AS the combines have been out and the harvest largely finished, many will be planning or have planned the cropping programme for the next 12 months.

But one point to ponder is that increases in the value of phosphate over the past few months will alter growing costs. The big question is, by how much?

If you are growing wheat, the removal of P2o5/t with straw carted off is 7kg per tonne. Assuming the P2o5 concentration is 460kg per tonne, this will replace the removal from 65.7 tonne of grain plus straw.

So, for every £10per tonne that phosphate goes up or down, it will alter the growing costs by 15.2p per tonne of grain.

When growing winter barley, rye or triticale, the RB209 removal figure is 8.5kg per tonne, including the straw. So, one tonne of 46% phosphate equals 460 kg per tonne to replace the removal of 54.1 tonnes of grain and straw.

Again, for every £10/t the price goes up or down, this will affect the costs by 18.5p per tonne of grain

Using muriate of potash, which is 60% concentrated, the K2o removal per tonne for winter wheat, winter barley, rye and triticale, including straw, is 10.5kg per tonne. So, every tonne of product will replace the removal of 57.1 tonnes of grain and straw.

Therefore, every £10/t the value of muriate of potash (MoP) goes up or down, it will alter the growing cost by 17.5p per tonne. Therefore, if prices rise by £100, it will alter the cost per tonne of grain by £1.50 to £1.85 and at £200 more, it will affect it by £3-£3.70 per tonne of grain and straw.

Plants will get nutrients from the mother seed, but it is only a very short boost and can be variable as been shown by grain nutrient analysis. If the soil is deficient, then plants grown on that land are also going to be deficient.

Fields can vary differently in terms of soil structure, organic matter, pH and the 13 nutrients that can alter plant growth. What could the limiting factors? We all know that big yields require more nutrients (see Table 1).

Table 1

N efficacy at soil pH 5.5 6.0 6.5 7.0

Nitrogen 77% 89% 95% 100%

Phosphorus 48% 52% 76% 100%

Potassium 77% 100% 100% 100%

The amount of calcium can be a confusing thing, as lime is a source of calcium but many soils can have an acceptable pH, but yet be low in calcium of less than 1600mg/l.

Calcium improves root miles and plant health, but can interfere with phosphorus availability, causing it to be locked-up.

Phosphorus is the key to planting rooting, thus creating biomass nutrient uptake and plant survival. But it only moves slowly in the soil – less 0.2mm/week and so is best to apply with seed via a combine drill.

When you run out of product, or forget to turn on the machine, or the chain on the drill breaks, you can see what the real differences are if this is not applied. A plant never makes up from this early boost of nutrition.

You need to know what is being supplied to your new, seeds/plants. If we assume we sow 400 seed/sq m of good quality seed, with a germination capacity of 90%, then we have 360 viable seeds/sq m.

Fertiliser band applied with the seed at 250kg/ha of product = 25g/sq m, or 25000mg/sq m, or 69.4mg/plant. Precision nutrition like this will optimise farm profit.

But what about the 70/20 option of placing 70% of the P2o5 and 20% of the K2o in with seed. my advice would be to treat the phosphorus with Nutricharge, a product that will optimise the applied P by creating a shield that reduces its ability to lock up other nutrients.

Trials have shown that 30-40% can be made more available for plant uptake and that the subsequent increase in yield far outweighs the added cost of treatment.

Without that, some trials confirmed that less than 8% of the P2o5 applied was taken up by plants, meaning that 92% was locked up.

At the start of spring growth, you can then apply the balance of the P and K, with nitrogen and sulphur. This will make the most of the fact that when the soil temperature starts to build up, plants will generate a new root system creating a demand for all nutrients.

The aim is to build those 'root miles' which will then become the driver in terms of harvest results, plus increases soil organic matter and soil carbon levels – and we all know that this means extra £s!