Planting a cereal crop on a livestock farm has many advantages. It provides the option to keep your own grain for feed and you have your own supply of straw (or partial supply).

It provides an opportunity to control weeds and level ground before the area is reseeded again and this can be done straight after harvest into a clean seedbed.

Livestock farmers who have opted to plant cereals in recent years, as a result of poor beef prices, are likely to be tilling long-term ley.

Such ground is likely to be high in soil organic matter and can release a lot of nitrogen to the crop.

Where suitable, reduced tillage can prevent organic matter being ploughed down and minimise carbon being released from the soil.

Cereal crops planted after grass require less nitrogen than continuous cereals, as nitrogen will be available naturally from higher organic matter soils. Crop management can be tricky as a result.

Challenges

Lodging is a real risk in cereals planted after ley due to high soil nitrogen availability.

This nitrogen needs to be accounted for. The soil index system in the nitrates directive should be used.

Table 1 shows where fields fit into the nitrogen index. The longer it is out of grass, the less nitrogen will come from the soil so more nitrogen needs to be applied.

Temporary grass (one to four years of ley) is generally not as fertile and so starts in index 2. Once the nitrogen index is identified, follow the guidelines in Table 2. This states that land out of permanent pasture should not receive more than 40kg N/ha. Higher rates mean you have exceeded the limit while increasing lodging risk.

Applying the right amount of phosphorus (P) and potassium (K) is essential and these should be applied to the seedbed guided by soil test results.

K is a vital nutrient and is often low in grassland, especially where silage has been cut regularly. K helps to build straw strength and prevent lodging and so should be applied in adequate amounts. Slurry or FYM can provide some of the P and K allowance.

Table 3 describes P and K requirement for a 3t/ac spring barley crop. If there is not enough K in your chosen compound, consider applying muriate of potash (50% K) to up the K levels.

Soil pH needs to be around 6.5 for spring barley, so take this into consideration when planting. If soil pH isn’t right, then nutrients won’t be as freely available.

Lodging can cause a host of problems, such as bird damage, slower-ripening crops, a higher risk of sprouting in wet weather, a risk of grain losses, slow harvesting and green straw.

The first step in avoiding this problem is to choose a variety with good straw strength and good resistance to lodging.

Seed rate

Optimum plant population is important. Aim to establish 300 plants per square metre. Calculating seed rate should be based on thousand grain weight (this will be on the seed bag) to help achieve the desired plant count.

A common establishment rate is 85%, but this can be up to 90% if planting in late April. You might need to add about 10% extra, as crows are likely to be active in crops following grass. The equation at the bottom of the page will allow you to calculate seed rate.

After planting, remember to roll, not only to tighten the seedbed but to reduce leather jacket risk.

Growth regulation

Growth regulators provide mixed results in spring barley crops. Applying Terpal at flag leaf emergence can help, but timing is important and can be tricky. Moddus or a PGR containing trinexapac-ethyl might be considered with the first fungicide at early stem extension.