Grower Geoffrey Marshall offered the conference a more personal view
in his presentation summarising his experiences over the past decade.
The immediate past president of the Western Australian No-Tillage Farmers
Association (WANTFA), Mr Marshall grows wheat, barley, lupins, peas and
canola in a 325mm annual rainfall zone on his 2400ha property, Warra Kairan,
at Hyden, 375km east/south-east of Perth.
Over the period of Mr Marshall’s involvement, WANTFA has grown
from a very small membership to number 1400. In the early ‘90s,
wind erosion in the south coast that caused substantial topsoil loss had
been the catalyst for change, he said, noting similarities with Victoria
on that score.
An end to such erosion was one of the most significant changes on his
own property, he said, even during a significant flood in 2000 (200mm
over 36 hours). Now, he said, “rainfall is used where it falls.”
Mr Marshall said he had sold his last sheep seven years ago because it
compromised the no-till system. “Wide rows do work,” he said,
referring to Dr Guy Lafond’s research. For those needing to know
just how wide, Mr Marshall has gradually moved from 15cm to 30cm.
Despite continuous cropping, his soil structure was softer and much easier
to seed into now, he said, with longer sowing and finishing windows. Organic
carbon had doubled over a six-year period.
“There are many exciting changes taking place and more are possible
as the no-till system evolves. If we go back 10 years, we knew so much
less then; people trying to make a start now can gain so much more from
the information that is available.”
Consultant Wayne Smith, of consultancy Agronomic Acumen, presented an
agronomist’s perspective from WA, where no-till began “in
earnest” in 1990, having evolved through minimum tillage during
the previous decade.
The drought had highlighted the benefits of no-tillage. “Despite
WA having had a long run of poor seasons, no-till has gone from strength
to strength because it works in all soils and climates. It is not a fad,”
He estimated that by 2002, no-till had been adopted by about 75 percent
of growers in WA. For those contemplating a switch to no-till, he emphasised,
“it is a system, not just changing the machinery. You will come
unstuck very quickly if that is all you change”.
Among the lessons he shared from WA were tips about weed control. For
example, many herbicides must be applied pre-sowing, he said, and virtually
none should be applied after sowing and pre-emergence.
Diversified rotation was important “otherwise nature will add undesirable
diversity”, he advised. He cautioned against using harrows –
“it makes weeds germinate and herbicides work less” –
and said press wheels were essential.
No-till beginners should use knife points: “Only switch to discs
when you are confident why you are using them and know how to use them.”
“You can seed on less moisture than you think with no-till,”
he said. “You should also seed before rain . . . rather than wait
for wet soil before sowing.”
North, South, West