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To contact one of our “Forage for Profit” team, call the Seed Office on 01769 576232
or Graham Ragg on 07798 583667
or email info@molevalleyfarmers.com.

Soil Testing

The principal objective of soil testing is to make you more money

We are all familiar with providing a balanced ration to maximise animal growth or milk production. This ideally starts with a silage analysis which is then used to source and supply supplementary feeds to ensure the desired yield from our animals. 

We should follow the same principles with our soils to ensure maximum return from our investment in forage crops. This starts with a soil test.

Utilising what you apply

  • Soil tests


Soil testing can increase your profit by identifying acidic fields where low pH results in inefficient fertilizer use and limits your yields. The graph below shows the dramatic effect of pH on the major nutrients’ availability.

  • Reducing inputs


The test may reveal that your soils have adequate levels of some nutrients and that you can reach optimum yields with less fertiliser, enabling you to reduce, or not apply, those nutrients in surplus.

  • Reaching the crop’s potential


Soil testing can help by identifying fields that have low fertility and need more fertiliser than you normally apply. Your potential yield increase can far outweigh the cost of the fertiliser you should apply. Nitrogen recommendations for growing crops assume that ALL other macro nutrients are available at levels which can support the crops potential. For example if there is only 80% of the phosphate needed to reach potential yield, under your current fertiliser regime you could be wasting 20% of your Nitrogen.

The element which is in shortest supply (in this case K) limits the yield

  • Assess the nutrients you apply


By responding to the analysis and applying more of any deficient nutrients and none of any in surplus, you may keep your input costs about the same, but dramatically increase your fertiliser efficiency and yield. Considering the four points above, the chance of successfully fertilising a crop without a soil test are at best 25%.

Sampling

As with most things the results are only as good as the sample. So it is imperative that these are collected to ensure a representative result for the field and the crop being grown. A guide on how to take soil samples is available from Mole Valley Forage Services. Fields should be tested on a five year basis.

Full vs basic test

Historically we have focused on pH, P and K analysis, which are undoubtedly vital to ensure good crop growth. This was mainly due to a cost and inaccurate results of the other major elements, and to a certain extent a lack of research evidence as to their effect on plant growth. Our understanding of plant nutrient interactions has increased and cost is no longer prohibitive. To get the most from your soil test, it is advisable for it to look at:

  • All major nutrients
  • Trace elements
  • Organic matter content
  • Cation exchange capacity

Recommendations

When a soil test comes back, the minimum that should be done is to change/adjust management practice to allow for the results. It is advisable to use a F.A.C.T.S qualified specialist as some low nutrient availabilities can be due to antagonisms, and applications of lacking nutrients may not be effective. See page 12 for our offers on soil testing and grass seeds.

For more information on soil tests and advice on fertiliser choice, timings and recommendations please contact your local Forage specialist or the fertiliser helpline on 0845 603 1210.

Analysis Result Guideline Interpretation Comments
pH 5.2 6.5 Low Reduction in availability of Major Nutrients
Phosphorous (ppm) 9 26 Very low (Index 0.9)
Potasium (ppm) 147 121 Normal (Index 2.2)
Calcium (ppm) 1783 2000 Slightly low Consider treatment to maximise calcium and major nutrient availability
Magnesium (ppm) 205 176 Normal (Index 4.3)
Sulphur (ppm) 7 10 Low Consider treatment for optimum grass growth
Sodium (ppm) 37 90 Very low PRIORITY FOR LIVESTOCK HEALTH
Zinc (ppm) 5.5 7.0 Slightly low PRIORITY FOR LIVESTOCK HEALTH
Manganese (ppm) 26.0 5.0 Normal Adequate level
Molybdenum (ppm) 0.04 <0.50 Normal No problems anticipated
Copper (ppm) 1.7 8 Very low PRIORITY FOR LIVESTOCK HEALTH
Boron (ppm) 1.26 0.5 Normal Adequate level
Cobalt (ppm) 2.2 1.5 Normal Adequate level
Iodine (ppm) 0.6 1.5 Very low PRIORITY FOR LIVESTOCK HEALTH
Iron (ppm) 1221 50 Normal Adequate level
CEC (meq/100g) 18.4 15.0 Normal Cation Exchange Capacity indicates a soil with a good nutrient holding ability
Organic Matter (%) 8.9 3.0 High Humose soil, Above 16% peaty soil

 



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