Efficient nutrient use is key to reducing nutrient runoff
Healthy soil and good water management are vital to reducing nutrient runoff. However, at the core of the issue are the nutrients that are added to fields in the first place, mainly phosphorus and nitrogen. They serve a vital purpose when it comes to delivering the nutrients crops need to grow. But there is a risk that what is not taken up by growing crops or stored in the soil will travel beyond the field and contribute to eutrophication.
Adding to the challenge is the fact that large amounts of nutrients are brought into the food system—through the importation of animal feed or the fertilization of crops for animal consumption using mineral fertilizers—and transformed into manure. At the same time, the nutrients in the resulting manure are not efficiently used in crop production since 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 the systematic change that’s needed towards a more circular food system, the decisions made on the farm level remain important. What amount of nutrients are needed, and how should they be applied to ensure efficient uptake and prevent 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 kinds of crops are being grown and even the weather conditions.
Keeping track of nutrient usage and using nutrients more efficiently are essential to successful nutrient management on any farm, benefiting both farmers and nature.