Fertilization Economy in Organic Lettuce Production

In a field experiment on a farm registered for organic production, we studied the economic profitability of the application of different organic materials (farmyard manure, FYM; guano, G; soybean meal, S, and forage pea meal, P) in lettuce production. The highest fertility costs per unit of N were found with the P treatment (6.22 € kg N−1), and the lowest with the FYM treatment (0.8 € kg N−1). Due to the application of organic materials, the highest additional profit was made with the FYM treatment (1289 € ha−1), and the lowest with the P treatment (729 € ha−1). If the farm does not have manure at its disposal, with current market prices, the economically most sound application is soybean meal and forage pea meal.