Fertilizer use in Swedish agriculture was limited until the 1950s, with farmers relying on integrated crop and livestock systems that maintained a biological balance. Crop rotation with legumes provided nitrogen, but low input of purchased fertilizers restricted production. With cheap fossil energy, fertilizer application increased until the late 1970s, leading to specialization and breaking the nutrient cycle between livestock and crop production. Animal-intensive farms had excess manure, while the availability of cheap fertilizers reduced farmers’ incentives to utilize manure efficiently. The result was surplus nitrogen and phosphorus application, contributing to eutrophication in water.
At the start of the 21st century, Sweden introduced environmental quality objectives requiring agriculture to reduce nitrogen and phosphorus losses. Financial support enabled action, and farmers actively engaged in achieving these goals. Representatives of farmers, advisors and authorities joined forces to launch a campaign of introducing free advisory services emphasizing individual farm visits and nutrient balance calculations. More than 18,000 nutrient balances were conducted over 15 years. Evaluations showed that combining balance calculations with advisory services improved nutrient management, leading to declining nitrogen and phosphorus losses.
The free advisory service attracted many farmers, offering a whole-farm perspective on nutrient handling. Farmers with both crop and livestock production found this particularly valuable for achieving profitable yields. Most farmers reported savings in costs and workload as an effect of improved nutrient management. Future farmers will still have incentives to optimize nutrient use while working toward sustainability. Those already convinced will continue seeking advice, while others, previously without access to advisory services, benefit from the free support as a starting point.
Nutrient imbalances can create conflicts between short-term animal health and long-term soil fertility. Knowing the nutrient content of manure is crucial for planning crop fertilization on a farm with livestock production. Accurate calculations, based on farm-specific data, help farmers optimize nutrient use. Nutrient balance calculations typically rely on data from purchased and sold products at the farm-gate. Farmers with livestock production should benefit from account for nutrients in feed, manure, and livestock production as nutrient amounts circulating within farm are substantial. With advisory support and access to nutrient values for currently used feedstuffs the farmer receives an optimized feeding plan and a calculation of the amount of plant nutrients in manure coming out of the stable. That would prevent excess nitrogen and phosphorus in animal diets, which would otherwise accumulate in manure and increase environmental risks.
Manure management is critical for maximizing its fertilizer value. Proper storage prevents phosphorus losses, while nitrogen losses, primarily through ammonia volatilization, can be minimized with best management practices. Crop field trials confirm that phosphorus in manure is as effective to crops as synthetic fertilizers, meaning livestock farmers often have sufficient phosphorus without additional purchases. However, nitrogen is the key factor for yield, and farmers often overapply manure and fertilizers, increasing nitrogen losses. Farmers receiving advise concerning nitrogen balance calculations, ammonia loss assessments, and best practices for manure application improve the nitrogen use efficiency. New knowledge about best manure management is transferred to the farmer through free courses and study visits. Individual advisory services provide tailored guidance.
The farmer knows that effective manure management offers multiple benefits: improved animal housing climate, cleaner livestock, reduced odor, and lower reliance on synthetic fertilizers. Farmers recognize its importance for sustainable food production and environmental protection. However, motivations vary—some seek cost savings, others aim to prevent stricter regulations, meet consumer expectations, or ensure their farm’s long-term viability. Addressing these diverse incentives is key to engaging farmers in achieving environmental goals.
Eva Salomon
Associate Professor, Swedish Knowledge Center for Animal Husbandry, RISE
Sweden
