Growing Grass crop nutrition advice

Everything you need to know about grass or grass-clover mixture fertilisation, best practice, suitable products, field trials and more.

Crop nutrition advice for growing grass

  • Grass performs best in soils with a pH at minimum level of 4,8-5,0.

  • Grass-clover performs best in soils with a pH at minimum level of 5,2- 5,5.

  • Every single cut needs to be fertilised with organic and/or mineral fertiliser.

  • It is recommended that a mineral sulphur application is used for every cut

  • Fertilisation with sodium, copper, cobalt and selenium is needed for the health of the animals when soil levels are low.

Grass field with Polysulphate applied
Grass field after cutting

Nutrient requirements

Nutrient requirements in kg/ha for dry matter yield of 12 ton/ha  

NPKMgOSONa2O
Kg/haKg/haKg/haKg/haKg/haKg/ha
Grass (silage)
(Reference section 3 RB209)
25050100125050

Recommendation of the different nutrients depends on soil fertility. 

Dynamic of nutrient uptake of a silage crop

The nutrients are distributed over several cuts. 

Nitrogen: The first cut gets the highest application and after that each cut gets a lower application.

Phosphate, potassium, magnesium and sodium: divide the required nutrients equally over the different cuts. 

Sulphur: 50 kg/ha of mineral SO3 to be given before the first cut. 50 kg/ha for every cut after that.  

Role of nutrients

Key parameterNP2O5K2OMgOSO3Na2
Dry matter yield+++++
Protein content +++++
Palatability of grass +++
Digestibility of grass +++++

Grass trials

Organic Grass and Clover
Winterswijk, The Netherlands, 2021

21.4

Crude Protein Increase

Q&A

Here are some frequently asked questions we received from farmers regarding grass.

  • Grass cannot uptake sulphur in organic form. Organic sulphur from organic matter or slurry first has to mineralise in the soil. This process starts with higher soil- temperature (>7°C). So for the first cut a mineral sulphur application is needed for all soil types.

  • This depends on the amount of slurry. In many countries the amount of slurry is too low to reach the yearly potassium uptake of grass (36 kg/ha/ton dry matter).

  • In many countries it advised to use mineral sulphur-fertilisers with an organic certificate like Polysulphate, Gypsum and Kieserite.

  • Our usual recommendation is 150 kg/ha SO3 on clay soil; 100 kg/ha on peat soil and 200 kg/ha on a sandy soil. To be given only for the first cut.

  • Grass does not need any micro-nutrients for yield. Micro-nutrients like copper, selenium and cobalt, and also the macro-nutrient sodium, are needed for the health of the animals.