With air and soil temperatures recovering and soils beginning to dry out, it is time to focus on fertiliser to maximise grass growth and reduce the burden on purchased fodder and concentrates.

Growth rates have been very poor over the past weeks and farmers can expect some compensatory growth to occur as conditions improve.

The Fertiliser Association has issued advice for farmers about how to plan fertiliser programmes to maximise this growth.

All of the advice below is subject to soil test results, nutrient management plan and crop offtake.

Silage

It is imperative that actions are taken not to compromise quality and quantity of next winter’s winter fodder.

Silage ground needs to be closed by the middle of April and cut by the end of May to ensure quality.

Each week late in cutting silage after heading out date will decrease DMD by seven units and delay second cut by two weeks.

1. What level of nitrogen do I need for first-cut silage?

Advice is to use 80 units for permanent pasture and 90 units for reseeds.

Generally allow two units/day from application date to cutting date.

2. Should I delay cutting to increase volume?

For quality silage, harvest crop in late May. Grass will seed/shoot-out between 20 May and 25 May.

3. How will I increase silage made this summer to replenish my reserves?

Aim to increase volume in second and subsequent cuts. Also maximise bales taken from paddocks during the grazing season.

4. Is it too late for slurry on silage ground?

If there is a cover of grass, then slurry application will contaminate the grass – unless it is spread with a trailing shoe or injected.

5. What level of P and K do I need for first cut?

P requirement is 16 units/acre. K requirement is 100 units/acre.

Reduce accordingly for earlier applications of slurry and/or chemical P K applications. If no chemical K or slurry has been applied, reduce K to 60/70 units to avoid luxury uptake of potash.

6. My silage ground has not been grazed. What should I do?

Leave it closed up and fertilise as soon as possible and go for an early harvest date.

7. Do I need sulphur?

Yes, sulphur should be applied up to 20 units/acre for each cut. It will increase grass protein and increase nitrogen efficiency.

Lime

1. Is it too late to apply bulk lime?

On grazing or silage ground, it is now too late to spread lime as it will contaminate the grass. Where pH is an issue, use granulated lime as a short-term solution as soon as possible and consider a bulk ground limestone programme later in the season.

Lime is essential to maximise the returns from fertiliser, as shown in the graph below.

Raising soil pH from 5.5 to 6.5 will increase the efficiency of fertiliser by more than 25%.

Lime will deliver a return on investment of seven to one.

2. Can I spread urea after bulk lime application?

Do not apply urea within three to six months of bulk lime application.

3. Can I spread urea after bulk lime application?

Do not apply urea within three to six months of bulk lime application.

4. Can I spread fertiliser after slurry application?

Maintain a one-week interval between slurry and fertiliser application.

Read more

Talking soil and grass at second Dairylink farm walk

Listen: Only 11% of 200,000 soil samples had optimal soil fertility

Setting up for growth and replenishing stocks