UPDATE

farm_hub/services.py

@@ -1,21 +1,25 @@
 from django.db import transaction
 
-from crop_zoning.services import create_zones_and_dispatch, get_initial_zones_payload, normalize_area_feature
+from crop_zoning.services import (
+    create_zones_and_dispatch,
+    get_default_area_feature,
+    get_initial_zones_payload,
+    normalize_area_feature,
+)
 
 
 def dispatch_farm_zoning(area_feature, farm):
     crop_area, _zones = create_zones_and_dispatch(normalize_area_feature(area_feature), farm=farm)
-    return get_initial_zones_payload(crop_area)
+    return crop_area, get_initial_zones_payload(crop_area)
 
 
 def create_farm_with_zoning(serializer, owner):
-    area_feature = serializer.validated_data.pop("area_geojson", None)
+    area_feature = serializer.validated_data.pop("area_geojson", None) or get_default_area_feature()
 
     with transaction.atomic():
         farm = serializer.save(owner=owner)
-        zoning_payload = None
-
-        if area_feature is not None:
-            zoning_payload = dispatch_farm_zoning(area_feature, farm)
+        crop_area, zoning_payload = dispatch_farm_zoning(area_feature, farm)
+        farm.current_crop_area = crop_area
+        farm.save(update_fields=["current_crop_area", "updated_at"])
 
     return farm, zoning_payload