The Effects of Sugar & Salt Water on Plants

...

Plants take in mineral salts and water through a process called osmosis. Salt and sugar in soil water can adversely effect plants. Plant life requires some mineral salts, but plants produce sugars through metabolism and do not require added sugar.

Plant Cell Osmosis

Osmosis is the diffusion of water across a membrane, Colorado State University explains. The movement across the membrane generates osmotic pressure. The membrane is permeable, which allows free movement of water, but not of the solute molecules or ions. Solute refers, in this case, to the sugar and salt to be dissolved in the water.

Movement Across the Membrane

Changing concentrations of solute molecules and ions at the surface of the membrane produce variable concentrations of water molecules on both sides of the membrane. Movement across the membrane occurs when water flows from the side with the lower solute concentration to the side with the higher solute concentration, CSU reports. If pure water existed on both sides of the membrane, the osmotic pressure difference would be zero.

Effect of Sugar

Plants' cell walls become swollen and rigid when the cells fill with water. In other words, the cells become turgid, or swollen and hard, when osmotic pressure builds in the cells. This action keeps the leaves of the plant from wilting and allows it to stand up in sunlight, biology teacher Nigel D. Purchon writes on his websute. Purchon adds that when a concentrated sugar solution is added, the cell walls shrink and pull apart from each other — and the plant wilts. Sugar lowers the osmotic potential of the water present in the soil, making less water available for the plant to take in from the soil.

Effect of Salt

Plants require some mineral salts for survival. Salt water in high concentration, however, dehydrates the plant. A high salt-solute concentration in the soil pulls water away from the plant cells, through osmosis, and deposits it into the soil. The Salinity Management Guide website reports that different plant species have differing tolerances for soil salt levels. Injury to the plant occurs when tolerance levels are reached or exceeded.

Visible Signs of Too Much Salt

The Salinity Management Guide reports that mild to moderate salt concentration shows growth stunting and smaller yield of flowers, fruits or vegetables. Signs of high salt concentration include yellowing and browning of leaves. At very high salt concentrations, the soil becomes hard and crusty and the plant will lose its leaves and may die.

REFERENCES & RESOURCES
Comments
PARTNER & LICENSEE OF THE LIVESTRONG FOUNDATION

Copyright © 2018 Leaf Group Ltd. Use of this web site constitutes acceptance of the LIVESTRONG.COM Terms of Use, Privacy Policy and Copyright Policy. The material appearing on LIVESTRONG.COM is for educational use only. It should not be used as a substitute for professional medical advice, diagnosis or treatment. LIVESTRONG is a registered trademark of the LIVESTRONG Foundation. The LIVESTRONG Foundation and LIVESTRONG.COM do not endorse any of the products or services that are advertised on the web site. Moreover, we do not select every advertiser or advertisement that appears on the web site-many of the advertisements are served by third party advertising companies.