Esta investigación a largo plazo se está llevando a cabo en tierras degradadas de baja fertilidad en los trópicos húmedos de la Amazonía peruana. El objetivo es recuperar tierras degradadas para una agricultura sostenible que se vio afectada por la agricultura migratoria y los pastos sobrepastoreados. Los ensayos de recuperación en tres fincas son cultivos de cobertura fertilizados con la leguminosa Centrosema (Centrosema macrocarpum), y el establecimiento del prototipo de sistemas agroforestales se basa en a) árboles leñosos con Swietenia macrophylla, Guazuma crinita (GC), Calycophylum spruceanum (CS ) y Simarouba amara (SA), b) árboles frutales leñosos con Cedrelinga cateniformis, GC, SA, Inga edulis y Bactris gasipaes, y ac) sistema silvopastoril con Centrosema y árboles leñosos con GC, SA y CS.Los suelos degradados compactados se cubrieron con pasto degradado (Brachiaria ...

Internal magnetic states and changes in the texture of the magnetization in cobalt nanodisks have been studied using micromagnetic simulations under two different initial conditions: a nucleated Bloch type skyrmion placed at the center of the cobalt disk and displaced 32 nm from the center. Analysis of simulation results clearly demonstrates that variations in values of the anisotropy (Ku) and Dzyaloshinskii-Moriya interaction (DMI) constants have strong influence on the internal magnetic states and the energy terms of the cobalt nanodisk. Of interest is the nucleation and stability of magnetic skyrmions as a function of the DMI constant. Micromagnetic analysis suggest that the interplay between demagnetizing, exchange and Dzyaloshinskii-Moriya energies induces a diagram with different textures of the magnetization including the Bloch and Néel type skyrmions, incomplete skyrmion and sky...

An agroforestry system (SAF) is characterized by having a diversity of components, such as timber and non-timber forest species and crops, pastures, or a livestock production system. This diversity of components in the system reduces the intensity of diseases, e.g. foliar diseases. This study aimed to detect the fungal microorganisms associated with the leaf spots of plant species that are part of the agroforestry production systems of the Peruvian farmers from Yurimaguas and to determine the level of incidence of the leaf spots in the systems of agroforestry production. Different land cropping systems were implemented in the farms, such as palm (Bactris gasipaes) to produce palm hearts, cocoa (Theobroma cacao), and plantain (Mussa sp.). Also, silvopastoral systems with fast and slow growing timber species and cattle with pastures for grazing and reforestation in areas of secondary fores...