Susceptibility of spelt to ochratoxin A producing fungi

The susceptibility of spelt to ochratoxin A producing fungi has been investigated

Fungi in Danish soils under organic and conventional farming

A multi-soil study was conducted in Denmark including 29 sites, 8 classified as ‘Organic’, 11 as ‘Conventional with manure and synthetic fertilisers’ and 10 as ‘Conventional with synthetic fertilisers’. The variability of fungal abundance within the three farming systems and the long-term effects of different farming systems on fungal propagules in soil were evaluated. Fungal abundance showed large variations within all three farming systems and this variability reduced the possibility to obtain general conclusions on fungal composition in soils under different farming systems. This was illustrated by the results on total propagule numbers of filamentous fungi and yeasts. Penicillium spp. and Gliocladium roseum were more abundant under organic than conventional farming, while Trichoderma spp. were most abundant in conventionally farmed soils with synthetic fertilisers. These results were not altered after adjusting for possible differences in basic soil properties like total-C and N, extractable P, CEC, base saturation and soil density. The paper discusses whether the differences in fungal abundance are characteristics of a farming system itself or associated with certain management factors being more prevalent in one farming system than the other

Soil Quality Management - Concepts and Terms

The industrialization of agriculture and the concurrent increase in societal concerns on environmental protection and food quality have put focus on agricultural management and its impact on soil quality. Soil quality involves the ability of the soil to maintain an appropriate productivity, while simultaneously reducing the effect on the environment and contributing to human health. This development has changed society’s expectations to science and there is an urgent need to improve the communication among researchers from different scientific disciplines. The interaction of scientists with decision-makers is a topic of utmost relevance for future developments in agriculture. Reflexive objectivity denotes the exercise of raising one’s consciousness of the cognitive context, i.e. societal priorities and the values and goals of the researcher. The term sustainability comprehends the priorities in the cognitive context and thus constitutes a valuable tool for expressing the basis of scientific work. Soil quality evaluations should include awareness of the stability of any given quality attribute to disturbance and stress. This implies addressing resistance and resilience of the soil functions and/or the physical form in question. Most existing literature on soil quality focuses on assessment of soil quality rather than the management tools available to influence soil quality. Identification of management thresholds rather than soil quality indicator thresholds is suggested as an important means of implementing the soil quality concept. The major challenges facing modern agriculture include proper nutrient cycling, maintained functions and diversity of soil, protection of an appropriate physical form, and avoidance of chemical contamination. It is suggested that these challenges and problems as related to the soil quality concept are discussed in the framework expounded above

Forebyggelse af mykotoksinproblemer

Presentation of project PREMYTOX and some of its results at the "Night of Culture" 200

Low temperature handling will delay but not hinder ochratoxin A formation in wet grain

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

Svampegift dannes i korn på trods af nedkøling

Nye forsøg har vist, at kornets vandindhold har større betydning end temperaturen for dannelse af giftstoffet ochratoksin. I forebyggelsen er det derfor altafgørende at få kornet tørret hurtigt ned og undgå fugtige lommer

Sådan får man en god jordstruktur

En tung og knoldet jord er vanskelig at bearbejde. Det kan medføre et dårligt såbed og dårlig fremspiring. Og da en sådan jord også har få porer begrænses transporten af vand og ilt til planternes rødder. Herved forringes leveforholdene smådyr og mikroorganismer og der bliver en dårligere forsyning med næringsstoffer til planterne. For at få et godt såbed skal jorden have en god struktur – den skal gerne danne krummer (aggregater). De bygges op af jordens grunddele eller 'primærpartikler' ler og sand. Til at binde primærpartiklerne sammen kræves bindemidler. I danske jorde er biologiske bindemidler de vigtigste. Der findes to slags. Det ene er klisterstoffer, der dannes af planterødder, bakteri-er og svampe. Det andet er svampetråde (hyfer), der sammenvæver små krummer til større krummer. Leret selv kan også være bindemiddel, og det samme kan forskellige uorganiske forbindelser. I klummen beskrives resultater af undersøgelser på økologisk og konventionelt dyrkede jorde

Penicillium verrucosum occurrence and Ochratoxin A contents in organically cultivated grain with special reference to ancient wheat types and drying practice

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

Svampegift i korn kan måles med hurtig og billig metode

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

Soil aggregation – a matter of proper management

Soil crumbs are important to soil functions. These include plant growth, and the growth of fungi and bacteria forming agents for binding and bonding of new crumbs. We have studied how commercial organic and conventional farming affect this interaction. A diverse crop rotation, including grass, and animal manure resulted in stable crumbs with a high content of biological binding and bonding agents. A cash crop rotation with the addition of only synthetic fertilizers resulted in small, stable aggregates – more like clods - with clay as binding agent. Such a soil will provide poor conditions for preparing seedbeds, because prolonged rain makes it soft and muddy while drought makes it hard as brick