Aspects of carbon and nitrogen cycling in soils of the Bornhöved Lake district. II. Modelling the influence of temperature increase on soil respiration and organic carbon content in arable soils under different managements

摘要: Based on field measurements in two agriculturalecosystems, soil respiration and long-term response ofsoil organic carbon content (SOC) was modelled. Themodel predicts the influence of temperature increaseas well as effects land-use over a period ofthirty years northern German glacial morainelandscape. One fields carried maizemonoculture treated with cattle slurry addition tomineral fertilizer (“maize monoculture”), otherwas managed by crop rotation recieved organicmanure (“crop rotation”). The soils both fieldswere classified cambic Arenosols. soilrespiration measured means theopen dynamic inverted-box method an infrared gasanalyser. mean annual rates were 268 (maizemonoculture) 287 mg CO2 m-2 h-1(crop rotation). Factors controlling respirationwere temperature, moisture, root respirationand input into soil. Q10-valuesof generally higher winterthan summer. This trend is interpreted anadaptive microbial communities.In model novel mathematical approach withvariable Q10-values result oftemperature moisture adjustment proposed. Withthe calibrated SOC werecalculated for simulations aperiod thirty established. Simulationswere based (1) local climatic data, 1961 until1990, (2) regional climate scenario northernGermany average increase 2.1 K.Over present climateconditions, pool under “crop rotation” wasnearly stable due to inputs, whereasabout 16 t C ha-1 lost “maizemonoculture”. Under global warming annualsoil increased SOCdecreased ca. 10 “croprotation” more than 20 under“maize monoculture”. It shown that overestimationof losses prognoses can be avoidedby including Q10-adjustment models.