| Researcher(s) |
Bill Bowden (WMG) Chris Wilkins (WMG) |
|---|---|
| Year(s) | 2015 |
| Contributor | West Midlands Group |
| Trial location(s) |
Dandaragan, WA
|
To demonstrate that, in the right season, ripping affects nitrogen uptake efficiency and availability to crops.
There has been a major response to ripping but little response to nitrogen above and beyond the farmer dressings. The ripping treatment markedly improved crop emergence numbers and timing. The very dry nature of the season after seeding has meant no leaching of nitrogen and therefore no improvement in nitrogen uptake efficiency due to faster root penetration on the ripped plots. Plant counts, estimated biomass levels and yield components are shown in the table of results, above.
There was a marked establishment and growth response to ripping and variability was much more marked on the non-ripped plots than on those which were ripped. Measures of surface soil wettability showed no difference between ripping so the better establishment was probably due to better and more uniform wetting on the rougher, more disturbed, ripped soil.
Ripping gave better early growth but also better finishing conditions as reflected in higher harvest indices and lower screenings. The ripped strip samplings emphasized this point so it seems that the ripping allowed better access to stored sub-soil moisture over the harsh finish to the season. Plant samples from on and off the ripped strips showed no difference in K status.
We sampled on and off visually obvious windrows north of trial (2) on 10 July and south of trial (3) on heavier country on 18th August. Both sites showed unambiguous K deficiency which again was reflected in better grain size and lower screening measures on the K adequate windrow. The sandy site had more severe K deficiency and bigger responses than the loamy site which had a higher soil K status. Both areas would respond to K fertilizer applications.
| Lead research organisation |
West Midlands Group |
|---|---|
| Host research organisation | N/A |
| Trial funding source | GRDC |
| Related program | N/A |
| Acknowledgments |
Thanks to GRDC for funding the project, Charles Roberts for use of the land and to Caz Abbey for technical assistance and dangerous videotaping. |
| Other trial partners | Not specified |
| Crop type | Cereal (Grain): Wheat |
|---|---|
| Treatment type(s) |
|
| Trial type | Experimental |
| Trial design | Blocked |
| Sow rate or Target density | 100kg/ha |
|---|---|
| Sowing machinery |
Ripped with the DAFWA Merredin ripper to 35 cm with modified box boots. The trial was sown by the farmer as a bulk wheat crop across the ripped treatments. |
| Sow date | 25 May 2015 |
| Harvest date | Not specified |
| Plot size | 10m x 3m |
| Plot replication | 4 |
| Fertiliser |
The 4/5 WAS N treatments were applied at 110 kg urea/ha on 1 July and the 8/9 WAS N treatments were applied at 110 kg urea/ha on 29 July. |
| Herbicide |
First knock (pre seeding): 80L Water Rate, 0.4L 2,4-D ester 680, 1.8L Roundup 570 Seeding 25th May: 80L Water Rate, 2L trifluralin 480, 1L Sprayseed 300ml chlorpyrifos Post Seeding: 100L Water Rate, 0.8L 2,4-D ester 680, 10g Logran, 50g Lontrel Post Seeding: 300mL Tebuconazole, Alpha Cyper 125mL, Wetter 1000 0.2% |
SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.
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