Saturday, November 28, 2020

Secret is in the soil

December 21, 2017 by  
Filed under Profiles

Peter Cartwright has modified the cropping on the Revesby Estate to improve the soil while tackling blackgrass. Alan Stennett reports.

Soil condition is one of the keys to successful farming, says Peter Cartwright – who has developing a cropping programme to do just that while helping control blackgrass.

“Soil, to me is the key element. Everything we do is aimed at maintain it and building it, and a healthy crop in healthy soil grows away from blackgrass,” explains Peter, who manages the arable cropping on the 1250ha in-hand farm on the Revesby Estate, Lincolnshire.

At one time, the estate was home of 18th century naturalist Sir Joseph Banks. Peter took over the cropping about six years ago – working with owner Gavin Wiggins-Davies and his son, also called Peter – modifying the rotation in the process.

There are currently 450-500ha of winter wheat, 275ha of High Oleic And Low Linolenic (HOLL) oilseed rape; 100ha of beet, 80ha of spring oats, 55ha of spring beans and about 50ha of spring barley this year, drilled after late beet where conditions did not permit establishing wheat.

Land is no longer let out for vining peas and potatoes. Potato cultivation damaged the land and needed irrigation. The reservoir is now a key part of the estate’s carp fishery; and peas proved to be incompatible with the management and varieties in cover crops used before spring cropping.

Little ploughing

“They wanted the cover crops ploughed in, and I wanted to use the plough as little as possible,” says Peter. “The oats in the cover mix caused concerns over a possible allopathy effect on the pea and the extra cultivations caused me to lose blackgrass control.”

Peas were replaced by beans drilled straight into cover crops and removed the requirement for heavy viners to run over the field creating pans. This also retained pulses in the rotation with their Ecological Focus Area benefits, although Peter admits to being irritated by the extra boxes to be ticked following the changes in the EFA requirements.

Sugar beet is still grown, despite the cultivation requirements, but an experiment in growing the crop on a strip-till basis with oats as a cover proved to be unreliable in terms of yield, and is now only used on about 10% of the beet area.

“We got anything from 55t/ha 80t/ha adjusted yield – very up and down and heavily influenced by soil conditions in the spring. But we are carrying on with the small area to continue the learning process while we use the plough on the rest of it.”

A simplified four-year rotation now sees winter wheat followed by rape then wheat again with the fourth year down to a spring crop, usually oats or beans, but with beet on the better land. The spring crop is preceded by a cover crop to improve soil health.


The cover is killed off with :one good dose” of glyphosate before drilling which also helps maintain blackgrass control. Pre-ems and other autumn herbicides are used to control weeds in the wheat, with a robust programme of Centurion Max, AstroCurb and a late Crawler on the OSR.

“If you wait till spring the blackgrass is established and harder to kill, and you hit the crop as well. It’s a belt and braces approach, but it gives us strong crops that can compete as they are growing. It’s expensive but we get the yields and quality to pay for it.”

The cropping also includes an 8ha trial area of spring wheat looking at the effects of very high and low seed rates on blackgrass levels. The low rates returned high levels of the weed, but a rate of 750/m² gave very good control without any loss of yield. The experiment is now being repeated but with soil type taken into consideration as well.

Peter believes the rotation will keep blackgrass manageable. But to get there – and to knock out any future problems – he has a three-year control programme of spring cropping. Initially, he used two consecutive spring wheats drilled with minimum disturbance, followed by a break crop of spring oats or beans, depending on the surviving levels of blackgrass, with a cover crop established before the second and third crops.

Where the break crop is beans, the cover crop isn’t sprayed off until just before the beans emerge. The dying cover then smothers emerging weeds and it no further herbicides are needed, with yields

Clearing crops

Peter has now gone back to spring barley for the two clearing crops because of their better competitiveness with blackgrass and because a new crop dryer has meant that growing wheat and barley no longer causes a bottle-neck during harvest.

“In the past when we were growing spring barley we’d have to break off halfway through the what to go and get the barley when it was at its driest because the dryer was choc-a-block full and we could waste a couple of hours if it then rained, so we grew the spring wheat, so we had nothing but wheat to deal with.

“Now we have a new 50t/hr dryer with an extra 3,000 tonnes of storage addad, so the dryer is no longer a pinch-point and we can go back to the barley, which competes better with the blackgrass in the spring.”

The farm is now moving to a controlled traffic system, with a 10m Horsch Sprinter 10SW drill, a 30m Horsch trailed sprayer and a 35ft combine planned for the 2018 harvest.

All the land has now been scanned for soil quality, organic matter and nutrients, and a selection of fields will be checked against that data each year. Nutrients and other inputs are applied on a variable in-field basis and the effects are being monitored.

“We now know just where we are, and will be able to monitor changes and see how our processes are altering the soil, and how that is affecting blackgrass control,” he concludes.