Wild potato grows on soils formed from weathering products in a cool, moderately humid climate of high mountain valleys of the Andes. His home-region of summer rains, with frequent mists and aligned relative to the change of temperature due to proximity to the sea. Accordingly, the potato has a low suction force: the great assimilative surface. It grows well in acidic soils, as the products of weathering of soils in places of origin were initially acidic. It’s a great need for potassium meets the same requirements of other plants in the sandy subsoil, such as buckwheat or lupines, and therefore too much soil liming effect on potato negatively. The further cultural potatoes in dry areas, the less favorable to him become the external environment. It is possible that the culture comes from the diploid potato species Solarium vernei wild as a result of higher natural polyploidization.
In many respects, the requirements of alfalfa to conditions of life are opposite requirements of potatoes. As well as wheat, barley, rye and corn, it belongs to the steppe plants, preferring arid regions, but on their drought tolerance, they are still mesophytic. Lucerne has a large mass of the root system and a large suction force. Its aerial parts are not too large, and small potatoes compared to the leaf surface protect it from strong evaporation. Alfalfa is well-
Growing in soil containing alkaline salts. Its high durability with respect to the presence of salts in the soil, also characteristic of some plants to the coast, such as sugar beet. In the humid cool climate of the steppe plant viability is reduced. The poor in lime or acid soils, it also grows poorly and is susceptible to disease. From the most demanding crops barley. He is very sensitive not only to damp and cold, especially in the period before the summer, but also to the acidity of the soil. With its low coefficient of evaporation it still can be cultivated as summer crops in areas where only 450-500 mm of rain falls. Rye also carries a severe drought. This is the first plant in the virgin lands, which is very undemanding for the content of nutrients in the soil and so can grow even on light soils with relatively little rainfall. Steppe vegetation with higher flow rates than in barley and rye, wheat is. As a plant rich in humus and loess soil salt, wheat needs at the time of strong growth in the abundance of water, and at maturity - the heat and dryness. Therefore, it grows best in warm temperate and subtropical zones. Here are grown and most of the corn, and most of the world production of corn provide the United States, Brazil