Nährstoffgehalte ökologischer Wirtschaftsdünger

Summary

Manure samples from 194 farms with organic livestock production were analysed for their macro- and micronutrient contents. Guidance values for N, P, K, Mg and S concen¬trations given for conventional systems are within the range of values ¬determined here for organic farms. However, they can only be used for first estimations in fertilization planning, since – as demonstrated by the presented data – nutrient contents may vary over a wide range. This was also the case for the micronutrient concentrations (B, Cu, Zn, Mn, Mo and Se). Fertilization with 1t/ha dry matter of ma¬nure with higher micronutrient concentrations can cover the demand of organically produced crops in nutrient balances. Micronutrients applied with fertilizers or in feed additives are seen to be important external sources in organic farm balances. So besides the influence of pedogenic effects on nutrient feedstuff concentrations, additional nutrient contents in livestock manure of organic farms are highly dependent on the individual farm management. Therefore, nutrients in animal manures need to be determined on farm level for a serious planning of their distribution.