ABSTRACT Studies related to climate change and agricultural value chains have in common the growing concern on conserving water resources. Thus, the concept of the water footprint stands out, which measures the amount of water (in volume) necessary to produce a unit (in mass) of a given product. Among Brazilian agricultural activities, coffee farming emerges as one of the most important, even though the crop is sensitive to potential climatic changes, especially to the increase in temperature and periods of drought. An alternative to mitigate the effects of climate change is shade management, which is common in agroforestry systems. Therefore, the objective of this study was to evaluate the influence of shade management on the water footprint of coffee activity in the region of “Matas de Minas”. The water footprint was calculated for the field and product processing phase. Despite reducing the evapotranspiration of the coffee plant, shade management provided an increase in the water footprint, since it decreased the crop yield. The water footprint data obtained are expressive, with a calculated value of 13,862 m3 t-1 for full sun management and 16,895 m3 t-1 for shade management, in which both are the most recommended for the agricultural sector.

Abstract: The objective of this study was to evaluate the organic carbon (OC) distribution and inorganic phosphorus (P) fractions on different soil aggregates classes under forestry fragment of Atlantic Forest, pasture and agroforestry managed for a long period. Soil samples were collected at depths of 0.00-0.10, 0.10-0.20 and 0.20-0.60 m, and the aggregate stability analysis was performed at each depth. The OC and the inorganic P fractions (Pbic readily available, NaHCO3 0.5 mol L-1; PNa1 moderately available, NaOH 0.1 mol L-1; and PNa2 restricted availability, NaOH 0.5 mol L-1) were determined in the respective classes of soil aggregates 4-2, 2-1, 1-0.5, 0.5-0.25 mm. Soil under forestry fragment showed higher OC contents and regardless the land use, highest values of inorganic P were found in the aggregates > 1 mm. Forestry showed highest levels of Pbic, while agroforestry showed the highest levels of PNa1, and pasture had highest values of PNa2.

Abstract This study aimed to evaluate the effect of soil management on water, sediment and P losses in slope plots in east-central Illinois, USA. Field and laboratory experiments were conducted. The soil management studied were: tillage in contour (CT), tillage in downhill (DT), no-tillage (NT) and bare soil (BS). After collecting the field data, WEPP model was used to model the erosion process. The NT and BS management resulted in low (152.35 mm field; 28.51 mm laboratory) and high (315.25 mm field; 63.67 mm laboratory) water loss respectively. For soil losses, similar behavior was observed for NT (0.45 t ha-1 field; 0 t ha-1 laboratory) and BS (87.27 t ha-1 field; 0.86 t ha-1 laboratory) managements. In case of P losses, CT management resulted in the lowest loss (216.26 g ha-1) while high values were found in the BS management (1806.06 g ha-1). The modeled results obtained from WEPP model did not show a good agreement with the data collected at field overestimated and underestimated the soil and water losses. The enrichment rate of runoff with sediment was influenced by soil management practices and the DT (34.48 g L-1 min-1) management showed the high peak. The adoption of NT management in agriculture areas with high slope (32%) can be beneficial to reduce erosion process. The total removal of vegetation cover leaving the soil exposed, similar to the BS management and soil preparation along the slope (DT management) should be avoided.