Escoamento superficial de água em um argissolo com plantas de cobertura sob chuva natural

Abstract

The human activities have caused a great negative impact on the surface runoff of water in the soil. Aiming to minimize these effects, the cover crops started to exercise an important position on soil management. However, understand with more accuracy the factors that condition smaller surface runoff water volumes are fundamental to develop a strategical planning to the sustainable management of soil. Thus, this work aimed to evaluate if different cover crops presented differences on the surface runoff in natural rain events. The study was composed by six treatments: Naked soil (SD), Paspalum notatum (GP), Arachis pintoi cv Belomonte (AF), Lolium multiflorum (AZ), Avena strigosa + Raphanus sativus (AN) and Avena strigosa + Vicia villosa (AE) in a randomized block design (DBC) with 4 blocks, totalizing 24 experimental units. 23 natural rain events were evaluated. To determine the volume of water surface runoff were used collector gutters with pressure sensors connected in an Arduino Mega with wifi connection in an remote server. Also, were used umidity sensors connected in an datalogger and one automated pluviograph to mensure the soil umidity and the total volume of rain during the events. Furthermore, were collected samples of each treatment to evaluate the biomass production in differents times of development. The results showed who the perennial crops of GP and AF presented the higher biomass production. Between the annual crops, stand out the AE. In events below 10 mm, the surface runoff was negligible for all treatments. However, in the others, SD ever presented the higher volumes of surface runoff of water. In adittion, all of the other treatments presented acceptable runoff rates, especially AZ, GP and AF. Despite this, in high intensity rainfall, the runoff was higher in all treatments, but, with greater dimension in SD. Furthermore, closer the soils were to the saturation, higher were the volume of surface runoff. Finally, soils with higer biomass presented less surface runoff than naked soils, but, other factors will also affect the attainment of smaller volumes of surface runoff of water.