ASApedia/Agua Verde/en
The ASA approach focuses primarily on “green water” , which refers to infiltrated rainfall, stored as soil moisture and available for plant uptake (Falkenmark and Rockström, 2006). It is the water used by plants to produce productive and vegetative biomass that is stored in soil micropores. It is found in rainfall, soil moisture and plants and is a strategic input for agricultural production, especially rainfed agriculture which is completely dependent on this resource. [ 1 ]
Green water: challenges and opportunities
In Central America, 92% of basic food crops are produced using rainfed agriculture, which uses green water from the rain entirely, without the intervention of irrigation. [ 2 ] Currently, crop productivity in this type of agriculture in Central America is low compared to its potential. Green water is an opportunity to improve yields. [ 3 ]
The problem for small Central American farmers' production systems related to green water is the process of soil degradation, which means they lose their basic functions for storing it.
For this reason, the soil's capacity to retain water is under threat and exacerbated by the impacts of climate change and the canicula , which is the most serious climatic risk for rain-fed agriculture that depends on rain. It is a threat that grows as changes in climatic conditions increase in severity, duration and variability, endangering both the first and second crops of May. [ 4 ]
This is the strategic reason why it is necessary to manage green water, to promote the restoration of the water cycle in its underground phase, by improving the physical, chemical and biological properties of the soil, making it more stable and improving its capture for the use of plants and producing more biomass, under the agricultural approach of " managing the soil to manage water productivity ."
It is necessary to promote soil-restoring agriculture to improve water productivity, as healthy soil stores greater volumes of green water. When green water is absorbed by plants, it combines with CO2 and other elements to produce plant life and development, and returns to the atmosphere as vapor through transpiration after being used in the process of photosynthesis to produce crops. [ 5 ]
A major challenge for agriculture is that population growth requires more food production, and rainfed agriculture has great potential to reduce this yield gap by increasing water productivity on lands already under cultivation, with more efficient use of water. [ 6 ]
ASA objective to favor agriculture
The greatest gains for overall water productivity come from the ability to maximize rainwater harvesting through improved infiltration of rainwater and subsequently improved soil moisture retention (Molden et al., 2009). This is one of the ASA objectives to strengthen rainfed agriculture , with increased green water productivity, which gives production systems greater resilience and improves the living conditions of rural families.
Bibliographic references
- ↑ Catholic Relief Services (2014). Agricultural practices to improve water productivity. https://asa.crs.org/wp-content/uploads/2018/09/CRS-PRACTICES-MAY-ALTARES.pdf
- ↑ Beekman et al., 2014 Water to feed the land. Inter-American Institute for Cooperation on Agriculture (IICA), San José, Costa Rica.
- ↑ Water and Soil for Agriculture. (December 5, 2016). Welcome to the Green Water blog . https://asa.crs.org/2016/12/welcome-to-the-green-water-blog/#:~:text=Green%20Water%20represents%20agriculture%20worldwide.
- ↑ Soleil, M et al., 2023. Scaling water smart agriculture to improve the productivity and resilience of rainfed smallholder production systems in Mesoamerica. Catholic Relief Services, Baltimore, United States.
- ↑ Hicks, P. (December 5, 2023). Blue Water and Green Water . Water and Soil for Agriculture. https://asa.crs.org/2016/12/blue-water-and-green-water/
- ↑ Ibid (1).
