Hvad forstås ved begrebet jordens frugtbarhed

Jordens frugtbarhed afhænger af et komplekst samspil mellem naturgivne og menneskeskabte forhold. En karakterisering af jordens frugtbarhed kræver bestemmelse af flere nøgleparametres udvikling over tid. Begrebet jordens frugtbarhed kan meningsfyldt defineres som jordens evne til vedvarende at understøtte en landbrugsmæssig planteproduktion, der er forsvarlig med hensyn til omfang, kvalitet, rentabilitet og påvirkning af det omgivende miljø. Jordens frugtbarhed vil således være påvirket af driftsform og planteproduktionens teknologiske og økonomiske rammer

On the Job Search and the Wage Distribution

Estimates of the structural parameters of a job separation model derived from the theory of on-the-job search are reported in this paper. Given that each employer pays the same wage to observably equivalent workers but wages are dispersed across employers, the theory implies that an employer's separation flow is the sum of an exogenous outflow unrelated to the wage paid and a job-to-job flow that decreases with the employer's wage. The specification estimated allows worker search effort to depend on the wage currently earned. The empirical results imply that search effort declines with the wage paid, as the theory predicts, using Danish IDA data for the years 1994-1995. Furthermore, the estimates for the full sample and four occupational sub-samples explain the employment effect, defined as the horizontal difference between the distribution of wages earned and the distribution of wages offered.

Validation of a novel image-weighed technique for monitoring food intake and estimation of portion size in hospital settings:a pilot study

AbstractObjectiveOptimal nutrition for hospital patients is crucial and routine monitoring of patients’ nutrient intake is imperative. However, personalised monitoring and customised intervention using traditional methods is challenging and labour-intensive, consequently it is often neglected in hospital settings. The present pilot study aimed to examine the reliability and validity of the Dietary Intake Monitoring System (DIMS) against the weighed food method (WFM).DesignThe DIMS 2.0 is composed of an integrated digital camera, weighing scale, radio-frequency identification sensor and WIFI connection for real-time image and weight dietary data acquisition and analysis. The DIMS equipment was used to collect data for a paired set of meals both before and after meal consumption at lunchtime.SettingOdense University Hospital, Denmark.SubjectsPhotos and weights of seventeen patient meals were captured.ResultsThe results showed a significant correlation between DIMS and WFM for energy (r=0·99, P&amp;lt;0·01) and protein intake (r=0·98, P&amp;lt;0·01). Intraclass correlation coefficients (ICC) revealed a high degree of agreement among the four non-trained assessors for estimates of portion size of each food item before (0·88, P&amp;lt;0·01) and after consumption (0·99, P&amp;lt;0·01). The ICC for energy and protein intake were 0·99 (P&amp;lt;0·01) and 0·99 (P&amp;lt;0·01), respectively. Bland–Altman plots revealed no systematic bias.ConclusionsConsidering the huge benefits associated with routine monitoring, technological advances have made it possible to develop a novel, easy-to-use DIMS that, according to the findings, is a valid alternative for use in hospital settings.</jats:sec

Appearance of β-lactam resistance genes in agricultural soils and clinical isolates over the 20th century

Debate exists about whether agricultural versus medical antibiotic use primarily drives increasing antibiotic resistance (AR) across nature. Both sectors have been historically inconsistent at antibiotic stewardship and, as a result, acquired bacterial AR has progressively increased over the 20th century. The question is which sector has most influenced changes in acquired AR. To examine this question, we quantified four broad spectrum β-lactam AR (ARG; blaTEM, blaSHV, blaOXA and blaCTX-M) and class 1 integron genes (int1) in soils archived since 1894 from Askov Experimental Station, Denmark. ARG levels were significantly higher in post-1940 soils that only received manure (M) versus inorganic fertilisers (IF) (paired-t test; p < 0.001). However, first appearance of each ARG varied over historic time; blaTEM and blaSHV between 1963 and 1974, blaOXA slightly later, and blaCTX-M in 1989, dates that parallel appearance of each ARG in hospital isolates, suggesting their parallel occurrence in animal manure and human patients. It is not possible to determine whether farm versus hospital AR appeared first, but archive data imply they are mutually influential. Interestingly, levels of β-lactam ARGs in the M soils, especially blaCTX-M, declined since the mid-1990s, which aligns with reduced non-therapeutic antibiotic use in Danish agriculture. These data suggest improved antibiotic stewardship can reduce soil ARG reservoirs, although it also shows reduced manure applications to agricultural soils should be included in prudent stewardship programmes

Nitrogen fertilizer value of animal slurries with different proportions of liquid and solid fractions: A 3-year study under field conditions

AbstractThe plant availability of manure nitrogen (N) is influenced by manure composition in the year of application whereas some studies indicate that the legacy effect in following years is independent of the composition. The plant availability of N in pig and cattle slurries with variable contents of particulate matter was determined in a 3-year field study. We separated cattle and a pig slurry into liquid and solid fractions by centrifugation. Slurry mixtures with varying proportions of solid and liquid fraction were applied to a loamy sand soil at similar NH4+-N rates in the first year. Yields and N offtake of spring barley and undersown perennial ryegrass were compared to plots receiving mineral N fertilizer. The first year N fertilizer replacement value (NFRV) of total N in slurry mixtures decreased with increasing proportion of solid fraction. The second and third season NFRV averaged 6.5% and 3.8% of total N, respectively, for cattle slurries, and 18% and 7.5% for pig slurries and was not related to the proportion of solid fraction. The estimated net N mineralization of residual organic N increased nearly linearly with growing degree days (GDD) with a rate of 0.0058%/GDD for cattle and 0.0116%/GDD for pig slurries at 2000–5000 GDD after application. In conclusion NFRV of slurry decreased with increasing proportion of solid fraction in the first year. In the second year, NFRV of pig slurry N was significantly higher than that of cattle slurry N and unaffected by proportion between solid and liquid fraction