Farm Ireland
Independent.ie

Friday 23 June 2017

Carry out sampling to evaluate quality of your soils

Tillage

Gerry Bird

The final round of field inspections has been carried out, marking the end of a successful year on the tillage front. The good spell of weather encouraged some of my growers to keep drilling winter wheat into late November.

These crops are struggling against the elements, slugs and crows. Slug damage on crops is severe in certain fields, due to the seedbed quality and delayed emergence. The application of slug pellets is vital and repeat applications may be required to reduce the slug populations below critical levels.

Crows are active particularly on emerging crops and where the plant loss is high, control methods should be employed. Winter barley is very forward, with trace levels of mildew and net blotch evident, while the recent frost has also had an impact on crop colour. Oilseed rape crops are advanced and waiting for the inevitable pigeon onslaught.

Field visits at this time of the year are mainly concerned with observations on crop emergence, weed and pest levels and soil structure conditions. Soil sampling is a task which also should be carried out at this time of the year when soil activity is relatively stable.

There is a requirement to sample fields in continuous tillage for organic matter levels, and if the levels are below 3.4pc a remedial action plan has to be undertaken. Walking fields at this time of the year allows observations on soil drainage and structure.

The recent rain has resulted in saturated soils in many fields, and investigation now as to why the problem occurs will help in future crop management. Drainage of the excess water can be slowed down by soil type, compaction, poor structure and blocked drains.

Rental

The structure of the short- term land rental system is not conducive to drain maintenance. I have rarely observed drain cleaning or maintenance on rented land despite the fact that water management is critical to profitable crop production.

Waterlogging can have a serious impact on crop emergence, especially in a situation where the soil is saturated shortly after sowing. Basically, the soil is starved of oxygen.

There are many consequences of a saturated soil for the overall structure, nutrient availability and biological activity of the field. The impact on the crop depends on many factors such as crop type and stage, soil type and structure, extent and length of the waterlogged period and climatic conditions (soil temperature).

Saturated soils in early autumn when soil temperatures are conducive to growth can result in poor root development and weak plants. The lack of oxygen around the root zone results in conditions suitable for anaerobic bacteria and fungi to operate, which create toxins and then damage the roots. A wet soil is also a cold soil. It takes a lot of heat energy to warm up the soil, which slows down root development.

Waterlogged soils in mid-winter have a minimal impact on crops. The lower temperatures slow the growth of both the crop and damaging bacteria and fungi. However, saturated soils in early spring will result in poor crop growth due to cold soil temperatures and reduced nutrient uptake.

Wet areas result in weaker crops, inefficient fertiliser uptake, increased grass, weed and scutch levels, reduced pH and ongoing soil structure issues. Information gathered now will help the formulation of plans on future soil management.

Field drainage activity has to take account of the measures outlined in the laws governing the impact of drainage activities on environmental features.

Best wishes for a happy Christmas and a prosperous new year.

Gerry Bird is a crop consultant and member of the ITCA. Email: gjbird@eircom.net

Indo Farming