| Besults are presented of mineral fertilizer trials witht Irish potato crop in the State of São Paulo. The experiments were conducted in the flat lands of the Paraíba River banks. In this region, potato plantings are usually made from May to October, a period with little rain, :nul practically free from flood. From October to April, when good weather conditions prevail, rice is almost the only crop grown. Iu other regions of the State, potato is planted in February or in August. Chemical analyses of an average sample of the soil revealed a high organic matter content, about seven fold higher total nitrogen content and a twelve fold higher total carbon content, as compared with those found in a soil sample taken from Capão Bonito, an important potato area in... |
