Balanço de energia, consumo hídrico e coeficiente de cultivo do trigo no sudeste brasileiro

Abstract

Energy balance, water consumption and crop coefficient of wheat in the southeastern Brazil. The wheat is one of the most important crop of the world, and the few one that Brazil is not self-sufficient, producing only 50% of domestic demand. Studies related crop growth and its mass and energy exchange with atmosphere may help to improve the crop planning and management. The objective here was to study on the energy balance and water use of wheat crop, take into account the canopy-atmosphere coupling approach in such study. To do so, an irrigated experiment was conducted in Piracicaba-SP, at the Escola Superior Luiz de Queiroz-ESALQ, sown on May of 2017. The results showed that the latent heat flux (LE), sensible heat (H) and soil heat (G) represented 81.17%, 14.13% and 4.7% of the net radiation (Rn). Cumulative evapotranspiration for the whole wheat crop was 301 mm, with na average daily evapotranspiration of 2.8 mm.d-1. The crop had a mean decoupling fator (Ω) for the cycle of 0.53, but varied with the phenological phases as: 0.68 (head development), 0.55 (flowering), 0.26 (grain formation) and 0.3 (maturation). The crop coefficient along the cycle was 0.58, 1.12, 1.46, 1.23, 1.32 and 0.73 for the respective phases establishment, tillering, head development, flowering, grain formation and maturation, with the average Kc for the cycle was 1.08. The values of Kc indicated a decrease when there was elevation of reference evapotranspiration (ETo). Thus, Kc values for different ETo intervals were: 1.09 (ETo ≤2); 1.34 (2 <ETo≤3); 1.25 (3 <ETo≤4); 0.77 (ETo> 4).

Effect of Silica Content on Cellular Structural and Hygroscopicity of Modified Cassava Starch Foam

“…Similar results were found in the literature, where the addition of kaolin (or composed of silicates) decreased the water absorption of foams. [ 29,35,54 ]…”

“…Similar results were found in the literature, where the addition of kaolin (or composed of silicates) decreased the water absorption of foams. [29,35,54] A moisture absorption analysis was also performed using the Peleg method. [42] And the constants K1 and K2 are shown in Peleg's constant K1 refers to the speed of moisture absorption, and according to the graph, the foam that presents the highest K1 was foam D-3%, which indicates that this sample was the one that presented the slowest absorption.…”