Effects of different management systems of the physical properties of a clay Yellow Latosol of the state of Amazonas

Abstract

A study to evaluate the influence of different management systems on the physical properties of a clay Yellow Latosol (Typic Acrorthox) grown to rubber-tree (Hevea spp.) was conducted at the Experiment Station of the Rubber and Oil Palm Research National Center, located in Manaus, State of Amazonas, Brazil. The experimental design was a randomized one with six treatments and three replications. The following treatments, were studied. 1. Tillage without vegetative cover I; 2. Tillage without vegetative cover II; 3. No-tillage with vegetative cover I:4. No-tillage without vegetative cover II; 5. No-tillage with vegetative cover, and: 6. Virgin Forest (check). The vegetative cover of treatments 3, 4 and 5 consisted of the legume kudzu tropical (Pueraria Phaseoloides). Due to the large proportion of mineral fractions smaller than 0.002 mm as well as to the high degreee of floculation, this soil presented a considerably high aggregate stability and, consequently, a low erodibility hazard. The vegetative cover was the most important variable since it was the one which produced the best soil tilth, Moreover, when associated to the no-tillage practice it was almost as good as the virgin forrest in improving and preserving the physical condition of the soil.