<snips>
>One problem is that in
>complex systems, applicable factors are numerous, and these experiments can
>grow very, very large to accomodate conceivable interactions.
>
>Anyhow, designing experiments like this is a can of worms, but kind of fun
>if you have the right perspective, like finding the right lure to catch a
>fish.
An analogy I can appreciate from exerience.
I keep coming back to the basic question: What genetics should I use on my
farm?
I wrote an article for The New Farm probably 10 years ago on best corn
genetics for sustainable systems. If I recall correctly, the primary
source for the article was a Pioneer agronomist (whose name escapes me now)
who was based in Iowa (I think he's in Minnesota now) and had a good grasp
of sustainable systems. From memory, here's what he and the other sources
advised:
*Start with locally adapted genetics. Chancese are good that the numbers
that work in your area under conventional systems will also do well under
sustainable management.
*Run your own test plots. The more your soils and management differ from
the soils and management where the companies and universities run their
test plots, the more you are likely to see differences in how the various
genetics behave under your conditions. Here's where you can check out some
of the alternatives like OPs and see if they make more sense with your system.
*Shorter season genetics? Many sustainable farmers have fewer corn acres
to plant and often wait until soils warm to optimum temperatures to give
the crop a jump on the weeds. So you might want to see how shorter-season
genetics work in your system. Don't forget to factor in the economics of
drier corn at harvest.
*Good early season vigor. (Not that I've ever seen any numbers touted as
slow starters.) You want corn that gets out of the ground quickly if
you're relying on rotary hoeing and cultivation to control weeds.
*"Race horse" vs. "Work horse" hybrids. This relates to the different
nutrient cycling found in sustainable systems. With conventional
management, available N is often high early in the season from preplant
applications, then tapers off quickly during the growing season. So you
want a "race horse" hybrid that takes up N quickly early in the season.
Sustainable systems that rely more on mobilization of N from organic
sources (cover crops, manure, compost) tend to have relatively low
available N early in the season. But the soil tends to keep mobilizing N
longer in the season. So you want a "work horse" hybrid that can use N
efficiently throughout the season, not just cash in on the early spike in
soil N. If I recall, the source suggested looking for numbers with "stay
green" characteristics.
This info is a decade old (and probably clouded a little by my faulty
memory). Are these still the main considerations sustainable farmers
should have when choosing corn genetics?
Craig
Craig Cramer
mailto:cdcramer@clarityconnect.com
1,000 Ways to Sustainable Farming
http://1000ways.baka.com
Sustainable Farming Connection
http://sunsite.unc.edu/farming-connection
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