After seven years of pasture, the legacy of compaction from orcharding remains.
We have ripped the whole area several times to a depth of about 300 – 350mm, but excavations continued to show signs of compaction related drainage issues. The compaction plaguing us is deep, sitting between about 400mm and 500mm.
With the sub-soil reasonably dry after the late pea crop was harvested, we took the opportunity to start addressing the compaction by deep ripping. Using Scott Lawson’s narrow tines, Stu Mawley and staff spent serious hours busting the hard layer. Shear-bolts happily gave way keeping tractor speed to about 1.7 km/h; not fast. While the narrow tines help avoid bringing sub-soil up, we still found some big lumps.
We think some of the hardest lumps are from areas where the old orchard trees were burnt. We’ve seen that the heat from the big fires can “fuse” the soil, but didn’t expect it would remain significant after seven years and a number of cultivations.
Paddocks 1, 5 and 6 were cross ripped twice, first to about 500mm and then to about 650-700mm depth. With the tines at 762mm centres, we were able to rip between the buried drip irrigation laterals (but only parallel with them of course!).
A couple of days after ripping, Stu levelled the paddock with a hoe and roller. The intent was to shift soil to remove the corrugations from orchard rows so the bean harvester can pick up the crop. The second benefit was a traditionally prepared seed bed, ready for Patrick Nicolle to plant beans for McCain Foods.
Many thanks to Te Mata Contractors Stu Mawley and drivers Leroy and Stu Train for tractors and work time. And thanks True Earth Organics Scott and Vicky Lawson for the rippers.