Algemeen

There seems now to be an entire disconnect in people’s minds between plants and our utter dependence on them. It is perhaps understandable that the general public may not understand the concept of primary production, the plant manufacture of sugars and other organic compounds via photosynthesis, which lies at the basis of life on Earth.

Earth Day, which was April 22, reminds us that life is a web, of which humans are an integral part. We think of ourselves as depending on grains and vegetables and meat for survival, but really it is the host of invertebrates and microbes that form the base of the pyramid of life, without which our carrots and cows could not exist. The use of persistent pesticides in our yards and farms poses a threat to the life forms that support us. Neonicotinoid insecticides are a class of poisons that persist for years in leaves, stems and roots of plants.

Like many other area farmers, the Bredeson family in Harvey Township, between Grove City and Litchfield, buys corn and soybeans seeds treated with pesticides. Pesticides are designed to improve crop yields, but they have side effects, and the family has been learning more about these effects from an expert — Mark and Julie Bredeson’s own son, Michael. “He’s kind of on the cutting edge of finding that these pesticides that farmers have been using for many years have become a detrimental thing to not only agriculture but mother nature,” Julie said about Michael’s work. Michael, a 2008 Litchfield High School graduate, is pursuing his Ph.D. at South Dakota State University, where he studies the effects of pesticides on organisms, particularly linked to sunflowers, a common cash crop in South Dakota. In commentary in the Independent Review (see below), Michael writes about pesticides’ effects and the long-term implications for birds, reptiles, mammals, fish and plants. Julie and Michael said they’ve both noticed a reduction in wildlife at and near the family’s Meeker County farm over the years. As he grew older, Michael noticed a decline in good fishing holes, which he attributes to runoff from crop fields. “My life revolved around fishing on all the little lakes. A few of my great fishing spots died off, and that kind of irritated me, of course,” he said. Julie said she’s also witnessed a decline in wildlife since she was a child. “The landscape as far as our wildlife, butterflies and bees, has dramatically changed,” she said. “It’s something we need to think about.”

The first ever Britain-wide assessment of the value of wild flowers as food for pollinators, led by the University of Bristol, shows that decreasing resources mirror the decline of pollinating insects, providing new evidence to support the link between plant and pollinator decline. In recent years, there have been considerable concerns over threats to wild bees and other insect pollinators which are vital to the success of important food crops and wild flowers. Amongst the many pressures facing pollinators, a key factor is likely to be decreasing floral resources in Britain. The study, published today in Nature combines vegetation survey data recorded over the last 80 years with modern day measurements of nectar to provide the most comprehensive assessment ever published. In the study, researchers from the University of Bristol and University of Leeds worked with scientists from the Centre for Ecology and Hydrology and Fera Science Ltd, to find substantial losses to nectar resources in England and Wales between the 1930s and 1970s – a period closely linked with agricultural intensification.

Although pesticide treatment for oilseed rape (OSR) will vary from place to place and year to year, depending upon local conditions and needs, this review of pesticide usage on OSR between 1988 and 2014 has identified a long-term upward trend. Overall, the average number of pesticide treatments on OSR has more than doubled since 1994, accompanied by an increase in weight of pesticide active substances, from 2.1 kg/ha in 1994 to 3.3 kg/ha in 2014. The combined number of pesticide active substances has more than doubled during the same period. In respect of insecticides, the weight of insecticide active substances per hectare increased from 32 g/ha in 2002 to 50 g/ha in 2014. The number of insecticide spray rounds, products and active substances has also increased since 2002. Although Budge et al (2015) established that neonicotinoid seed coatings enabled farmers to reduce the number of insecticide sprays on OSR, this is not evident from the survey data after 2000 when neonicotinoid seed treatments were introduced. The weight of insecticide active substance per hectare and the number of insecticide spray applications has continued to increase after the introduction of neonicotinoid insecticide seed treatments in 2000.

On an independent modern farm followed by certified veterinarians, dairy cows (mean of 62 per year) were maintained in optimized milk production for 3 years each. From 1997 to 2002, just after the commercial release of the first GMO (genetically modified organism) in Europe, genetically modified (GM) Bt176 maize grown on the farm was progressively introduced in controlled diets. The results are described in the following account, which has an historical value as it is the longest and first on-farm observation of mammals, performed by an experienced farmer and veterinarians, during a period of unusual pathological problems in cows receiving a GMO-rich diet. Thus it was not designed as a scientific experiment. Over the years, and coinciding with regular increases in GMO content of the diet (0–40%), the proportion of healthy cows with high milk yield diminished from 70% (normal rate) to only 40%. At the peak of mortalities in 2002, 10% of the cows died, preceded by a long-lasting paresis syndrome without hypocalcemia or fever, but with kidney biochemical failure and mucosa or epithelial problems. No microbial origin was identified, though intensively investigated. The GM maize, subsequently withdrawn from the market, was at the time the only intended managerial change for the cows. It is proposed that it provoked long-term toxic effects on mammals, which are not observable in most common conditions of intensive farming with high and rapid animal turnover and with no specific labels on GM feed (identifying amount and precise identity of GMO content). More long-term assessments during GMO feeding trials should be performed.

Die meisten Lebensmittel aus konventioneller Landwirtschaft sind so stark mit Rückständen von Insekten- und Unkrautvernichtungsmitteln belastet, dass sie nicht als Säuglingsnahrung verkauft werden dürften. Demgegenüber halten 95 Prozent der ökologisch erzeugten Produkte den Grenzwert für Säuglingsnahrung von 0,01 Milligramm pro Kilo ein. Das zeigt eine Studie, die der renommierte Pestizid-Experte Lars Neumeister im Auftrag der Grünen im Bundestag erstellt hat. Der Studienautor wertete die Ergebnisse von fast 58 000 Stichproben aus, die die Lebensmittelüberwachungsbehörden der 16 Bundesländer in den Jahren 2011 bis 2013 untersucht hatten. Eindeutiger hätte das Ergebnis kaum ausfallen können: In allen 37 Produktkategorien – vom Apfel bis zur Zitrone - wiesen Bio-Lebensmittel deutlich niedrigere Rückstandsgehalte auf als die konventionellen Vergleichserzeugnisse.