This is a field test report about potassium polyacrylate for lettuce in Japan.
Field Test Condition
PLANTS:Loose leaf lettuce “Green Wave” by Takii Seeds. It described to be good for sowing up to late September.
WATERING:Basically no watering during the winter season, until March.
WATER RETAINER AGENT:SAP From Pack Rain (Potassium Polyacrylate Type)
SOIL:Fine grain.Mixing several soils is to minimize possible influences from a particular soil.
CONTAINER:Black plastic containers No.9 (capacity:13.5 liters) with large and many drainage holes in the bottom.
Tip:Don’t to let the soil leak off the drainage holes,a square plastic mesh for drainage holes is laid on the bottom of each pot.
1.Mix the soils evenly.
2.Deal the mix obtained on 3 pots,about up to 1cm below to the rim(hence the soil amount
is assumed to be 13.5 liters, same as the pot capacity).
3.Put the SAP at the contents of 0%,0.6%,1.2%(the recommended dosage by SOCO is 1.25%). Macerate the soil with the SAP added in.
4.Press the surface soil with palms to settle it.
5.Sow loose leaf lettuce seeds:20 seeds/pot.
1.Nov.9, 2015 Preparations completed.
2.Nov.15, 2015 Plants have begun sprouting.
1.2% SAP/13.5 liters loose leaf lettuce, 0.6% SAP/13.5 liters loose leaf lettuce, 0% SAP/13.5 liters loose leaf lettuce as follows:
3.Mar.13,2016 Have a result.
0.6% and 1.20% looked well perceivably larger than 0%.
Between 0.6% and 1.2%, 0.6% seemed to cover more area of the surface of the pot soil.
The growth of the roots showed much more difference.When pulling off lettuces, it was not so difficult to plug the whole roots in the pot of 0%.But in the pots of 0.6% and 1.2%, especially 1.2%,the roots were deep and large you need to hold the soil right below the 1.2% SAP/13.5 liters
The growth of the roots showed much more difference.When pulling off lettuces, it was not so difficult to plug the whole roots in the pot of 0%.But in the pots of 0.6% and 1.2%, especially 1.2%,the roots were deep and large you need to hold the soil right below the leaves.
The roots of a lettuce in the pot for 1.2% showed it is utilizing the moisture from SAP.
After used SAP,the germination rate is 18/20 seeds, around 90%.
From figures as follows,SAP mixture ratios and the corresponding average unit weights of lettuces seem to indicate a proportional relation between the growth of lettuces and SAP dosage.
|SAP mixture ratios (in terms of soil weight)||1. 2%||0. 6%||0%|
|Average weights of one specimen (gram)||15. 1||11. 4||9.2|
1.The lettuces in 1.2% SAP pot have increased by 64.13% in yield.
2.The results also show super absorbent polymer strong prevented shortage of water and the subsequent stomatal closures in the day time,enabling the plants to take in CO2 from stomata to perform photosynthesis.