Juicy grass needs nutrients

With grass being cut or grazed, high amounts of nutrients are exported from the field and need to be replaced.

Nutrient needs of grassland are highly variable, depending on soil and weather conditions, plant species and farming strategies. Improving earnings requires fully understanding these nutrient needs.

Example for average nutrient needs under different grassland faming schemes in Southern Germany.

Macronutrients

Nutrient extractions from grassland depend on many factors; especially yield expectations but also grazing intensity and animal rejections. This table gives an overview of main nutrient extractions from mowed grassland as a function of yield.

A healthy ratio of nutrients is important for animals. If certain ratios are exceeded, animals may suffer from malnutrition.

Animal health depends on sufficient nutrient supply, but also on their balanced availability. Nutrition imbalance may negatively impact health. The thresholds shown in this table are considered critical.

Micronutrients

A balanced crop nutrition strategy is essential for highest yields. The most important micronutrients on grassland are copper, manganese and zinc. Other micronutrients are required by grazing animals and include sodium, copper and zinc. These are required in higher levels by animals than they are required for grass growth, as shown in this table.

Micronutrient Uptake (g/ha/yr) Intensively grazed dairy Extensively grazed beef
Fe 3000 150
Mn 1000 60
Zn 6000 45
Cu 150 15
B 150 9
Mo 40 0.3
Se 10 0.15
Co 2.5 0.15