Irrigation is one of the most water-intensive agricultural activities in the world, which has been increasing over time. Choosing an optimal irrigation management plan depends on having available data in the monitoring field. A smart agriculture system gathers data from several sources; however, the data are not guaranteed to be free of discrepant values (i.e., outliers), which can damage the precision of irrigation management. Furthermore, data from different sources must fit into the same temporal window required for irrigation management and the data preprocessing must be dynamic and automatic to benefit users of the irrigation management plan. In this paper, we propose the Smart&Green framework to offer services for smart irrigation, such as data monitoring, preprocessing, fusion, synchronization, storage, and irrigation management enriched by the prediction of soil moisture. Outlier removal techniques allow for more precise irrigation management. For fields without soil moisture sensors, the prediction model estimates the matric potential using weather, crop, and irrigation information. We apply the predicted matric potential approach to the Van Genutchen model to determine the moisture used in an irrigation management scheme. We can save, on average, between 56.4% and 90% of the irrigation water needed by applying the Zscore, MZscore and Chauvenet outlier removal techniques to the predicted data.

Biochar is a solid material formed during biomass thermochemical decomposition processes. This organic compound has particular properties that may cause effects on soils depending on its feedstock and processing conditions. Thus, the characteristics and purpose of use of this material must be recognized prior to its use. Two types of biochar, derived from different wood sources, were compared, one from caatinga biome species and another from cashew trees. Two species from caatinga biome were used, jurema-preta (Mimosa tenuiflora Willd. Poir.), and marmeleiro (Croton sonderianus Müll. Arg.). This study aimed to identify the best biochar material regionally available to increase water-holding capacity in the soil, based on laboratory tests and microstructural porosity evaluation. Biochar from Caatinga wood demonstrated an improved water-holding capacity if compared to cashew wood biochar. The particle diameters of 2 and 4 mm showed the highest levels, which were 2,268 g.g^-1 for caatinga wood and 0.574 g.g^-1 for cashew wood biochars, respectively. While the smaller quantities of macropores and a larger number of micropores (smaller radius) could explain the higher water-holding capacity for biochar from caatinga wood, the thick lignified cell walls of biochar from cashew wood support the idea of a hydrophobic effect contributing to water lower holding capacity.