Filling the Columns and Inoculating the Biota for Leachate Collection to Study Mineral Weathering

To begin, construct the refrigeration for leachate collection and the mesh system at the bottom of the columns. Weigh 400 grams of minerals and 10 grams of organic materials in a bowl according to the desired treatment. Then, calculate the water holding capacity using the equation shown here.

Adjust the water holding capacity to 80%based on the mineral type, grain size, and organic source. Mix all the components cautiously using a metal spoon, and fill the columns with the thoroughly blended mixture. Position the filled columns in the climate chamber.

Then, take the prepared microbial cultures. Using a pipette, inoculate the selected culture on the surface of the columns as per the desired treatment. Acquire earthworms as per the desired density, and carefully place them on the surface of the columns as per the desired treatment.

Place the mesh on top of the columns to avoid earthworms'escape once they are introduced, and to columns without earthworms to maintain the same conditions. Then, insert the columns at the respective places in the acrylic sheet too. After setting up the irrigation and control system, click the Edit button to edit the settings of each task.

To activate the relay, simply click on the task that requires the relay to be turned on. Then, insert the preferred settings in the Start Date and Start Time fields to set the start date and time for the operation. Click Set Repeat and Repeat Every to set the watering frequency.

To specify the date and time when the relay should stop operating, click on the End Repeat Date and End Repeat Time fields. After entering the desired values, click the Save Changes button. To turn off the relay, click on the task for which the action is to set the specific relay off.

Set the time at which the relay must stop working depending on the water irrigation rate and the watering frequency following the same commands as to set the relay on. Once each relay is set, click on Save Changes. The irrigation system will then start watering the columns according to the set flow rates and frequencies.

The irrigation system allowed water adjustments in the columns, leading to small differences in irrigation rates. The average amount of water was lower for irrigation rates of 50 and 150 milliliters per day, while it was higher for an irrigation rate of 100 milliliters per day. Values for dissolved inorganic carbon measured at the end of the experiment ranged from 7.352 C to 259.279 milligrams carbon.

At the end of the experimental period, earthworms successfully survived in this organomineral system, and visual signs of microbial growth could be detected.