Study Site Trials

The SICS selected for trialling in this Study Site are described below:

General Treatment Category Study Site Trials
Tillage and crop rotations  1.Compaction alleviation experiment in no-till system - No-till without alleviation (control); Ploughing; Low disturbance subsoiling; Mycorrhyzal inoculant. Barley in Year 1, Field Beans in Year 2.
 2. Deep-rooting ley grass cultivars in arable rotation – 5 modern deep rooting ley grass cultivars; Mixture of ryegrass and clover (control). Low disturbance sub-soiling and unharvested treatments have been superimposed on the experimental plots.

 General Treatment CategoryStudy Site Trials 

Study Site poster 2018 (download)

 SICS 1 - Compaction alleviation in no-till system

Compaction alleviation experiment 2018 lowres   UK cultivation  

 

Key findings

  • If there is a compaction problem, direct drilling will result in a yield penalty.
  • Earthworm numbers were consistently lower in the two cultivated plots. This supports previous research which found that ploughing reduces earthworm populations.
  • Water stable aggregates were slightly improved by AMF inoculation. Fungi are known to stick aggregates together, so inoculation is improving soil structure, although very moderately.
  • The compaction resulted in higher N2O emissions in the compacted direct drilled plots but CO2 and overall global warming potential was lower.

 

SICS 2 - Deep-rooting ley grass cultivars in arable rotation

 Deep rooting grass ley experimental plots lowres   UK crops  

 

Key findings

  • In unharvested plots, Fojtan had significantly higher root volume at depth than the control and Donata.
  • Less intensive harvesting and lower associated compaction may increase the potential for reduced flood risk through Fojtan root growth.
  • Fojtan and Donata are as productive and palatable to weaned lambs as a conventional ryegrass and clover ley.
  • Cutting and grazing the forage create soil compaction and reduce root growth and the soil’s ability to absorb water.
  • Using Fojtan could contribute to flood risk management if combined with low intensity harvesting.
  • The different grass cultivars resulted in no significant differences in VESS scores, earthworm numbers, soil organic carbon or penetration resistance. Further soil carbon research is now being conducted as a result of this trial.
  • Some of the stakeholders who participated in a final workshop which presented the results of the study were disappointed with the findings of the study, with a suggestion that a longerterm data set would have been more plausible.
  • Regardless, stakeholders remain largely supportive of the SoilCare project.

 

Geographical description

The Allerton Project runs a 333ha mainly arable farm at Loddington in central England. The soils are mainly Hanslope and Denchworth clays overlying Iron stone. The farm is at approximately 150 metres asl and receives approximately 650mm annual rainfall.

Farm map
Case study farm at Loddington, central England.

 

Cropping systems

Cropping intensity
The cropping system is broadly typical of others in the area but adopts an Integrated Farm Management approach with the creation of habitats to encourage beneficial predatory and pollinating insects and other wildlife.

Types of crop
The crop rotation is wheat, rape, wheat, beans or oats but pasture is also present on the farm and grass leys are being brought into the rotation. A three or four-course rotation including wheat, ape and beans or oats is typical of the local area, although a two-course wheat rape rotation has been practiced until recently.

Management of soil, water, nutrients and pests
Over the past decade, there has been a move from plough based to reduced tillage and most recently, a no till approach to crop establishment. Crop residues are returned to the soil. Cover crops are adopted before spring sow crops. Soil are tested for P, K and Mg at least once in each rotation. Some fields mapped for soil type and nutrients. Variable rate N application using Yara’s N Sensor. No irrigation.

Soil improving cropping system and techniques currently used
Reduced tillage or no-till, crop residue returned, cover crops.

Problems that cause yield loss or increased costs
Soil compaction and low organic matter affect rooting capacity, nutrient uptake and soil moisture, as well as runoff and water pollution. Blackgrass (Alopecurus myosuroides), often associated with waterlogged soils, causes severe competition and high herbicide costs.

External drivers and factors

Institutional and political drivers
CAP Greening has increased stages in crop rotation locally, but not at Loddington itself. Sustainable Use of Pesticides Directive influences pesticide use and encourages IPM. Water Framework is a major policy driver influencing soil management, fertiliser application, cropping and pesticide use.

Societal drivers
Environmental criteria such as popular interest in wildlife conservation influence the production of cereals for human consumption (e.g. Conservation Grade, Kelloggs). Conservation of farmland birds and pollinating insects.

Bio-physical drivers
Prolonged heavy rainfall in 2012 affected yields over a two-year period. Increasing intensity of winter storm events, and dry summers could suppress yields in future. Soil management needs to adapt accordingly.