National Geographic 08.2019

Seeds

LED lamp

Peat, foam, or

other growing

material

Seedling

SUMP

PUMP

GROW BED

Polystyrene

raft

Roots

Bibb lettuce

Filters

100 ft

COMMERCIAL
SYSTEM

Rearing tanks Grow beds

Nitrates

DECODER BY MONICA SERRANO

ALEXANDER STEGMAIER. ART: DAVID KILLPACK. SOURCES: DONALD BAILEY, UNIVERSITY OF THE VIRGIN ISLANDS; HYE-JI KIM, PURDUE UNIVERSITY

Two to three gallons of water

can support as much as one

square foot of growing space.

LEDs that glow with a purple

mix of red and blue promote

growth and can provide more

hours of light than sunlight.

Leafy crops are easiest to grow

aquaponically and include

lettuce, herbs such as basil and

mint, and medical cannabis.

Purified water is recirculated

to the rearing tank.

Seedlings are moved

from nurseries to rafts

atop soil-free grow beds

up to 18 inches deep.

Plants immersed in

flowing, nutrient-rich

water can grow twice

as fast as land crops.

About 98 percent of

water, now free of toxic

ammonia, circulates back

45 6to fish-rearing tanks.

SMALL-FOOTPRINT FARMING

Commercial aquaponic systems can yield

up to 12 times as much produce per square

foot as crops grown in soil—a boon to

areas with limited freshwater and arable

land. Current research focuses on reducing

energy use and incorporating automation.