Planning for early grass on drystock farms
The View from Northern Ireland: In the latest management notes prepared by staff from the College of Agriculture, Food and Rural Enterprise (CAFRE) key topical issues including early grass, soil fertility and slurry management on drystock farms.
Planning for early grass
Nitrogen fertiliser can be applied from 1 February when ground conditions are suitable. Ideally, younger swards on dry south facing sheltered fields with some grass cover should be selected as they will respond best to early fertiliser. Sow approximately 40 kg N per hectare or 30 units per acre.
If soils are low in lime (low pH) and/or are lacking in phosphate or potash, there is always a poorer response to nitrogen fertiliser application. Now is a good time to carry out soil analysis, before any phosphate or potash has been applied. Soil sample every four years and up to four hectares can be included per sample. The sample needs to made up of soil of a similar type and from a similar management system. At a cost of 62p per hectare per year, it represents good value for money.
Organic manures are a valuable source of nutrients. A dressing of 34 cubic metres (7,500 gallons) per hectare of beef cattle slurry typically provides 25 kg N, 20 kg P and 80 kg K per hectare. Slurry can be applied from 1 February, when weather and ground conditions are suitable.
Poultry litter is a very valuable source of N, P and K. One tonne of broiler litter can supply 10 kg of available nitrogen, 25 kg of available phosphate and 23 kg of potash.
It is important to know how much you are spreading per hectare, therefore weigh sample spreader loads to check spreading rates. Soil sampling is essential and use results to target the application of poultry litter. Oversupply of poultry litter onto land with high P and K soil levels is wasteful and will result in grass with high nitrate levels and very high soil phosphate and potash levels. High potash levels will reduce the uptake of magnesium into the grass plants, potentially causing magnesium deficiency in breeding livestock.
Remember farms with a poultry enterprise must stay below the 170 kg per hectare of total nitrogen from organic manures produced on the farm in any year. Beef and sheep farms with a poultry enterprise need to check their nitrogen levels per hectare from their farm organic manures to ensure they are within the limit. You may need to make arrangements to export organic manures to other farms that have the scope to take it. Both need to keep accurate records of the quantities and dates of movement.