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New experiments have shown that grain moisture is more important than temperature for the formation of the mycotoxin Ochratoxin A (OTA). OTA is one of the most important mycotoxins on Danish grain. A fast and efficient drying procedure avoiding pockets of wet grain is crucial in preventing OTA formation.

Analyser af knap 100 kornprøver viser at en hurtig og billig testmetode giver resultater, der stemmer godt overens med en mere kompliceret metode til måling af ochratoksin fra svampe. Den simple metode kan anvendes både til forskning og til egenkontrol i mindre virksomheder.

This study addresses the relationship between the ochratoxigenic strains of Penicillium verrucosum and ochratoxin A (OTA) contents in organically cultivated grain. It included 37 combined, non-dried grain samples from farmers with no drying facilities as well as 19 non-dried and 22 dried samples from six farms with on-farm drying facilities (Case studies 1-6). The study focused on the ancient wheat type spelt but also included samples of wheat, rye, barley, oats, triticale, emmer, and einkorn. All 78 samples were analysed for moisture content (MC) and occurrence of P. verrucosum. The latter was assessed by plating non-disinfected kernels on DYSG agar and counting those contaminated by the fungus. Fiftyfive samples were analysed for OTA. Most of the combine harvested samples (82%) were contaminated with P. verrucosum prior to drying. This was ascribed to difficult harvest conditions and many samples of spelt, which was significantly more contaminated by P. verrucosum than oats, wheat and barley. Though not statistically significant, the results also indicated that spelt was more contaminated than rye, which is usually regarded the most sensitive small grain cereal. No correlation was found between number of kernels contaminated by P. verrucosum and OTA content. Despite many non-dried samples being contaminated by P. verrucosum, only two exceeded the EU maximum limit for grain (5 ng OTA g-1), both being spring spelt with 18 and 92 ng g-1, respectively. The problems were most likely correlated to a late harvest and high MC of the grain. The case studies showed exceedings of the maximum limit in a batch of dried oats and spring wheat, respectively, probably to be explained by insufficient drying of late harvested grain with high MC. Furthermore, our results clearly indicate that OTA is not produced in significant amounts in samples with MCs below 17%. All dried samples with MCs above 18% exceeded the 5 ng OTA g-1 limit in grain. However, no correlation between MC and the amount of OTA produced was found.

Når jordbundens mikroorganismer og smådyr har det godt, er jorden som regel også god at dyrke planter i. Og jordbundens levende organismer trives, hvis de får rigeligt med næring og fred og ro. Det første kan økologiske jorde levere, men på grund af mekanisk ukrudtsbehandling ofte ikke det sidste. En mindre del af de konventionelt dyrkede marker giver jordbundsorganismer lige så gode betingelser, så økologisk dyrkning er ikke en absolut betingelse for et godt jordliv.

Ligesom der findes vandkvalitet, luftkvalitet og fødevarekvalitet, findes der jordkvalitet. Og jordens kvalitet hænger nøje sammen med dens struktur, f.eks. dens indhold af partikler og porer. Dette kapitel handler om, hvordan økologisk og konventionelt landbrug påvirker jordkvaliteten. På nogle områder er økologisk landbrug bedst, men ikke på alle.

Soil structure is an important element of soil quality since changes in structural characteristics can cause changes in the ability of soil to fulfil different functions and services. Emphasis in this chapter is placed on the role of soil structure in biological productivity of agroecosystems. Combinations of management practices in which the extent of the degradation of soil structure caused by one practice is balanced or exceeded by the extent of regeneration by other practices will help sustain the productivity of agroecosystems. Tillage and practices that change the organic matter (OM) content of soil are foremost among the many practices that influence soil structure. The links between management, OM content and soil structure and between tillage and soil structure are explored. The feasibility of defining management thresholds or soil quality indicator thresholds with respect to soil structure is assessed.