Nitrogen and phosphorus are key nutrients when it comes to nourishing the soil and boosting crop growth. But if they travel beyond the field, through erosion or leaching, they can become the main drivers of eutrophication. Employing measures that monitor the amount, timing, and methods of fertilization is critical to reducing nutrient loss and improving the efficiency of nutrient uptake.
Healthy soil and good water management are vital to reducing nutrient runoff from agriculture. However, at the core of the issue are the nutrients added to fields, mainly phosphorus and nitrogen. These serve a vital purpose when it comes to delivering the nutrients crops need to grow – but what is not taken up by the growing crops or stored in the soil risks travelling beyond the field and contributing to eutrophication.
Adding to the challenge is that large amounts of nutrients are brought into the food system, and transformed into manure – by directly through importing animal feed or by fertilizing crops for animals with mineral fertilizers. At the same time the nutrients in resulting manure are not efficiently used in crop production as farms have become larger and more specialized. In an efficient system nutrients circulate in the system and the risk of runoff is small.
In addition to systematic change to a more circular food system, the decisions on the farm level remain important. What amount of nutrients is needed, and how should it be applied to ensure efficient uptake and avoid over-fertilization? The answer is unique for each field and depends on several factors including soil type, soil nutrient status and the composition of the soil, in addition to what kind of crops are being grown and even the weather conditions.
Keeping track of nutrient use and taking action to be more efficient is the key to successful nutrient management on any farm, benefiting both the farmer and nature.
Balanced fertilization is the key to good plant growth and the efficient use of farm resources. Soil analysis provides insight into what is needed. Fertilization should be planned according to plant needs, yield potential, and the phosphorus status of the soil on the field.
Nutrient balance calculations help keep track of the flow of nutrients on the farm and entail calculating the amount of nutrients in the fertilizers that have been added and taken away through crop uptake. These calculations can help farmers estimate how efficient their nutrient use is during growth seasons. Calculations may vary year to year but over time they provide an overview of fertilization plans so that improvements can be made, decreasing the risk of nutrient runoff and bringing economic benefits through more efficient nutrient use.
An additional tool for ensuring the right amount of fertilization is precision farming. Uniform fertilization can lead to part of the field receiving too much fertilizer while another part gets too little. Precision agriculture equipment and techniques minimize resource use and the risk of over-application. By looking at data from different parts of the field, management activities can be adapted to local conditions.
When fertilizers are applied at the wrong time or in the wrong conditions, the risk of nutrient loss greatly increases. Manure and mineral fertilizers should be applied to the fields during the spring and early summer when growing crops take up nutrients directly. Having adequate storage that allows the manure to be stored during periods when it is not allowed to spread, ass well as corresponding spreading capacity, are important factors that make this possible.
When manure is spread, there is a risk of nitrogen and phosphorous loss via water and air. These emissions contribute to the eutrophication of water bodies, acidification, and can also harm human health. This risk can be minimized through the use of incorporation, injection, or slurry acidification techniques. Manure spreading with incorporation or earthing equipment reduces the risk of nutrient leaching to surface waters by moving nutrients away from the water flowing on the soil surface.
A common challenge the Baltic region is facing is structural changes in agriculture, which have led to larger animal production units and a greater concentration of animal production in certain regions. Large animal production units may lack the sufficient field area required to enable sustainable spreading of manure produced on the farm.
One potential solution is to cooperate with plant production farms. The use of manure or manure-derived fertilizer products on plant production farms can potentially substitute mineral fertilizers. Furthermore, such products can increase and improve the organic matter content in agricultural soils to enable greater carbon storage capacity. If well organized, the benefit can be mutual.
When it comes to transporting manure, cooperation between neighbouring farms is the best alternative since manure’s high water content makes it less profitable for transport over longer distances. Manure processing is one solution that facilitates a more even distribution of manure nutrients. New, innovative solutions are needed that facilitate more effective recycling of nutrients.
Last modified 23/02/21