Finishing touches for spring sown crops
Key micronutrients will finish your spring sown crop with a flourish.
Boron for brassicas
Boron must go on at sowing or as close to sowing as possible to avoid brown heart in brassica crops and fodder beet. Boron cannot be applied to alleviate brown heart symptoms once cells collapse, so it is best to avoid the problem than try to correct it.
To determine your boron requirements, a boron soil test greater than 1.1ppm is your goal. NutriMax Boron 15% (granular boron which can be easily added to a mix) or Cropzeal Boron Boost (a compound fertiliser combining readily available boron with nitrogen and phosphorus) are good options to apply with starter fertiliser.
Other crop needs
Other spring sown fodder, silage or arable crops typically do not need other micronutrients unless there are localised underlying deficiencies or if the soil pH is greater than 6.5, which can affect availability of some micronutrients. Maize grown on peat soils sometimes show signs of micronutrient deficiency.
Leaf (herbage) tests are the best way to see if micronutrients are required, as there is no strong relationship between soil levels and what appears in the plant. Timing is important. Test too early and the crop may not have had time to take up the available micronutrients. Too late and you may not have enough time left in the growing season to address any deficiency you find and improve yield. For spring sown crops like brassicas and maize, testing in December/January is generally ideal. For spring sown cereals, the best time to test is during mid to late tillering.
It is very important that you compare your leaf/herbage test values with a deficiency level to identify whether or not you will get a yield response to your micronutrient application.
If you have been advised to apply micronutrients, check that you’re not wasting your time and money, by asking these questions.
- Has a leaf test been taken?
- Was it taken at the appropriate time?
- What are the deficiency levels for the micronutrients in the crop?
- Is there enough time for a micronutrient application to have an impact on yield?
- Was the soil pH high?
- Is there a history of past micronutrient deficiencies?
Aside from boron, micronutrients are often applied in solution to leaves. Foliar application applies micronutrients very evenly, ensuring all parts of the crop benefit, allows for rapid uptake to correct any deficiency quickly and it also avoids levels of other nutrients in the soil or pH from interfering with micronutrient uptake. Use products specifically designed for foliar application as they contain additives to help the product stick to leaves and deliver the micronutrient effectively. If fungal disease is a risk, a fungicide can be combined with the micronutrient spray to tick off two jobs in one hit.
Apply foliar sprays in the correct conditions to avoid product loss and reduce the risk of leaf damage: not too much sun (early morning is good), no rain to wash the application off leaves and no wind to evaporate the solution.
For more information talk to your Ballance Nutrient Specialist or click here to find out more about Cropzeal Boron Boost.