Soil tilling and drying are important processes in nursery pond operation. Tilling loosens and aerates compacted soil, mixes organic matter and nutrients, destroys weeds, and helps dry wet soil before seeding. Drying removes water from the pond bottom through evaporation, cracking the soil to mineralize it and eliminate fish predators. An ideal drying period is a minimum of two weeks to eradicate pests, hasten decomposition of organic matter to release nutrients, harvest all fish, and kill disease-causing organisms. The pond bottom should dry until cracks form or the soil can support weight without sinking more than 5 cm.

1. Soil Tilling and Drying

2. Objectives:
•Identify soil tilling and
drying.
•Discuss its purpose in
nursery pond operation.

3. Soil Tilling

4. - is simply turning over and breaking up the soil.
Exactly how deep you till and how fine you break up
the soil depends on your reason for tilling. To make the
task of tilling easier, you can purchase or rent an
engine-powered tiller from a garden supply center.
These tillers are great for large areas, but if you only
have a small area, try a cultivator fork or a deep spader
or cultivator to loosen up compacted soil.

5. Why You Need to Till:
• Soil becomes compacted over a period of years from
rain and foot traffic.
•Loosens and aerates the top layer of soil or horizon, which
facilitates for the next operations
•Helps mix harvest residue, organic matter (humus), and
nutrients evenly into the soil
•Mechanically destroys weeds.
•Dries the soil before seeding (in wetter climates tillage aids
in keeping the soil drier).

6. Drying
•is a mass transfer process consisting
of the removal of water or another
solvent by evaporation from a solid,
semi-solid or liquid.

7. •The pond bottom should dry out until it
cracks. This mineralizes the soil and helps in
eliminating fish predators. Drying period of a
minimum of two weeks or longer is ideal
depending upon the weather and pond
bottom conditions.

8. Purposes of pond drying
• 1. to eradicate fishpond pests, predators and
competitors
• 2. to hasten the chemical decomposition of
organic matters deposited so that nutrients will
become available for the growth of fish food in
the fishpond
• 3. to totally harvest the fish stock
• 4. to kill disease causing organism

9. •Dried until the soil cracks or
when it is firm enough to hold
one's weight without sinking
more than 5 cm on walking over
the surface