Sustainable multifunctional agroecosystems for irrigated melon in the Brazilian semi-arid region

"We hypothesized that change of tillage and use of plant mixtures as cover crops will improve SOC stock in dryland irrigated agriculture. Eventually, this could even exceed the equilibrium SOC found under natural dryland forest depending on soil disturbance, extent of soil cover and plant diversity, determining net biomass C input of the respective agroecosystem" The treatments consisted of two soil tillage systems, no-tillage (NT) and conventional tillage (CT), combined with three mixtures of cover crops [75% leguminous species + 25% grass and oilseed species (PM1), 25% leguminous species + 75% grass and oilseed species (PM2) and spontaneous vegetation (SV)]. The mixtures of cover crops were grown before the melon. "The plots were set up with 10 m length and 10 m width. In this area, 198 melon seedlings are transplanted annually at spacing of 2.0 m x 0.3 m. The seeds of the mixtures of cover crops are sown annually in July, in furrows with spacing of 0.5 m. Approximately 70 days after sowing, the plants are cut 5 cm above the soil surface. In plots without soil management, the phytomass is deposited on the surface by cutting with manual mower and, in plots with soil management, the phytomass is incorporated to 20 cm depth through plowing and harrowing. " four 0-5; 5-10; 10-20; 20-40; 40-60; 60-80; 80-100 cm TEIXEIRA, P. C. et al. Manual de métodos de análise de solos. 3 ed. Brasília, DF: Embrapa, 2017, 573 p "The total C contents were obtained by dry combustion using an elemental analyzer (LECO, model TRUSPEC CN). 0-5; 5-10; 10-20; 20-40; 40-60; 60-80; 80-100 cm" soil density Sandy loam mycorrhizas