AsianScientist (May 6, 2015) – Silicon (Si) is the second most abundant element of the earth’s crust after oxygen. It has long been neglected by ecologists, as it is not considered an essential nutrient for plants.
However, research of recent years has showed that it is beneficial for the growth of many plants, including important crops such as rice, wheat and barley. For instance, Si has been found to enhance the resistance against pests, pathogens and abiotic stresses such as salts, drought and storms. Silicon might thus play a crucial role in the development of ‘sustainable’ rice production systems with lower or zero input of harmful pesticides.
Researchers from the interdisciplinary LEGATO project on sustainable rice production look in more detail at the cycle of plant-available Si in contrasting regions of Vietnam and the Philippines to provide insights on the importance of this element on rice production.
The study, published in the journal Plant and Soil, investigated Si cycling and budgets on the farm level in the Laguna province of the Philippines. The data shows that irrigation water can provide a considerable amount of the Si that is taken up by plants. In rain water, the concentrations of Si were below the detection limit of the analytical method and was thus assumed not to be an important Si source for plants. Another major source of plant-available Si is the dissolution of solid soil particles.
In a subsequent study, the LEGATO researchers focused on the soil processes that determine the pool of plant-available Si during the growing period. Recent literature suggests that the recycling and decomposition of rice straw plays a crucial role for Si availability. The farmers should therefore recycle the straw completely.
However, this is not done by all of the farmers that were interviewed within the LEGATO project. Some of them remove part of the straw and use it as fertilizer on vegetable fields instead. Over the long-term, this could have negative effects on the Si supply to rice plants. Particularly, in regions where soils are strongly weathered and the Si availability is therefore very low (e.g. the LEGATO study sites in Vietnam), farmers should consider Si availability as a factor in the management of rice fields.
The article can be found at: Klotzbücher et al. (2015) Forms And Fluxes Of Potential Plant-available Silicon In Irrigated Lowland Rice Production (Laguna, the Philippines).
———
Source: Legato Project; Photo: Madeleine Deaton/Flickr/CC.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
