Dr Vanderlise Giongo1, Dr Monica Santana2, Dra Alessandra Salviano1, Dr Tony Cunha1
1Embrapa Semiarido, Petrolina, Brazil, 2Universidade Federal do Ceara, Fortaleza, Brazil
Dryland areas cover over 47% of the terrestrial land surface and are inhabited by nearly 38% of the world population. In the Brazilian semiarid, intensive irrigated agricultural systems extend over 1,171,159 ha leading to soil organic matter reduction, soil salinization, water scarcity and climate change. This work aimed to demonstrate the impact of land use change and how new multifunctional agroecosystems designs can improve soil carbon and mitigate the degradation process. We analyze the soil carbon stock up to 20 cm. The data came from two long term field experiment that consisted of two soil tillage systems (NT-no till and T- till) combined with three plant cover crops mixtures (PM1-75% leguminous + 25% grasses and oilseed species, PM2-25% leguminous + 75% grasses and oilseed species, and PM3 – spontaneous vegetation) with mango orchard and melon crop. The areas, originally under native, was cut down and converted to an agricultural system in 1972, and cultivated for 16 years with corn, common beans, and watermelons, under a conventional soil tillage system, followed by date palm for 20 years in mango orchard and more four year of fallow before start the experiment with melon crop. In this period, the soil carbon stock decreased by 0.31 Mg. ha-1.yr-1. Nine and five years after the establishment of the long-term fields experiments with Mango orchard and melon crop such as mains economic cultivated plant, respectively, we observed that soil carbon increase. Mango orchard agroecosystems improve 0.41 Mg C. ha-1.yr-1 while Melon crop agroecosystems improve 0.81 Mg C. ha-1 yr-1, during this time. Microenvironmental characteristics and aboveground phytomass distingue the addition carbon rate into the soil. Regardless of the type of plant mixture or soil tillage systems, the multifunctional agroecosystems can improve the organic matter.
Degree in Agronomic Engineering from the Federal University of Pelotas (1994), a master’s degree in Soil Science from the Federal University of Rio Grande do Sul (1997) and a PhD in Soil Science from the Federal University of Rio Grande do Sul (2002). I work in the area of Agronomy, with emphasis on soil chemistry, working mainly in the following subjects: aluminum, corn, soil, bioassays and silicon. She is currently a researcher at the Center for Agricultural Research in the Semi-Arid Tropics, in the area of Soil Management and Conservation, developing studies with inventory and dynamics of carbon flow and technologies for low carbon agriculture