Land Info / Inchclutha Delta

Alert Title	Alert Details	Alert Type	Alert Threshold Level
Above Capacity	Irrigation should cease when soil moisture percentage is above field capacity (Above the red zone)	High Level	48.00

Inchclutha Delta - Soil Moisture and Rainfall

---- Soil Moisture
---- Rainfall

The above soil moisture plot shows the percentage of moisture in the top 200 mm of soil (Left hand axis). Soil moistures are separated into three zones: Red, Yellow and Green Zone, with the Field Capacity line at the top of the Red Zone showing the maximum amount of water that the soil can hold. Guidance for effluent irrigation management is set out below with reference to these three zones. Rainfall on a daily basis is shown on the right hand axis.

Key:
Field Capacity: The maximum amount of water the soil can hold is expressed as a percentage of soil volume and for this soil the field capacity is 50%. This means there is 100mls of water in the top 200mm of soil when the soil moisture is at field capacity of 50%.

Permanent Wilting Point: When the soil moisture falls to this level, plants have wilted and will cease to grow.

Soil type: the soil type at this site comprises Koau deep silt loam (Gley soil type) on gently undulating terrain and is poorly drained in its natural state. This drainage pattern has been modified through the inclusion of open drains which improves soil health and pasture growth. The presence of open drains does however increase the risk of excess effluent application draining away and entering water when soil moisture levels are high (refer to guidance section below). Also a high water table in this area increases the risk of excess effluent application draining through to groundwater when soil moisture levels are high.

Guidance for effluent management - with a travelling irrigator.

Red Zone: between (40.5% - 48% Soil Moisture)
Effluent irrigation with a travelling irrigator should not occur when readings are within the Red Zone as soil moisture is considered to be too close to Field Capacity. There is a high risk that the effluent would make its way into waterways either by overland flow or via drainage through mole/tile drains.

Yellow Zone (33% - 40.5% Soil Moisture)
Effluent irrigation with a travelling irrigator may commence with caution when readings are within the Yellow Zone. Irrigation needs to be carried out with care. A travelling irrigator needs to be set at maximum travelling speed as there is still a medium to high risk for effluent to enter waterways either by overland flow or via drainage through mole/tile drains.

Green Zone (below 33%)
Effluent irrigation with a travelling irrigator can operate within the Green Zone with a much reduced risk of effluent entering waterways either by overland flow or via drainage through mole/tile drains, provided best management practices for irrigating are followed and the irrigator remains set at maximum travelling speed. Be cautious with effluent application when the soil is extremely dry as effluent may move straight to tile drains via soil cracks.

Guidance for effluent management - with Low Rate/K line

Red Zone: between (40.5% - 48% Soil Moisture)
Effluent irrigation using a low rate/K-line system should be delayed when readings are closer to the Field Capacity line (within the upper section of the red zone), as there is still some risk that the effluent would make its way into waterways through mole/tile drains. Small applications of effluent (< 10 mm) can be made with caution when readings are within the lower section of the red zone.

Yellow Zone (33% - 40.5% Soil Moisture)
Effluent irrigation using a low rate/K-line system can generally be carried out within the yellow zone with a much reduced risk of effluent entering waterways through mole/tile drains.

Green Zone (below 33%)
Effluent irrigation using a low rate/K-line system can operate within the green zone with minimal risk of effluent entering waterways through mole/tile drains, provided soil moisture conditions have not reached a level where soil cracking may appear.

Inchclutha Delta - Soil Temperature

Key:
Red Line: This is a trend line which also takes into account records over the preceding four days.
Yellow Line: This line shows the soil temperature recorded on an hourly basis.