Tillage Update - 31st August 2021
Mark Plunkett, Teagasc Soil and Plant Nutrition Specialist, discusses the importance of correcting soil pH to ensure the efficient use of soil nutrients (N, P K, Mg, S & Ca) and applied nutrients in manures and fertilisers. Also find information about the upcoming National Crops Forum.
Now is a good time to check soil structure and address any soil compaction where present as soils are relatively dry. Over the last week the good weather has been very welcome for completing the cereal harvest and baling straw in ideal conditions.
Check Soil Test Results & Apply Lime
Once fields have been cleared of straw it is an ideal time to check soil test results and identify fields that have a lime requirement. Ground limestone is the most cost effective source of lime for long term soil acidity control. Aim for a soil pH 6.5 to 6.8 for cereal rotations and for sensitive crops in the rotation such as beet/oilseeds/protein crops maintain soil pH 6.8 – 7.0 range. Where soils are low in magnesium (Mg) apply Dolomitic Lime and where soils high in Mg apply calcium lime to correct soil pH.
With rising fertiliser prices projected for 2022 it is critical to optimise soil pH and maintain in the optimum zone. The correct soil pH will increase the availability of soil P, K, Mg & Ca. Maintaining soil pH improves the efficiency of all applied N sources and reduces losses to the environment.
Now is the ideal time over the coming days/weeks to order lime where required and apply to stubble fields either for winter or spring cropping.
Soil Structure Assessment
Now is a good time to take out the spade and assess soil structure. This involves digging a number shallow soil pits (50cm deep) around the field (see figure 1). Take out the top 25 cm (top soil) and assess the shape, size, strength, colour and friability of the soil particles. Examine rooting activity and earthworm numbers in this top zone. This will help classify as good, medium or poor soil quality. It will help identify the presence of soil compaction and how it maybe be dealt with depending on its position. Take out the next 25cm of soil and repeat the same again to assess soil quality and whether a compacted layer is present or not. For example a plough pan is often present from the continuous operation of cultivation equipment at the same depth year after year. Aim to alternate the cultivation depth by using different tillage strategies or equipment. Teagasc and UCD have published “The Soil Structure ABC”. This provides practical guidelines on carrying out the “Double Spade Method” plus visual aids on soil structure assessment. There are a number of short videos available of soil structure assessment; both of these sources of information are available at: www.teagasc.ie/crops/soil-quality.
Figure 1: Assess soil structure in September – “Double Spade Method”
National Crops Forum
The annual National Crops Forum provides an ideal opportunity for farmers to assess the season just gone and also look forward to options for next season. This year due to Covid-19 restrictions, the National Crops Forum will be held over two mornings as a virtual event on Zoom, at 11.30 each morning.
September 9 – Topics: Agronomy & Grain Markets
Update on varieties available for this year with an eye on disease resistance in cereals and the short and medium term markets prospects for grains.
- DAFM - New varieties for 2021
- Phelim Doran, Comex-Mckinnon - Market prospects for Grain in 2021 and 2022
September 16 – Topics: Carbon Farming & Nitrate Leaching
The webinar will look at the carbon cycle and how it can be harnessed to better effect by tillage farmers. It will also look at nitrate losses from tillage and how farmers can mitigate the problem.
- The Carbon cycle: How tillage farmers can maximise the benefits
- Nitrate leaching from tillage soils and solutions for farmers
Listen to this week's episode of the Tillage Edge Podcast below: