This afternoon I met with Gregg Sanford of the University of Wisconsin at their Arlington Research Station. This is where they have their cropping systems trial. ( http://www.WICST.wisc.edu )
This trial was started in 1990 and was designed to look at many factors of different farming systems effects on soil, economics, yield and other environmental factors.
There are six systems they are running. Three grain systems: conventional continuous corn,
no till corn soya bean rotation (these are drilled no till soya beans)
and organic corn, soya bean, wheat.
Then there are three forage systems: three years of alfalfa and one year corn, ( this is drilled first year alfalfa)
Then one permanent pasture system, which Gregg is standing in front of in the first picture. There is a dairy on site and they return manure to the plots before corn. They try to treat each plot separately as a field as a farmer would.
They have had some interesting results. The pasture system is the only one that the carbon in the top few inches has stabilised in terms of the amount of C. All the rest have lost carbon over time. All of the systems have lost carbon from the depths of two to four feet. They think there is a few reasons for this. One could be climate. The other is that in the annual systems the carbon is not being replenished at depth as there are not many roots there. Even in the pasture system the roots are not as deep as the original prairie grass. Even the deep rooting alfalfa has not replenished this carbon as the roots are course and not fine. They reckon when this land was first tilled out of prairie they lost 50% of the soil carbon in the first decade or so.
In terms of yields the continuous corn yield about 180 bushels but the corn in the alfalfa rotation yields 220 bushels and the organic corn about 215 bushels.
In terms of economics the organic systems and the forage systems have the best return. The organic systems as their is a premium for the produce and the pasture system as the overheads are so low (no need for expensive machinery)
They have done many studies on the trial which can be found on their website. They also have included a plot of native prairie grasses to see the effects on the soil.
Gregg has recently been to the UK for a conference on systems trials at Newcastle University. It seems that systems research is becoming more recognised which is great for us farmers as it should give us more relevant results for out in the field.
Thanks to Gregg for the visit. It was a shame is was short as I am sure we could have chatted for ages .