smi.org.uk

Topical Comment


Case Study 9 - Planned change from plough to reduced cultivation system

	Location		Cambridgeshire

	Size, average field size and spread		1483ha

	Soils and landscape		The land is dominated by deep stoneless silt loam soils (Wisbech association) where groundwater levels are controlled by ditches and pumps. Towards the west, similar but clayey soils predominate (Wallasea association) and occasionally these overlie peat at depth (Dowels association). Locally, deep permeable sandy soils occur with peaty topsoils (Isleham association).

	Cropping		Crops include winter wheat (646 ha), winter beans (191ha), spring beans (117ha), winter rape (67ha), Spring rape (69ha), sugar beet (110ha), potatoes (72ha), combinable peas (41ha), and set-aside (171ha). The farm usually grows vegetable crops, but this enterprise is being put on hold. Historically all the land was under the plough but the need to increase work rates with fewer staff has meant that reduced cultivation is now the preferred option for most of the combinable crops established in autumn.

	Workforce		Workforce currently under change.

	Equipment and cultivation machinery		The farm is in the process of re-equipping following the retirement of 2 CAT Challengers who have done most of the work on the estate when the plough was the primary tool. The proposed equipment is a single, new CAT Challenger or CASE Quadtrack which would be used for late summer/ autumn subsoiling operations and high-speed spring cultivations. This would also do winter ploughing in front of potatoes, sugar beet and other spring crops. A 270hp tractor will complete the draft equipment, capable of subsoiling, ploughing and pulling the triple bed former in front of potatoes. However its main use would be to pull a set of discs post-harvest for high speed crop establishment with a 6m Vaderstad Rapide drill.


	Cultivation Policy
	The farm is divided into two rotations based on the ability of the land to be irrigated. The rotation on this land is wheat/potatoes/peas/wheat/sugar beet/wheat/brassicas/brassicas. The non-irrigated land operates a rotation of wheat/rape/wheat/beans or set-aside.

	Crop sequence
	Operation			Output (ha/hr)	Time taken (min/ha)

	Plough			1.2	50

	Mono			1.2	50

	Discs			3.0	20

	Vaderstad Drill			3.2	20

	Rolls			6.0	10

	Triple bed former			0.5	120

	Discussion

	Decision to change		A re-appraisal was initiated because the Challengers were reaching the end of their life, the transfer of a Vaderstad drill from a sister farm and the suspension of vegetable production and low prices.

	How		A move from ploughing to reduced cultivations in all crops where this can practically be achieved. Rape land going to wheat is now disced and pressed (once or twice depending on conditions), with tramlines subsoiled out if required. The stale seedbeds are sprayed off pre-drilling and direct- drilled with the Vaderstad Rapide. On wheat land going to rape the straw is baled off for sale to the local power station, with the rapeseed either broadcast with the pneumatic fertiliser spreader or direct-drilled with the Vaderstad Rapide. Wheat land going to beans is left post-harvest as a stubble with the beans broadcast on the surface and ploughed down to establish. Wheat going to second wheat is mostly ploughed to reduce trash borne diseases but increasingly non-inversion cultivation is used in conjunction with seed treatments. Root crop and spring sown break cropland is still ploughed.

	Benefits		Increased output, timelier establishment, lower costs.

	Problems		Vegetable crops leave much standing crop debris in the field and since many of these crops are harvested during the winter months the only effective method of disposal is the plough. Likewise trash from the sugar beet crop along with soil damage from the harvesting process means that intensive cultivations are required to restore soil structure.

	Solutions Found		Still building on experience before reducing the ploughed area.

	SMI COMMENT

	The move away from brassicas and vining peas means that this farm can practice reduced cultivations across a wider hactarage, justifying the investment in new equipment. Ploughing will still need to be done for beet and potatoes, but at less than 200ha, contractors could do that in future. This system requires twice the machinery working days for crop establishment than is available in a normal year, therefore there is a need to increase the work rate especially for autumn establishment.

	Soil Group		Type of Year	M.W.D.s'			M.W.D.s'

	Hanslope		Normal Wet	86 65			28 7
	Melford		Normal Wet	122 105			43 22

	Man days required for use of plough on all autumn cultivations

	520ha


		Copyright UK Soil Management Initiative Limited 2005 - Developed by Internet Solutions from ADAS