By Taylor Moore, Intern for Director Laura Thompson (All positions and opinions are that of Taylor Moore and her research conducted)
Nutrients, mainly nitrogen and phosphorus, come from natural (rocks, soil) and human (poultry litter, sewage sludge, manure) components. Human-related reasons provoke more nutrient pollution than rocks and soils do; this is especially true in coastal communities as there’s a huge human population. When farmers use these different types of animal waste as fertilizers, the inappropriate disposal of them contributes to about one-quarter of nutrient pollution in the Chesapeake Bay. Severe rain favors an overabundance of nutrients and sediment runoff firstly impacting our streams/rain which later ruins reservoirs such as the Chesapeake Bay. The excessive amount of nitrogen and phosphorus increases the algae population which obstructs light levels and thus inhibits photosynthesis. Light is needed to start photosynthesis whose end product is ATP (energy) and oxygen. If there’s no ATP and if there’s no oxygen then there’s no life. Thus, plants such as algae and seagrass will die and this will endanger the existence of all aquatic animals (blue crabs, oysters, striped bass, etc;.). Animal waste that is used at an industrial level is best recommended to be converted into biofuel (waste to energy). Also, sludge is not a competent method to fertilize as it takes too long for microbes to decompose and release nutrients necessary for plant growth. Therefore, it should be avoided.
Environmental stressors such as high concentration of NaCl (salt) results in water loss thus limiting the germination and growth of coastal plant species. Germination refers to when a seed breaks out of dormancy and starts to sprout. The scientific processes of osmosis and tonicity explore why water retention is weak. Osmosis is the diffusion of free water and tonicity determines whether a cell will lose or gain water. When an outside solution has a high number of solutes (NaCl) it has a low number of free water. In our case, the outside solution is salty soil. This is a hypertonic solution; when a cell (in this case a seed) is placed inside a hypertonic solution, water diffuses out of the cell.
As a result, the natural function of plants is changed under NaCl stress; however, depending on the species, it is possible that plants adapt to this type of stress. But it’s not guaranteed. As a mitigation strategy, farmers can use soil amendments like gypsum, sulfuric acid, sulfur, or anything nitrogen-based (Nitrol).
References
Amirjani, M. R. (2010). Effect of salinity stress on growth, mineral composition, proline content, antioxidant enzymes of soybean. American Journal of Plant Physiology, 5(6), 350–360. https://doi.org/10.3923/ajpp.2010.350.360
Andrews, E., Chope, K., Cosgrove John., Elias, A., & Goodall, J. (2021) The impact of climate change on Virginia’s coastal areas.
https://scholarship.law.wm.edu/cgi/viewcontent.cgi?article=3083&context=facpubs
Duffy, E. (October 8). Vanishing and emerging ecosystems of Coastal
Virginia: climate change impacts and adaptation. Virginia Institute of Marine Science.
https://www.vims.edu/research/units/legacy/icccr/_docs/coastal_ecosystems.pdf
Land, L. (2012). Chesapeake Bay nutrient pollution: Contribution from the land application
of sewage sludge in Virginia. Marine Pollution Bulletin. 64. 2305-2308.
Nivas, D., Gaikwad, D., Chavan., P. (2011). Physiological responses of two Morinda species under saline conditions. American Journal of Plant Physiology.