Fertilizer application in the fall – a review of the guidelines

Autumn is the season not only for harvesting and intensive field work, but also the time to apply fertilizers. In the context of agricultural practices, it is particularly important to comply with the nitrate program, which imposes a special timeframe for the application of such treatments. The program was introduced to reduce potential nitrate contamination of waters from agricultural activities, which is of great importance to protect the environment and public health, but also to ensure high productivity and crop health.

In exceptional circumstances, delayed application of nitrogen fertilizers is allowed. The Ministry of Agriculture has cleared up ambiguities about these exceptions by defining the times when fertilization is acceptable. So when can you fertilize?

Fertilizer application – why are deadlines important?

According to the guidelines of the nitrate program, there are strict deadlines within which the use of nitrogen fertilizers is allowed. These periods are planned in such a way as to synchronize fertilization with the growth cycle of plants, with the time when they are able to assimilate nutrients most effectively, thus minimizing the risk of nitrates leaching into ground and surface water. In addition, adherence to recommended fertilization periods helps avoid unnecessary financial and resource losses, maximizing the benefits of the investment.

However, the Ministry of Agriculture acknowledges that there are exceptional situations in which the subsequent application of fertilizers with nitrogen is permissible and necessary. These circumstances may arise from a variety of factors, such as unforeseen weather conditions, delayed crop cycles or other specific agronomic conditions that justify a deviation from the standard schedule.

The use of fertilizers depends on many factors. When deciding when to apply, it is extremely important to carefully assess weather conditions. Avoid applying before expected rainfall, which can contribute to rapid nitrogen leaching. The farmer should monitor soil conditions, making sure that the soil is sufficiently dry and able to take up fertilizers, and that the temperature and humidity are at the right level to support biological activity and nutrient absorption by plants.

All these steps, taken with due diligence and awareness of current weather conditions and the condition of the crops, are key to achieving maximum efficiency of nitrogen fertilizers, while protecting water resources and caring for the ecological balance.

Fertilizer application – timing

The exact dates of the last possible applications of different types of fertilizers were determined in accordance with the regulations of the nitrate program:

1. For solid manures, which include manure (i.e., a mixture of animal feces, urine and bedding, such as straw, sawdust or bark) and bird manure (i.e., poultry droppings from barnless systems), the cut-off date for application is October 31 on cropland, and November 30 for permanent grassland, perennial crops and permanent crops.
2. The application of mineral fertilizers containing nitrogen and natural fertilizers in liquid form, such as slurry (a mixture of animal feces, urine and water) and manure (that is, liquid leachate from manure, which is essentially digested animal urine) on arable land can be applied until October 20. In some municipalities, this period may be different and fall on October 15 or October 25. For permanent grasslands, perennial crops and permanent crops, the last possible day for applying these fertilizers is October 31.

All of these deadlines have been set to optimize the fertilization process, minimize the risk of environmental pollution, and adapt agricultural practices to the cycles of nature and the needs of plants.

Use of nitrogen-containing fertilizers – extension of deadlines

In exceptional circumstances, subsequent application of fertilizers with nitrogen on arable land is envisaged. However, this option does not include crops under cover or in containers. It is also important to remember that you cannot fertilize when the soil is frozen, flooded or saturated with water, or covered with snow.

Such flexibility in the calendar showing the autumn application of fertilizers is provided for situations such as:

1. harsh weather conditions, which include excessive soil moisture or periods of drought. Under such circumstances, the final date for fertilizer application is postponed until November 30. It is important to note that the nitrate program regulations do not require formal documentation of these situations. It is the farmer who evaluates the weather condition and decides whether to fertilize later.
2. Establishing the crop in autumn, after late-harvested pre-crops, such as sugar beets, corn or vegetables. In these cases, fertilization can be carried out until the end of autumn with the following rules:
   • the maximum dose of nitrogen that can be applied in compound fertilizers must not exceed 30 kg N/ha;
   • it is necessary to precisely document several elements: the date of harvesting the pre-crop, the date of fertilizer application, the type of fertilizers used along with their dosage, and the sowing date of the fall crop.

Such measures are designed to ensure compliance with best agrotechnical and environmental practices, while allowing some flexibility in farm management in the face of unpredictable external factors. Fertilizer application is a must, but following the guidelines will optimize yields while taking care of water.