘tough’ times. Below average rainfall at most sites impacted on crop growth and root proliferation. • Inadequate rainfall to fill the bucket and to drive crop growth and root proliferation that will trigger soil change, appeared to result in limited success with SSM in the low tomedium rainfall zones. • Despite the above, changes were still observed at some sites in the physical parameters monitored. • Timing of rainfall appeared to be important to trigger soil-root-microbial interactions: something that could not be expected in sub-optimal rainfall years. • Marginal differences in seasonal crop water use was observed that also resulted in small differences in grain yield. • Some sites showing exceptional results are worthy of being followed up for a few more years to better understand the process of subsoil change in the low to medium rainfall zone. • Chemical constraints may have contributed to inconsistent soil physical change contrary to the expectation from SSM.
  19. 19. CURRENT STATUS OF THE PRACTICE OF SSM • One paddock scale SSM machine in Victoria (1000+ ha) • 4-5 Small scale SSM plot machines in Victoria, Southern NSW SA, WA and Tasmania • .
  20. 20. Thank You

×