Anaerobic capability for nutrients & ponds

[peter-devoil]

The ability to model both rice paddys and the waterlogged soils of Iowa requires modification of the soil nutrient module to operate under anaerobic conditions, and the development of a pond module to simulate the chemical processes occuring in rice ponds. Transitions between aerobic & anaerobic states are common in these systems, and it is expected that with the recent refactoring of the nutrient module that the work of Gaydon & Probert implemented in Apsim Classic will be a much simpler task than previously.

The work will take place in conjunction with the rice model. Key particpants are @andomariot , @sarchontoulis and @hut104 .

[sarahcleary]

@peter-devoil - can you please assign the appropriate people/developers?

[hol353]

@APSIMInitiative/rice @APSIMInitiative/soil