US 9,807,949 B2
Root environment control system and method
John W. Hamlin, Port Angeles, WA (US)
Filed by John W. Hamlin, Port Angeles, WA (US)
Filed on Aug. 15, 2014, as Appl. No. 14/461,010.
Prior Publication US 2016/0044879 A1, Feb. 18, 2016
Int. Cl. A01G 31/00 (2006.01); A01G 9/02 (2006.01); A01G 31/02 (2006.01); A01G 27/00 (2006.01)
CPC A01G 31/02 (2013.01) [A01G 27/003 (2013.01); Y02P 60/216 (2015.11)] 15 Claims
OG exemplary drawing
 
1. A plant propagation apparatus for control of atmosphere requirements of roots of plants having at least one plant root system disposed in a root zone Z-2 connected to at least one stem supporting leaves disposed in a separate zone Z-1 for enhanced growth of said plants in an enhanced CO2 atmosphere enclosure said apparatus preventing infiltration of CO2 from zone Z-1 into root zone Z-2 by the combination of a CO2 impervious sealing membrane and maintaining positive pressure of O2 in said zone Z-1, comprising:
a) means for retaining said plant root system in said (a) plant root zone Z-2 comprising a cylindrical container having a top and bottom and including a sight glass tube connected adjacent said container bottom, said sight glass tube configured to provide an indication of a level of nutrient solution in said means for retaining said plant root system;
b) rooting media for support of plant roots disposed in root zone Z-2, said media having a property of maintaining said plant roots moist;
c) an aqueous nutrient supply system connected to said means for retaining said plant root system configured to supply aqueous nutrient solution to roots of a plant in said rooting medium in fill and flush cycles, disposed to introduce nutrient solution adjacent the bottom of said means for retaining said plant root system in said root zone Z-2 said media maintaining said plant root system moist during flush portions of said nutrient supply;
d) a separate gaseous oxygen-overpressure supply system connected to said means for retaining said plant root system in said plant root zone Z-2 configured to supply an overpressure of gaseous oxygen selected from air, O2 and O2-supplemented air to roots of a plant in said rooting medium in said root zone Z-2, and said gas supply introduces oxygenated gas adjacent the bottom of said root zone Z-2 via said sight glass tube, said container having no gaseous oxygen exhaust and said rooting media having a property of porosity that permits O2 to permeate to plant roots retained in said media;
e) a CO2-imperveous, flexible vinyl or neoprene sealing membrane disposed in association with said means for retaining said plant root system and disposed above said rooting medium at the top of said plant root retaining cylindrical container isolating said zones Z-1 and Z-2 from each other, said membrane being slit radially from a central point to permit the stem of a plant to project up from zone Z-2 into zone Z-1, said slits permitting stem enlargement without girdling yet effectively sealing off the root zone Z-2 from the stem/leaf zone Z-1;
f) said sealing membrane in combination with said gaseous oxygen overpressure supply system produces differential control of atmospheres in said zones by substantially gases-isolating the stem and leaves of said plant in said zone Z-1, from said plant root zone Z-2, said membrane maintaining differential atmospheres of high CO2 in zone Z-1 and an overpressure of oxygen in zone Z-2 relative to the pressure of CO2 in zone Z-1 and said gaseous oxygen overpressure supply system prevents infiltration of CO2 from stem/leaf zone Z-1 into the root zone Z-2 to prevent root poisoning by said CO2 from said zone Z-1;
g) at least one controller for preselected control of: i) an amount of nutrient solution supplied to said root zone Z-2; ii) a rate of supply of said nutrient solution to said root zone Z-2; iii) a schedule of supply of nutrient solution to said root zone Z-2; iv) an amount of supply of said oxygenated gas to said root zone Z-2 to maintain said oxygen overpressure; v) a rate of supply of said oxygenated gas to said root zone Z-2 to maintain said oxygen overpressure; and vi) said controller including a schedule of supply of said oxygenated gas to said root zone Z-2 to maintain said oxygen overpressure; said controller maintaining a repeating cycle of fill and flush of said plant root system container, and during flush said controller maintaining said oxygenated gas amount of supply and rate of supply sufficient to prevent infiltration of CO2 by negative pressure in said root system container while said roots remain moist in said media during flush portion of said cycle; and
h) thereby to improve plant growth and increase plant material harvest yield.