The Lancet article that shows in a bad light the consumption of meat foods, eggs and potatoes can, unless there is qualified rebuttal, have a disastrous effect on agriculture as we know it.
I do not feel qualified to deal competently with health aspects that might arise from consumption of the products referred to, but I am in an authoritative position to deal with certain environmental aspects relating to the production of the sources of the preferred diets, and of other crops grown in soil.
It is fashionable to condemn ruminants for their production of methane, a potent greenhouse gas (GHG). But no account is taken of the potential we now have to greatly lower their GHG emissions.
There is, however, a far more serious environmental matter that is not being considered. The most fertile soils of the world are under long term cultivation and that is leading to the depletion of soil organic matter (SOM). From studies compiled by Rattan Lal of the Ohio State University, president of the International Union of the Soil Sciences (IUSS), it is estimated that 50-100 crops from now the SOM in such soils will be depleted, the soils degraded, and productivity lost.
Maize (Zea mays L) is widely grown in these soils and that is a major source of feed for ruminants, pork, and poultry in other parts of the world.
Maize has an extensive root system, and if the stover and cobs (after shelling) are returned to the soil then the SOM losses will be greatly lessened, but additional amendments will be required even where conservational tillage is used. That is not happening. The leading soil research texts, ‘The Chemistry of Soil Constituents’, and The Chemistry of Soil Processes’, had a theme nearly two generations ago which stated that “All that is produced from soil that is not used for fuel and fibre should be returned to the soil”. That should include soil applications of sewage sludges, excellent sources of mineral plant nutrients and of organic matter, and pathogen free when subjected to aerobic thermophilic digestion (which has minimum energy requirements). That also is not happening.
It should be remembered that when SOM is decreased because of cultivation, the loss of CO2 from the indigenous SOM is the same as fossil C in terms of global warming.
Now the crops that provide the major food sources suggested in the Lancet initiative have deleterious effects where SOM is concerned when long term cultivation is practised. That would mean that 50 years or so from now it will be difficult to feed, from the diets suggested, the predicted population of upwards of 10 billion. The crops for most of the foods recommended will contribute little to the SOM contents and lead to more rapid degradation of the indigenous SOM.
I have heard interviewees extol the academic excellence of Walter Willett , the outstanding nutritionist from Harvard (who has led the Lancet initiative). and also that of the other scientists associated with him in that initiative The academic excellence of Willett is unquestionable (ISI h index of 98). But his outstanding rating is significantly exceeded by that of Lal (ISI, h index of 108; Google Scholar h index of 140, and with an amazing i10 of 969). Similar impressive indexes apply for Roger Swift, (University of Queensland) and for Donald L Sparks (University of Delaware), presidents of IUSS earlier this century, who share some similar research experiences and successes as Lal, and their such accomplishments are significantly greater than those of most of the contributors to the Lancet report.
Adherence to the Lancet recommendations would have disastrous consequences for Irish agriculture as we know it now. But it should be remembered that, despite what detractors say, Ireland has one of the most environmentally benign agricultural systems in the world because greater than 90% of our soils are under long term pasture, peat, and forestry, and because of that, we have per head of population more sequestered C in our soils than any (with the possible exception, of Finland) other country in the EU. But we are not getting credit for that. STRIVE 58, in the STRIVE 2007-2013 EPA reports, shows the extents to which our SOM would be degraded in a generation should long term cultivation practises be applied for cereal production in our soils.
We have dispersed throughout this country the research skills that can bring about the lowering of methane emissions from ruminants, the elimination of nitrous oxide from soils and of ammonia from slurry pits, the prevention of eutrophication from fertilizer runoff, and the amelioration of other environmentally deleterious consequences that are being attributed to agriculture.
It will be very appropriate to convene the persons with the necessary skills and initiate a centrally based research effort funded by the state and best coordinated by SFI.
Ireland, should that happen, could soon be confirmed as the world leader in environmentally benign agricultural production.
Dr Michael HB Hayes MRIA,
Hon research professor Carbolea Group
University of Limerick