"Agriculture on Mars"@en . "A daunting gauntlet of problems would need to be resolved to establish an agriculture on Mars capable of sustaining a permanent human colony. In the minimum, plants need air, soil, water, and nutrients, all of which exist on Mars. The problems, then are in making the elemental needs of plant life available to plants that humans choose to grow. In the presence of all the needed material and science needed to achieve the goal, the major impediment that remains is the collective barrier of cost, effort, and timescale required to achieve it."@en . "A daunting gauntlet of problems would need to be resolved to establish an agriculture on Mars capable of sustaining a permanent human colony. In the minimum, plants need air, soil, water, and nutrients, all of which exist on Mars. The problems, then are in making the elemental needs of plant life available to plants that humans choose to grow. In the presence of all the needed material and science needed to achieve the goal, the major impediment that remains is the collective barrier of cost, effort, and timescale required to achieve it."@en . .