The bioactive molecule of this element, mono-silicic acid, continues to surprise and is the subject of an extensive literature in the HORTCOM theme Silicon in Agriculture.
It has been shown to be a useful addition in aquaculture and the farming of shrimps in brackish water and fish in fresh water. Fish-farming might seem out of place in this Blog but a significant number of modern glasshouse units are raising fish in the space under the benches on which plants are being grown and in nearby tanks and ponds, searching for new methods to exploit circular production economies. Contemporaneous introduction of silicic acid in irrigation systems for the plants in cultivation should also provide improvements in cultivation. It is well-known that diatoms in the plankton produce their exoskeletons using silicic acid. When additional silicic acid is added to the water creates a ‘bloom’ in diatoms (phytoplankton) and zooplankton and in those organisms that feed on them that in turn provides more food for shrimps and fish that grow much more rapidly. It is also known that shrimps feed exclusively on diatoms for the first three days of their life.
In experiments in India, the application of stabilized bioactive silicon (combined with other minerals in the product SILIYAK) over a period of just seven weeks, increased body weight of shrimps by 26% over the controls and the survival rate by 19%. In a trial in Bangladesh, the body weight of Carp in fresh-water lakes, increased by some 70% over the controls by applying almost the same silicon product (SILFISH). The benefit/cost ratio of using this product is claimed to be over 3:1. For further information on the product and trials, contact Rexil-Agro BV.
No list of Biostimulants for use in agriculture is complete without SILICON listed as a separate and major category, furthermore other listed products/categories frequently contain silicon. Presentation for Silicon Solutions Book.
By definition Biostimulants are effective only against abiotic (climatic) stresses, yet it is well-known that bioactive silicon also has a positive effect on biotic stresses (pests and diseases) through its activation of plant immune systems and deterrence of feeding insects. Italpollina have recently launched the scientifically reliable and informative website on Biostimulants to assist grower orientation to the mass of new products that are available, the numbers of which have been mushrooming in recent years in much the same way as Integrators for human health. See also the pdf diagram in English and the article: How Pure is Our Science (English).
Here are links to two recently published scientific papers on the positive effects of bioactive silicon in plant cultivation follow, but a the HORTCOM theme Silicon in Agriculture is essential background reading.
Silicon application in tomato cultivation alleviated low phosphorus-induced decreases in growth and physiological parameters. In particular it increased photosynthetic rate by 65.2% leasing to significant increases in yield. It also succeeded to increase the concentration of most essential elements in roots, leaves and stems. It remains a paradox that silicon is still not considered an essential element in plant growth and development. Silicon Compensates Phosphorus Deficit-Induced Growth Inhibition by Improving Photosynthetic Capacity, Antioxidant Potential, and Nutrient Homeostasis in Tomato. Agronomy 2019, 9, 733.
Silicon mediated stress involves various regulatory mechanisms such as photosynthesis, detoxification of harmful ROS’s (reactive oxygen species) and nutrient management (orchestration). The application of supplementation of Silicon improved physiology and yield of several important agricultural and horticultural crops growing under salt stress. Mechanisms of Silicon-Mediated Amelioration of Salt Stress in Plants. Plants 2019, 8, 307.
It should also be noted that the next edition, the 8th of the International Conference on Silicon in Agriculture (ICSA) held every three years will be held at Baton Rouge, LA, USA, 26-29th October 2020. Thr latest information will be posted by ISSAG (International Society for Silicon in Agriculture)..