Importance of good soil structure highlighted at open day

The results of a soil test must underpin all soil fertility management decisions, according to Grassland Agro’s Noel McCarey.

Speaking at an Open Day on the McCollum family farm near Coleraine recently, he said that a very small outlay will actually save farmers literally thousands over the course of a growing season.

“Assessing soil structure is also crucially important. Most fields in Northern Ireland have suffered in the wake of the recent wet summers and the increasing weight of harvesting and tillage machinery. Soil compression and the development of quite shallow plough pans can result in crops not developing a deep enough root structure. Poorer drainage can also result in these circumstances.

“One way of getting a firm handle on these matter is to go out into a field and dig down a few inches with a spade. Using a soil aerator in the autumn is one way of ameliorating the problems caused by soil compaction. The spade test will help farmers assess how deep they have to go down, when it comes to improving the drainage characteristics of the soil.”

Grassland Agro’s Campbell Hume suggested that farmers should also have their slurry and farm yard manures analysed.

“There can be a wide variation in the fertiliser value of animal slurries,” he said. “Going on text book values can, sometimes, be quite inaccurate. Making best use of animal manures is crucially important. And in this regard it is imperative for an aerobic breakdown of these products to be achieved, once they have been spread. In this way they will add significantly to the humus and organic fraction of soils while, at the same time, maximising the availability of the plant nutrients they contain.

“However, if slurries are spread on waterlogged soils with an inherently poor structure, an anaerobic breakdown process will ensue. This is a very acidifying process and can be quite counterproductive from a plant growth perspective.”