In the developed world, industrial agriculture based on large-scale monoculture has become the dominant system of modern farming, although there is growing support for sustainable agriculture. Modern agronomy, plant breeding, agrochemicals such as pesticides (which has increased since 1950 to 2.5 million tons annually worldwide), fertilizers, and technological improvements have sharply increased yields from cultivation, but at the same time have caused widespread ecological damages and negative human health effects.
Agriculture represents 70% of freshwater use worldwide: water management is needed in most regions of the world where rainfall is insufficient or variable. Essentially agriculture draws water from aquifers and underground water sources at an unsustainable rate.
Increasing pressure is being placed on water resources by industry and urban areas, meaning that water scarcity is increasing and agriculture is facing the challenge of producing more food for the world’s growing population with reduced water resources.
Even more, climate change has the potential to affect agriculture through changes in temperature, rainfall (timing and quantity), CO2, solar radiation and the interaction of these elements. Agriculture is among sectors most vulnerable to the impacts of climate change; water supply for example, will be critical to sustain agricultural production and provide the increase in food output required to sustain the world’s growing population.
The underwater system of agriculture could overlap the problematic issue of pesticides: the closed ecosystem created inside the biosphere is well preserved from the parasites attack. No use of pesticides means to have an ecological environment in strict contact with the seawater, thus avoiding any perturbation of the sea ecosystem.
Concerning fertilizers, actually a liquid product of natural origin is applied to different substrates or to the hydroponic system to supply one or more plant nutrients essential to the growth of plants.
Further investigations will be addressed to the possibility to produce fertilizers from algae found directly in the sea where the underwater farm will be installed. In this way a complete sustainability in the life cycle of growing plants would be attained, re-using the sea products as feed.
Improvements in water management for agriculture are one of key topic of Nemo’s Garden Project. Indeed, thanks to the difference of temperature between the air inside the biosphere and the seawater around the structure, the water at the bottom of the biosphere evaporates and easily condensates on the internal surfaces.
Since the underwater farm needs an external source of water only for the start-up of plants growing, our system could be useful for those locations far from the bodies of water available (i.e., seas, lakes, aquifers, etc.).
Any product that is difficult to grow in harsh environments would benefit from the alternative agriculture system proposed in the Nemo’s Garden Project. However, the limits of what can be grown are yet to be defined. Further researches will be addressed to understand the types of vegetables suitable for the underwater agriculture.