• Mark Measures

Management affects soil and food quality

"A nation that destroys its soil destroys itself." Franklin D Roosevelt

The Rodale Institute

Rodale in Pennsylvania is best known for its long-running Farming Systems Trial, comparing organic management with conventional, so an ideal place to start my trip. 300 acres with arable, vegetables, pigs and cattle, the farm has an ambitious research programme. Being at the forefront of organic research in the US, it is amongst a very select group of well-established organic research centres around the world, including FiBL in Switzerland and the Organic Research Centre in the UK. Jeff Moyer, Director and Dr. Kristine Nichols were my hosts.

The Farming Systems Trial with full replicates has been running for 35 years, and provides exceptional evidence of the beneficial impact of organic farming compared to conventional. Organic stocked and organic stockless systems outperform in terms of soil structure, biological activity, organic matter levels, water percolation and drought resistance. Intriguingly organic yields are comparable with conventional – I have not yet got to the bottom of that; this is not the experience elsewhere, which is that organic cereal yields are 50 – 60% of conventional.

Soil organic matter levels increased from 3.5 to 4.2% over the first 20 years, thereafter stabilising. Rodale think that levels can be further increased by changes in management, though I rather doubt this as it is generally not possible to continually increase levels, particularly in a cropping systems and cultivations, where carbon breakdown and cycling is a part of the fertility system. We need to be particularly careful not to extrapolate the results from on situation to another, changes in soil organic matter will not necessarily be the same in different soil and climatic conditions. More information is available here

Good success has been achieved with Rodale’s pioneering development of the crimper-roller as a means of no-till organic cereal cropping, which might help build organic matter levels.

Rodale places a unique emphasis on soil health and nutritional value of the food produced. This is driving a new research programme:

Vegetable Systems Trial. This new long-term trial is comparing organic and conventional soil management methods, with an important and under researched focus on nutritional quality. The aim is: “monitoring soil health, vegetable nutritional quality, environmental impact, agroecosystem resilience, and the economics of vegetable production over time while assessing how management practices directly or indirectly affect human health.” It is early days but already the use of cover crops is showing an effect on soil organic matter. I do however wonder why the rotation includes cropping every year, without what I would consider a necessary year or two of fertility building.

Ergothioneine is an amino acid with antioxidant properties, produced by certain fungi and assimilated by livestock grazing affected soils and passed on to humans consuming products from the livestock or vegetables grown on such soils. Rodale believe that this amino acid is involved in the human immune system, and particularly having an effect on cancer development. Trials are at an early stage of soil fungal inoculation and monitoring crop Ergothioneine levels.

Crimped rye, direct drilled maize and rye cover crop

Soil analysis methods I will report on after my visit to Cornell; Rodale uses their standard service.

In addition they are using the Haney soil analysis programme, which integrates soil biology and mineral analysis. It relies on use of the Solvita respiration analysis, as does NRM (UK) and both labs provide a Soil Health Service, in the case of Haney including reserve and available forms of P, total N and organic N, water extractable C and C: N ratio. Kris Nichols is quite positive about the use of the analysis results, however her view is that the Solvita test is quite basic and probably does not give a genuine assessment of aerobic bacteria activity but does provide a useful start in assessing soil life. My previous experience with soil life assessment offered under the Soil Food Web banner, which does a count of key fungi and bacteria, is that it is prohibitively expensive and not offering established organic farmers a useful, validated basis for soil management recommendations. It is perhaps useful for conventional and converting growers following soil sterilisation.

What I find surprising is that there is little earthworm monitoring going on; a tangible approach, easily done by farmers and which is closely related to soil structure, health and productivity.

On another note, Rodale are instigating a new organic certification scheme, incorporating some important elements of organic farming, such as growing in soil and long term farming systems, both of which are currently being flouted by NOP certifiers in the US, Argentina and perhaps elsewhere. Social criteria including conditions for farm workers are also to be included.

43 views0 comments

Recent Posts

See All

Monitoring soil organic matter

NRM Carbon Check soil analysis service NRM is now offering a new Carbon check soil analysis service