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Task ID:  4093  Kill crop doesn't eliminate all biomass in AgPasture    
 
Created by rcichota on 2015-10-06 2:06 PM, 961 days ago
Project:  Module Code
Category:  Bug
Priority:  [no priority]
Assigned to:  rcichota  
Status:  re-opened
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 comment 42646 posted by har297 on 2017-07-25 10:04 AM, 303 days ago 

Good to see you will fix this Rogerio. A note to keep in mind. There is a discinction between 'dead' and 'senesced' that you may not be awae of. This came about to handle partial death of a population due to stresses, thus when a portion of the population died, its 'states' were transferred to a 'dead' population which still had a canopy to shade soil and compete for light interception with the 'live' portion of the population. Thus the 'ini' file has 'dead' related parameters. e.g.

      <y_extinct_coef_dead>0.30 0.30</y_extinct_coef_dead>
      <root_dead_detach_frac description="fraction detached from each part of a dead plant per day.">0</root_dead_detach_frac>
      <leaf_dead_detach_frac>0.0</leaf_dead_detach_frac>
      <stem_dead_detach_frac>0.0</stem_dead_detach_frac>
      <pod_dead_detach_frac>0.0</pod_dead_detach_frac>
      <meal_dead_detach_frac>0.0</meal_dead_detach_frac>
      <oil_dead_detach_frac>0.0</oil_dead_detach_frac>

Thus, while 'senesced' material is attached to the live plants and then becomes detached as it drops to the surface organic matter, 'dead' is a whole plant that is entirely killed - I don' recall if the roots are immediately transferred to the FOM soil pool on death - probably should be. 'KillCrop' or 'kill_crop' is a manager action that kills part or the entire live population, which becomes a standing dead population until end_crop transfers all components to both 'dead' and 'live' populations to other system pools.

This all relates to crops and I don't know how this applies to pastures.

Hope this helps to clarify the issues involved here.

 comment 39089 posted by rcichota on 2015-12-09 12:56 PM, 897 days ago 

Following comment from John Hargreaves, the method EndCrop should be added to dispose off all biomass. This will make AgPasture behaviour align with other apsim crops

 comment 38057 posted by har297 on 2015-10-07 6:20 PM, 960 days ago 

Be careful - I don'tthink other crops in APSIM do this and they should not be eliminating all biomass on kill crop. This happens on EndCrop.

The actions should be -

Harvest: remove grain of harvestable material.

KillCrop: move all green material to dead material, leaving the crop standing in the ground with roots attached. No growth occurs because the plant is dead but still exists.

EndCrop: Remove the plant from the system by dropping all above ground material to the surface organic matter pools and all below ground matter to FOM pool in the soil.

 comment 38056 posted by rcichota on 2015-10-07 11:24 AM, 960 days ago 

The method has been fixed, that involved making sure that all DM and N pools were set to zero for each species, AND then run the UpdateAggregated() method to update the sward variables.  The addition of all DM to soil (roots) and SurfaceOM (aboveground) were already correct.

 comment 38052 posted by rcichota on 2015-10-06 2:06 PM, 961 days ago 

When using OnKillCrop() with AgPasture, the above ground biomass is not removed. It doesn't grow. The roots are removed (added to soil FOM). The above ground biomass should thus be added to SurfaceOM