Page 58 - Simply Vegetables Spring 2022

East Yorkshire District Association
PAUL NEVE FNVS
Our last meeting of the year on 29th November 2021 featured Sarah Owen- Hughes who gave a presentation on The Secrets of Soil. The few who did attend enjoyed a truly professional performance. For those who missed it, we hope to arrange a repeat visit at a later date when perhaps even more people will be tempted to bring along some soil samples for testing.
For those of you with access to Facebook, Sarah produces a monthly podcast at Trowels and Tribulations.
varies between 6.5 and 8.0.
The Soil Association asserts that arable
soils are degrading with some UK soils containing as little as 1-2% of organic matter. Increasing the organic matter content will improve the water-holding capacity of the soil, help to reduce surface run-off/floods, protect against droughts and soil erosion, and stabilise yields of produce.
The Soil Association suggests that
there are seven ways for farmers (and gardeners) to improve their soils. 1 - Increase the amount of plant and animal matter (manures) going back into the soil.
2 - Undertake regular soil analysis and monitoring of soil organic matter levels. Responding positively to health checks has been shown to lead to improved crop yields of up to 15%. 3 - Encourage soil organisms - both those that build up soil and those that release nutrients. 4 - Cover up bare soil with continuous plant cover. Plant roots hold soils together, reducing erosion, and allowing air to penetrate in spaces around roots. Roots also encourage healthier
soil communities through plant-fungal interactions. But benefits spread beyond the farmed area – huge gains can be seen in terms of biodiversity, carbon storage,
About half of soil volume is composed
of solid particles and the rest is pore space filled by roughly half water and half air. Organic matter makes up only about 5% of soil. Understanding your soil composition helps with cultivation timings, application rates for fertilisers and lime, the choice
of plants to grow, the soil improvement choices available as well as developing strategies to help reduce your workload. With reference to the Soil Triangle, soil testing seeks to establish the soil structure and texture ie the relative proportions of sand, silt and clay particles. Sarah also demonstrated a simple test which involved placing a small sample of soil in a jam jar with water, shaking the contents vigorously, waiting for the contents
to settle and then visually
estimating the relative
quantities of the heavier
sand, the medium silt and
the lighter clay particles.
A soil analysis laboratory,
such as our local Beverley
Analytical Laboratories Ltd
at Tickton, would perform
a more accurate version
of this test by kiln drying a
known weight of soil and
then shaking it through a
stack of three different mesh
sieves and weighing the
resulting quantities of sand, silt and clay components retained.
First commenced in the 1970’s, Cranfield University’s Land Information System (LandIS) has provided the basis and repository for holding the digital representation of the soils information collected for England and Wales over
the past 60-70+ years. The soil portal on their website provides you with a range of means to access this information.
Soil pH has an important influence on nutrient availability to growing plants. Extreme alkalinity and acidity will both lock up nutrients and severely impact their take- up by plants. Generally, a neutral pH of 7 is desirable but across the UK the natural pH
flood and drought control, and water quality. Where appropriate use cover crops, green manures and under- sown crops, with the added benefit of improving soil fertility. 5 - Plant more trees, particularly on vulnerable, steep-sided fields or areas of rough grazing. 6 - Reduce soil compaction from machinery and livestock. Soil compaction is a
major problem in the UK – it can lead to increased surface run-off as well as
drought stress, fewer grazing days, poor root growth and reduced yields overall.
7 - Design crop rotations to improve soil health. Carefully design your crop rotations with more crop varieties and longer gaps before going back to the same crop. Put more emphasis on crops that help protect soils and that build soil organic matter such as legume catch crops. Grow crops with different rooting depths to take advantage of the soil’s varying nutrient profile.
The soil food web is an important concept to understand. The variety of life in our soils is amazing. Just one teaspoon of soil contains around 10,000 different species. This variety of life is essential to life on Earth and human prosperity. Whilst
Sarah Owen-Hughes – Soil expert
plants are essential in capturing the energy from the sun, it is the soil life which ensures the burial and breakdown of plant litter
(old leaves and dead plants), releasing that energy for root uptake and transfer back
to the plant. In this way, life in soil is an essential part of the web of life. The major groups of soil organisms include bacteria, fungi, protozoa, nematodes, arthropods and earthworms, though there are many more.
Mycorrhizal fungi, for example, help
to bind the soil, tend to wrap around the roots of plants and can increase the active root surface by up to 700 times, thereby increasing the plants’ ability to take up water and nutrients from the soil. They are also said to assist in the establishment of new roses and apple trees in those sites from which old plants have been removed. Roots also exude waste products and sugars. These feed the mycorrhizae and attract the microbes needed to fix nitrogen, or decompose organic matter. A well- balanced arrangement of soil, air, water and organic matter creates a healthy network
in which soil microbiota can survive. This also enables roots to put their energy into establishing, rather than spiralling around large air pores. Remember that fibrous roots take up water and nutrients, lateral and tap roots are mostly for anchorage.
Sarah’s final tips for us gardeners were mulch, mulch, mulch! Create as much organic matter in your soil as possible and minimise all forms of digging.
Questions from the audience completed the evening. She said that garlic acted as an antiviral and was useful for deterring
Extreme alkalinity and acidity will both lock up nutrients and severely impact their take-up by plants
58 Simply Vegetables