Jeff:

Good session, but I see a big gap.  There needs to be discussion about
modeling the impact of crop residues/tillage on soil temperature.  I don't
think the residue/tillage effect on evaporation is enough to highlight this
effect, especially if done in a rather simplistic way.  In my opinion,
possibly up to half of the effect of the no-tillage/residue effect on crop
production in northern USA is the cooler soil temperature experienced.  We
will not get it right until soil temperature is also addressed.  Who will
work on that?

Ken Boote

At 11:34 AM 2/28/03 -0700, you wrote:
>Colleagues,
>
>Please see the notice below for information on a special session to look
>at strategies for modeling effects of tillage and no-till.
>
>Best regards,
>Jeff
>
>
>
>Special Session on Modeling Tillage at the 2003 Meetings of the
>ASA-CSSA-SSSA, November 2003, Denver, Colorado
>
>Few simulation models attempt to model effects of tillage and residue
>management with sufficient detail to represent expected differences
>between conventional tillage and no-till systems. During the business
>meeting of Division A-3 of the American Society of Agronomy in 2002, the
>suggestion was made to hold a special session of A-3 to look at approaches
>
>for modeling tillage. The overall objective would be to assess current
>approaches to modeling tillage and suggest possible research activities
>over the next few years. Possible topics to cover in the session would
>include:
>- Agronomists' perspective of modeling needs for conservation agriculture:
>
>high input systems
>- Agronomists' perspective of modeling needs for conservation agriculture:
>
>low input systems
>- Modeling soil water balances when mulch layers are present
>- Modeling residue incorporation and decomposition
>- Modeling soil biological activity
>- Modeling tillage effects on soil physical properties
>- Modeling carbon sequestration
>- Documenting tillage and residue management practices for model inputs
>and validation
>         Individual talks would be 20 minutes long and depending on
>interest, we would have a half or whole day session. At the end of the
>session, a brief summary would be given, followed by an open discussion on
>research needs and approaches.
>         If you are interested in presenting papers during this session,
>please contact:
>Rolf Sommer, CIMMYT, [log in to unmask] (Tel. 52-55-5804-2004 Ext. 2128)
>Jeff White, US Water Conservation Lab, [log in to unmask]
>            (tel 602-437-1702, ext 268)
>
>Please note that participants should submit title summary forms through
>the ASA web site by 27 March. We regret that no funds are available to for
>travel costs or registration fees.