Grain maize requires nutrients in concentrated form, especially in the first stage of mass development, up to the flowering stage. Afterwards, most of the nutrients are only rearranged within the plant or used for water absorption (potassium).
The majority of fertilization is prior to sowing.
The total amount of nutrients required for grain maize can be applied prior to cultivation. The largest need for nutrients is during the first phase of growth, and multiple applications have shown no additional yield. Phosphorus and potash fertilizers are also best applied prior to, or directly at sowing.
With high yield expectations and therefore a correspondingly high N-requirement in maize and also on light soils where there is a risk of N-leaching, split applications are appropriate. One third of the planned amount of nitrogen is applied at the two to four leaf stage. Applying later than this increases the risk of leaf burning and delays ripening. This results in higher grain moisture contents.
Placed (banded) fertilization in the form of an NP fertilizer brings yield benefits, especially on heavy soils, in cold locations and low phosphate soils, as the still small roots can feed directly from the fertilizer belt. Temporary phosphate deficiency in juvenile development can be resolved very well via P-concentrated liquid fertilizer or water-soluble nutrient salts.
Grain corn can be limed prior to maize sowing or in autumn. The maximum quantity of CaO should be 1500kg/ha– preferably in the form of calcium carbonate, so as not to immobilise boron. This maximum quantity should not be exceeded.
Yield parameters of grain maize:
- number of plants/m²
- number of grains on the cob
- thousand grain weight
The yield formation results from an optimal distribution of approximately eight to nine plants per m² and a correspondingly strong healthy cob.