SPRING is an ideal time to assess soils for structural and health issues, but Hutchinsons says, only do so when there is sufficient moisture for an accurate result.

Problems such as compaction can sometimes be misdiagnosed in dry soil, which may appear “tight” or compacted when it actually just needs more moisture, explained technical manager Dick Neale.

He said: "Many growers check soils for compaction straight after harvest before autumn cultivations begin, but when ground is baked dry in July or August, it can appear compacted when it’s not. This often results in unnecessary use of the subsoiler or other deep cultivations which destroy natural structuring.”

Mr Neale said Spring is generally a much better time to inspect soils and identify areas where remedial work may be required later in the season.

He said there are three key reasons for this:

o moisture: A much more accurate assessment of soil texture and porosity can be made when soil is moist, but not saturated. Moist soils will look and feel very different to those that are very dry or saturated. Earthworms also need a moist habitat, so testing moist soils makes it easier to accurately estimate the number and species present

o growing crops: Assessing soils when there is a growing crop in the ground allows rooting to be examined and makes it easier to identify potential issues, such as a compacted layer preventing root penetration. It may also be easier to see which areas of the field need closer inspection if there are visual differences in crop growth that could be due to soil factors

o rising temperatures: Soil temperature has a significant impact on many biological and chemical processes, such as the decomposition of biological material and the rate at which nutrients are made available. As soils warm in the spring, these processes will increase to give a better indication of overall soil health.

Mr Neale said accurately benchmarking the soil’s current status was essential to formulating a plan to improve soil health.

Hutchinsons Healthy Soils service uses in-field and laboratory techniques to analyse the three core components of soil:- physical properties (texture, bulk density, compaction); biological (organic matter, carbon content, earthworms and other “soil life”); chemical (pH, minerals, nutrients and availability to plants).

Mr Neale said all components are heavily interlinked, so a “healthy” soil must balance everything and not concentrate on any area in isolation - getting one aspect out of balance can have serious knock-on implications elsewhere.

The main aspects examined in the Healthy Soils report include a review of historical land use, current cropping, cultivations, drainage, key soil features; visual structural assessment to identify issues such as compaction. Auger test to asses structure, rooting, colour, odour, etc; infiltration test - soaking a column of dyed water into the ground to see how well it permeates through the profile.

It also assesses earthworm populations within the top 20cm; checks pH, organic matter content and nutrient status; bulk density; and cation exchange capacity indicating the soil’s ability to “hold on” to nutrients.