TURNING THE LESSONS OF LONG-TERM FIELD TRIALS INTO A 'HUMUS BALANCE' TOOL BOX FOR FARMERS

E. Schulz, M. Körschens, J. Rogasik, I. Merbach
Soil organic matter (SOM) is an important factor for soil fertility and ecosystem services. SOM research studies the soil organic carbon (SOC) structure, turnover, stability and function. As changes in SOC are slow-moving processes, long-term field experiments (LTE) are of particular value. The impact of short- and medium-term management changes on SOC affect primarily the decomposable carbon pool, which represents between 0.2 and 0.7% of SOC under common agronomic conditions in Germany and Central Europe.
The humus balance method presented here predicts the development of soil humus levels by taking into account crop-specific changes within a crop rotation as well as the effects the use of organic fertilisers have on soil humus. The potential of organic fertilisers for replenishing soil humus levels is calculated on the basis of coefficients in relation to aged farmyard manure. Humus balance values define five classes that can be used as a decision and recommendation tool for adapting management strategies that aim at balancing the inputs and losses of the humus balance and to maintain an optimal humus content that is site and land-use specific. Humus balance values that are strongly positive or negative (classes A and D) should be avoided as the agricultural systems they represent are not sustainable. They either impact negatively on soil functions or have a higher potential for nitrogen losses.
Schulz, E., Körschens, M., Rogasik, J. and Merbach, I. (2014). TURNING THE LESSONS OF LONG-TERM FIELD TRIALS INTO A 'HUMUS BALANCE' TOOL BOX FOR FARMERS. Acta Hortic. 1018, 27-38
DOI: 10.17660/ActaHortic.2014.1018.1
https://doi.org/10.17660/ActaHortic.2014.1018.1
long-term experiments, soil organic matter, humus balance method
English

Acta Horticulturae