News

Know Your Soil to Drive Health Improvements

Posted on

Assessing the existing physical, chemical and biological properties of soil should be the first step in any plan to improve soil health and the approaching spring is the ideal time to begin the process.

There is much emphasis on “healthy soils” and the techniques to help achieve this, but it is only by benchmarking the soil’s current status that growers can formulate a plan for their situation.

According to Hutchinsons technical manager Dick Neale, moist soils, rising temperatures and active crop growth make spring a good time to conduct an assessment through the Hutchinsons Healthy Soils service, which uses in-field and laboratory techniques to analyse the three core components of soil:

  1. Physical (texture, bulk density, compaction)
  2. Biological (organic matter, carbon content, earthworms and other soil life)
  3. Chemical (pH, minerals, nutrients and availability to plants).

All components are heavily interlinked, so a healthy soil must balance everything and not concentrate on any area in isolation.

Know your soil to improve it

As several speakers told last autumn’s Soils in Practice event at Euston Estate in Suffolk – sponsored by Hutchinsons and several other leading companies – getting a single aspect out of balance can have serious knock-on implications elsewhere.

Soil is a dynamic, living system that relies on specific biological, physical and chemical properties to function properly – fertility being the culmination of these processes, event attendees were told.

 

What a Healthy Soils report offers
The Healthy Soils assessment focusses on the core components of healthy soil, including:

  • A review of historical land use, current cropping, cultivations, drainage, key soil features
  • A Visual Evaluation of Soil Structure (VESS) test - identifies issues such as compaction.
  • An Auger test (to 1m where possible) to asses structure, rooting, colour, odour, etc. Soil is scored accordingly
  • An infiltration test - soaking a column of dyed water into the ground shows how well it can permeate through the profile, highlighting possible issues.
  • An assessment of earthworm populations within the top 20cm.
  • pH, organic matter content and nutrient status (macro and micro).
  • Bulk density (indicator of possible compaction).
  • Cation exchange capacity (CEC) - indicates soil’s ability to “hold on” to nutrients.

 

 

Demonstration Insight
A demonstration of the Healthy Soils assessment at Soils in Practice by Mr Neale highlighted the valuable insights this quick, easy test can provide.

The demo plot was in a field of recently-harvested sugar beet, predominantly on sand/ sandy loam soil over chalk and flint, typical of the Brecklands.

Although the land is well managed, the soil’s natural characteristics combined with intensive root crops in the rotation, create several issues (see Table)

Issue

Cause

Solution

Some surface compaction to around 5” deep. High bulk density (1.4).

Beet harvesting equipment/trailers compacting soil with little natural aggregation.

Sandy soils also tend to have higher bulk density.

Shallow subsoiling to remove wheelings - no deeper than 5”.

Improve soil structure & resilience (see below).

Low CEC (10.9) - poor ability to hold on to nutrients, which are more likely to get washed down the soil profile.

Naturally low clay content.

Apply nutrients “little and often” to a growing crop - avoid trying to build levels in the soil.

Use biology (worms & roots) to help crops access deeper reserves.

Low carbon (1.49%).

Reflection of natural soil structure and intensive crop rotation (beet and potatoes) - high carbon use.

Regular organic matter additions to replace carbon used during the season and improve structure/resilience.

Focus on getting roots in the soil at all times e.g. with a catch crop mix.

Poor water-holding capacity.

Sandy texture.

Build organic matter. Encourage more, deep-working Aneic worms to encourage deeper crop rooting to access more water (some Aneic worms found).

“Improving soil health is all about having a plan and not living from one crop to the next,” notes Hutchinsons business development manager Mike Hales.

“Measure where you’re starting from and develop a clear plan involving the whole system, from cultivations and rotation to cover/ catch crops. It can often be simple changes that make the biggest differences – such as reducing tyre pressures to reduce compaction.”