Catch Crops in Organic Farming Systems without Livestock Husbandry - Simulations with the DAISY model

This paper presents simulations of the soil-plant-atmosphere model DAISY based on an organic crop rotation with incorporation of different catch crops following pea as a leguminous cash crop. Special emphasise was put on the simulation of N-mineralisation/-immobilisation and of soil microbial biomass N. The DAISY model was able to simulate soil mineral N and soil microbial biomass N after soil incorporation of catch crop plant residues to some extend. Several processes need further attention and may be integrated into the DAISY model: (1) soil tillage induced mobilisation of organic material including considerable amounts of organic N, (2) winter killing of sensitive plant species and varieties, (3) decomposition of plant residues at the soil surface as occurring after winter killing, (4) decomposition of easily decomposable plant residues at low temperatures, (5) soil microbial residues as an organic pool temporarily protected against turnover. Furthermore, reliable criteria for the subdivision of green plant residues into an easily decomposable pool and a more recalcitrant pool have to be developed

Global measure of satisfaction with psychosocial work conditions versus measures of specific aspects of psychosocial work conditions in explaining sickness absence

<p>Abstract</p> <p>Background</p> <p>Attempts to identify particular aspects of psychosocial work conditions as predictors of sickness absence remain inconclusive. A global measure has previously been suggested to be an efficient way to measure psychosocial work conditions in questionnaires. This paper investigates whether satisfaction with specific aspects of psychosocial work conditions explains sickness absence beyond its association with a global measure of psychosocial work conditions.</p> <p>Methods</p> <p>The participants were 13,437 employees from 698 public service workplaces in Aarhus County, Denmark. 33 items from a questionnaire fell in groupings around six aspects of psychosocial work conditions: skill discretion, professionalism, management, decision authority, workload and cooperation. A global measure rating satisfaction with psychosocial work conditions on a scale from 0 to 10 was also included in the questionnaire. Individual ratings were aggregated to workplace scores. Analysis of variance and multiple linear regression was used to compare the average number of days of yearly sickness absence with different levels of satisfaction with six aspects of psychosocial work conditions. The covariates included were gender, age, occupation, size of workplace, contact to hospital, civil status and children below 13 living at home.</p> <p>Results</p> <p>Dissatisfaction with each of the six aspects of psychosocial work conditions was associated with an increase in sickness absence. When all aspects were simultaneously included in the model, only skill discretion and professionalism were negatively associated with sickness absence. When a global measure of satisfaction with psychosocial work conditions was also included in the model none of the specific aspects showed a statistically significant association with sickness absence.</p> <p>Conclusion</p> <p>Low global satisfaction with psychosocial work conditions is associated with increased levels of sickness absence. Including specific aspects of psychosocial work conditions in the model does not provide further information regarding the nature of this association.</p