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| Case Study 4 - Progressive adoption of
reduced cultivation |
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Location |
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Wiltshire |
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Size, average field size and spread |
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352ha; 12ha; 6.4km |
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Soils and landscape |
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Predominantly flat land, largely on Gault Clay which
here produces dense, slowly permeable clayey soils (Denchworth association),
which suffer seasonal surface waterlogging. A small part of the farm has
moderately permeable clay loam soils over chalky gravel, which is variably
affected by groundwater (Block association). The farm has a few steep banks. |
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Cropping |
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200ha winter wheat (1st and 2nd wheats), 40ha winter
oilseed rape and 64ha of other break crops. |
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Workforce |
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The farm is managed by family labour - farmer and
father (part-time) plus extra help at harvest. |
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Equipment and cultivation machinery |
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Simba 2B Discs 3m; Simba ‘Double-Disc’
press; Paraplow; Cambridge rolls; Krause 3m No-Till drill; 150hp JCB Fastrac
2150 (new 2001); 110 hp Massey Ferguson 3080 (11 years old); 95hp Case 995
(8 years old); SprayCoup s/p Sprayer; Case 2188 Axial-Flow Combine. |
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Cultivation Policy |
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All crops are direct drilled
following an inter-crop glyphosate spray, with the exception of oilseed
rape, which is direct-drilled into chopped wheat straw and some beans which
are broadcast and ploughed down. First wheats have a single pass of disc
and press, second wheats have an additional disc and press prior to spraying.
Sub-soiling is only done when necessary. |
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Costings and Work rates |
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Operation |
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Output (ha/hr) |
Cost (£/ha) |
Time taken (min/ha) |
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Discing & Pressing |
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2.8 |
25.0 |
22 |
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Rolling |
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4.0 |
9.0 |
15 |
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Direct-Drilling |
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2.8 |
5.0 |
22 |
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Sub-soiling |
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1.4 |
40.0 |
43 |
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Spraying |
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16 |
7.5 |
3.75 |
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Discussion |
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Decision to change |
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To help control herbicide resistant blackgrass and
slugs. Surface cultivation and stale
seedbeds are additional tools for its control. Ploughing had not controlled
black grass but
simply rotated seeds annually and accentuated the problem. |
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How |
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The original plough, power harrow combi-drill system
was progressively changed to a
reduced cultivation system over 3 to 4 years. First the Amazone RPD drill
was given disc
coulters to allow it to work in trashy seedbeds. The old lightweight discs
were replaced by
Simba 2B discs and the single press by a heavier double press. This enabled
a move away
from ploughing. The following year the combine harvester was changed to
a second hand
Case Axial Flow to improve the ability to chop and spread straw/chaff and
aid incorporation.
In the third year the drill was changed to a 3m Krause triple disc drill
capable of much higher
work rates and able to direct-drill rape crops into undisturbed stubbles.
Otherwise the stubbles are disced and pressed to create a stale seedbed,
usually in one pass, but two passes are used when there is surface trash,
and are left as long as possible to allow termination before spraying and
drilling. |
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Benefits |
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The strategy has controlled black grass; the fine/firm
seedbed has improved crop emergence
and reduced slug activity; the system has created much local farmer interest
and led to some
contract work which has helped fund the purchase of new machinery. A dramatic
reduction in
establishment costs and an increase in work rate has been achieved. |
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Problems |
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Biggest problem is time to get a satisfactory stale
seedbed. This may delay drilling of winter wheat until October- not ideal
on the heavier land. Drilling output had to be increased in the reduced
operational window. The Amazone combination, although effective, was slow
(sometimes 4.8km/hr). The Krause drill does not leave such a good finish
but at 12km/hr can cover far more land per day. |
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Solutions Found |
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Delayed drilling can create problems in wet autumns,
especially where stale seedbeds had been insufficiently re-consolidated.
The Simba double disc press leaves a soil surface that will
dry out unless conditions are intolerably wet. |
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SMI COMMENT |
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Progressive adoption; the
scheme has evolved in a sensible way. The time of 18min/ha is good for modest
size equipment. There is ample time for timely crop establishment. A recent
change to a Horsch cultivator drill has allowed the farmer to expand his
operations to a further 280ha. |
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Soil Group |
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Type of Year |
M.W.D.s' |
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M.W.D.s' |
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Denchworth |
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Normal
Wet |
40
17 |
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5
0 |
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Block |
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Normal
Wet |
90
67 |
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15
0 |
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