[Sulphure direct and indirect application effect in onion and potato cultivation under field and greenhouse conditions] | Efecto de la aplicación directa e indirecta de azufre en los cultivos de cebolla y papa bajo condiciones de campo e invernadero

abonos npk allium cepa application rates azufre dose d'application engrais npk evaluation farmyard manure fertilisation fertilizer application field experimentation fumier greenhouses invernaderos npk fertilizers organic matter peru serre soil types solanum tuberosum soufre sulphur tipos de suelos type de sol