High carbon dioxide concentration (CO2) in the atmosphere It is a double threat as it has effects on food safety And in global climate emergency. According to the conclusion of an international research team intervened by the Catalonia Center for Ecological Research and Forestry Practices (CREAF), high concentration of CO2 It reduces the availability of phosphorus in the soil where it grows in the atmosphere by more than 20%. rice. Phosphorus is an essential fertilizing mineral for a fertile soil..
This is the result of two experiments where, for the first time, rice fields were studied under conditions of high carbon dioxide. The research was published in the journal nature geology and experts from Australia, Spain, Canada, the USA, France and China.
The article predicts the risk of a massive reduction in rice yield, a situation that puts them in adverse conditions, especially in low-income countries and Widening economic inequality due to CO emissions2 and effects on geochemical processes.
The results show that 55% of large paddy fields in China and India will be at increased risk of yield reduction due to phosphorus deficiency.. Relatively, low-income countries (other than China and India, especially those located in Southeast Asia, Central America, South America, Africa and the Middle East) will experience more critical situations. 70% of paddy fields will be at higher risk of harvest compared to 52% in high- and middle-income countries.
The study revealed a paradox: although atmospheric CO2 is the main source of carbon for crops, its high concentration in the atmosphere limits the availability of phosphorus fertilizer in the soil in the long run.
This mineral is essential for the metabolism and growth of plants in agricultural soils. As described by CREAF and CSIC researcher Josep Peñuelas, “Plants benefit from the short-term fertilizing effect of the high CO2 concentration in the atmosphere. However, In the long run, rice crops no longer have phosphorus and the soil becomes poorer, so plant growth is affected.”.
As a result, this jeopardizes food security in the context of world population growth, where rice plays an important role.
A global challenge
Phosphorus fertilizer is unevenly distributed around the world and is made from a non-renewable resource, rock phosphate. 70% of its reserves are in Morocco and Western Sahara. and many countries depend on imports to dispose of them. As such, its sustained deficit may result in limited agricultural yields in certain parts of the world. In addition, the situation may worsen in the future, given the continued rise in atmospheric CO2 levels limiting the availability of phosphorus.
status one international sociopolitical challenge for access to this mineral with fertilizing capacity. “The difficulty of fertilizing farmland with phosphorus supplements in countries with lower purchasing power is evident and alarming,” says researcher Josep Peñuelas. In fact, during the 2007-2008 world food crisis, the price of phosphate rock and fertilizers rose 400% in 14 months, indicative of the strong socioeconomic instability associated with phosphorus. This price increase was also experienced in 2022.
Alternatively, the scientific team recommends: Planning of international phosphorus management strategies is urgent Thinking about future global changes.
Intensive fertilization, a questioned alternative
Intensively apply fertilizer to agricultural soils According to scientists, compensating for its long-term decline seems like an ideal alternative, but it has consequences that should be avoided.
On the one hand, over-fertilization of arable land with phosphorus to maximize production It is generally concentrated in countries with high purchasing power and who can afford it.mainly from Europe, North America and some from Southeast Asia.
On the other hand, Phosphorus accumulated in the soil is lost through rainwater runoff, erosion and leaching. (loss of water-soluble nutrients). Also, an excess of this mineral in river and sea waters is the main cause of harmful algae growth, fish death in estuaries and coastal waters, and dead zones known in science as eutrophication.
Two scientific experiments were carried out with rice for the first time in 15 and 9 year periods. The FACE (Free Air CO2 Enrichment) technology, most widely used by science, has been applied to raise the atmospheric carbon dioxide concentration and to study the responses of the biosphere. FACE is neither cheap nor easy to maintain, so experiments applying it for more than a decade are rare and extremely unique worldwide.
Reference work: https://www.nature.com/articles/s41561-022-01105-y
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