Movimentação Vertical Do íon Potássio Em Neossolos Quartzarênicos Sob Cultivo Com Cana-de-açúcar

The objective of this work was to determine the vertical movement of the potassium ion in the profile of Quartzipsamment Entisols cultivated with sugarcane. Two experiments were conducted in field conditions. The first one consisted of an assessment of ion movement in the soil profile, down to 1.80-m depth, for two years, in an area cultivated with sugarcane and in another one under cerrado. The second one consisted of the evaluation of ion movement to a depth of 1.00 m, under two water regimes: Natural and controlled. In the experiment under controlled conditions, evaluations were done with 0.5-m2 plots, delimited by galvanized sheets, receiving 80 kg ha-1 K2O followed by the addition of 1,200 mm of water. The area cropped with sugarcane showed greater soil organic matter content, greater pH, and, consequently, greater retention capacity of K+ in the superficial layers of the soil profile than the cerrado area. Moreover, in the area with sugarcane crop, the evaluation of K+ availability in the profile of the Quartzipsamment Entisol profile was affected by the adopted water regime (natural or controlled rainfall). Regardless of soil use, K+ moves rapidly through the soil profile.5191548155

Soil cover plants on water erosion control in the South of Minas Gerais

Water erosion is responsible for soil, water, carbon and nutrient losses, turning into the most important type of degradation of Brazilian soils. This study aimed to evaluate the influence of three cover plants under two tillage systems on water erosion control in an Argisol at south of Minas Gerais state, Brazil. The cover plants utilized in the study were pigeon pea, jack bean and millet, under contour seeding and downslope tillage. Experimental plots of 4 x 12 m, with 9% slope, under natural rainfall were used for the quantification of losses of soil, water, nutrients, and organic matter. One experimental plot was kept without plant cover (reference). Higher erosivity was observed in December and January, although a great quantity of erosive rainfall was detected during the whole raining period. Contour seeding provided a greater reduction of water erosion than downslope tillage, as expected. The jack bean under contour seeding revealed the lowest values of soil, water, nutrients and organic matter losses