30
DAIry
March 2013
sheds ‘n shelters
Irrigation Issues Dr Tony Daveron
WE CAN DESIGN ANY SIZE TO FIT YOUR REQUIREMENTS
When is clay not clay?
CAlF SHElTER
Dimensions: 3.0 Wide x 4.8 Deep x 2.4 High
MUSTERER’S / DEERSTAlKER’S HUT Dimensions: 5.0 Wide x 11.6 Deep x 2.8 High
BARN 3 Bay Dimensions: 13.5 Wide x 6.0 Deep x 3.6 High Built to your specific requirements
✔ Kitset ✔ Completely built ✔ Built on skids ✔ H4 Radiata Pine ✔ Zinc cladding
✔ Colorsteel ✔ Rugged construction ✔ Made to order
sheds ‘n shelters
5a Cone Street, Rangiora Freephone: 0800 426 639 Phone: (03) 313 4862, Fax: (03) 313 4863 email: newbletimber@xtra.co.nz
We have decided to go underground this time round, but not as you might think. Time to dispel a couple of myths or misnomers about our/your soils.
these clay soils. So the vast majority of the soils as we/you know them are silt loam soils — obvious by the names — you all know them. Like Lismore silt loam, Templeton silt loam, Wakanui silt loam, Chertsey silt loam etc. So just what defines a ‘clay’ soil layer. In Soils 101 the textural triangle is tossed around to provide an understanding of the make-up of different soil types. The triangle is all about lines to the three axes, for example: • Clay ( arrows) yields about 67% clay size particles, 20% silt sized particles and only 13% sand sized particles; and • Loam ( arrows) yields about 20% clay size particles, 40% silt sized particles and 40% sand sized particles.
A B
We literally took you underground for the Field Days — not so far to feel you might be in a mine, but certainly far enough to get ‘down and dirty’ with the soil. The inspiration, if that’s what it is, has come from C the often heard comment or expression about the clay in the sub-soil. You know what I mean — that yellow-brown layer most of you have underlying that dark black topsoil (I hope) and sitting Fig. 1. above the gravels. The largest proportion of the soil on the Canterbury Plains, especially west of SH1 will be ‘Fifty Shades’ of: See fig. 1. A: Top soil – the organic and inorganic matter, water, air & organisms. B: Yellow-brown sub-soil. The “clay” Mostly inorganic and less organic matter, water, air & just a few organisms. C. The gravels – hundreds of metres deep. Inorganic matter, water, & air. The parent material, the building block of the soils on the Canterbury Plains is wind-blown fine sand or silt (loess) or alluvial material (silts, sands and gravels) laid down by braided rivers in flood. Most of the finest material (clays) are held in suspension and travel the furthest in the flood waters from the mountains — so they have ended up at the bottom of the plains — Irwell and Leeston farmers know all about
• Underpasses • Box Culverts • Dairy Lanes
Fig. 2
The soil names are the giveaway for the soil types, whether top soil or sub-soil. Soils like Lismore silt loam, Chertsey silt loam, Wakanui silt loam, Templeton silt loam, Mayfield silt loam are the giveaway — they are silt loams. Take a Lismore silt loam and its make-up is typically: Soil Type Lismore shallow silt loam
Depth, cm
% Stones
% Sand
% Silt
% Clay
0-20
0
5-30
45-80
15-25
20-40
10-15
5-30
33-75
10-22
40-onward
60-75
85-95
0-2
1-4
Not only are these soils lacking in clay size fractions, the clay minerals are not the swelling ‘stick like… to the shovel’ clay types — they are more slippery illites and hydrous micas. Excepting those of you that truly have clay soils (Temuka clay loam, Wakanui clay loam, Tai Tapu clay loam etc.) this yellow brown ‘clay’ layer is far from it — not clay but silt loam or something similar. A long winded story for our inspiration for the Field Days.
Unit for hire with owner operator
Ashburton Contracting Limited
P 03 308 4039 A South Street, Ashburton W www.ashcon.co.nz
High Volume Pumping Unit
Pond Buster Stirrer for Hire
Pond Treatment
Enquire about our IMPACT Effluent pond activator Live bacteria imported from the USA showing incredible results
new SerViCe in YoUr area now!
we have recently purchased a new hi-Spec MUCK SpreaDer from ireland hi-Spec is recognised as the most efficient MUCK SpreaDer on the market. we can spread anything: • Straw from calf-rearing sheds • Stone trap effluent
• feed pads • weeping walls • Scrapings from dairy lanes
• piggeries • pond effluent • Compost
29 Maze Road 12RD, Pleasant Point 7982 P 03 614 8994 | M 027 464 6763 | F 03 614 7547 E contact@effluentpondsystems.co.nz www.effluentpondsystems.co.nz