It has been shown that soil management under organic farming can enhance soil organic carbon, thereby mitigating atmospheric greenhouse gas increases, but until now quantitative evaluations based on long term experiments are scarce, especially under Mediterranean conditions. Changes in soil organic carbon (SOC) content were examined in response to organic management with cover crops in a Mediterranean citrus plantation using 21 years of survey data. Soil organic carbon increase was more apparent 5 years after a land management change suggesting that, for citrus plantations on Mediterranean conditions, studies should be longer than five years in duration. Soil organic carbon sequestration rate did not significantly change during the 21 years of observation, with values ranging from -1.10 Mg C ha-1 y-1 to 1.89 Mg C ha-1 y-1. After 21 years, 61 Mg CO2 ha-1 were sequestered in long-lived soil C pools. These findings demonstrate that organic management is an effective strategy to restore or increase SOC content in Mediterranean citrus systems.

Elevated soil loss and runoff rates can reduce soil fertility; therefore, soil erosion control strategies must be implemented at the hillslope and watershed scale when plantations are established and the soil is bare. In this research, we propose the use of the Vicia sativa Roth. to reduce the soil losses during the first year to control the peak of soil erosion after the plantation in tilled vineyards. To test its efficiency, rainfall simulation experiments were carried out with field surveys in The Casa Pago Gran, in the Eastern Iberian Peninsula. Our results demonstrate that soil properties (organic matter and soil bulk density) and soil erosion (soil loss, runoff and sediment concentration) were significantly different between the control plot (tilled) and with cover crops along with August 2016, 2017 and 2018 measurement periods, but not during January 2016, coinciding with the initial survey before the vetch sown. Runoff initiation was delayed in 3.7 times after 3 years (from 190 till 709 s). The runoff discharge was reduced by the Vicia sativa from 32.87 till 13.68%, the sediment concentration went down from 18.54 till 3.81 gr l⁻¹ and the soil erosion from 3.36 to 0.29 Mg ha⁻¹ year⁻¹. An increase in soil bulk density was registered but did not affect the runoff generation either the soil losses, that was reduced by the plant cover. We conclude that it is necessary to include soil erosion control measures such as the use of Vicia sativa to reduce soil erosion processes during the first stages of the vineyard plantations due to the soil quality improvements and the reduction in soil and water losses.

There is an urgent need to implement environmentally friendly agriculture management practices to achieve the Sustainable Goals for Development (SDGs) of the United Nations by 2030. Mediterranean agriculture is characterized by intense and millennia-old tillage management and as a consequence degraded soil. No-Tillage has been widely examined as a solution for soil degradation but No-Tillage relies more on the application of herbicides that reduce plant cover, which in turn enhances soil erosion. However, No-Tillage with weed cover should be researched to promote organic farming and sustainable agriculture. Therefore, we compare Tillage against No-Tillage using weed cover as an alternative strategy to reduce soil losses in persimmon plantations, both of them under organic farming management. To achieve these goals, two plots were established at “La Canyadeta” experimental station on 25-years old Persimmon plantations, which are managed with Tillage and No-Tillage for 3 years. A survey of the soil cover, soil properties, runoff generation and initial soil losses using rainfall simulation experiments at 55 mm h⁻¹ in 0.25 m² plot was carried out. Soils under Tillage are bare (96.7%) in comparison to the No-Tillage (16.17% bare soil), with similar organic matter (1.71 vs. 1.88%) and with lower bulk densities (1.23 vs. 1.37 g cm³). Tillage induces faster ponding (60 vs. 92 s), runoff (90 vs. 320 s) and runoff outlet (200 vs. 70 s). The runoff discharge was 5.57 times higher in the Tillage plots, 8.64 for sediment concentration and 48.4 for soil losses. We conclude that No-tillage shifted the fate of the tilled field after 3 years with the use of weeds as a soil cover conservation strategy. This immediate effect of No-Tillage under organic farming conditions is very promising to achieve the SDGs.

Due to the reduction in the prices of oranges on the market and social changes such as the ageing of the population, traditional orange plantation abandonment in the Mediterranean is taking place. Previous research on land abandonment impact on soil and water resources has focused on rainfed agriculture abandonment, but there is no research on irrigated land abandonment. In the Valencia Region—the largest producer of oranges in Europe—abandonment is resulting in a quick vegetation recovery and changes in soil properties, and then in water erosion. Therefore, we performed rainfall simulation experiments (0.28 m²; 38.8 mm h⁻¹) to determine the soil losses in naveline orange plantations with different ages of abandonment (1, 2, 3, 5, 7 and 10 years of abandonment) which will allow for an understanding of the temporal changes in soil and water losses after abandonment. Moreover, these results were also compared with an active plantation (0). The results show that the soils of the active orange plantations have higher runoff discharges and higher erosion rates due to the use of herbicides than the plots after abandonment. Once the soil is abandoned for one year, the plant recovery reaches 33% of the cover and the erosion rate drops one order of magnitude. This is related to the delay in the runoff generation and the increase in infiltration rates. After 2, 3, 5, 7 and 10 years, the soil reduced bulk density, increase in organic matter, plant cover, and soil erosion rates were found negligible. We conclude that the abandonment of orange plantations reduces soil and water losses and can serve as a nature-based solution to restore the soil services, goods, and resources. The reduction in the soil losses was exponential (from 607.4 g m⁻² in the active plot to 7.1 g m⁻² in the 10-year abandoned one) but the water losses were linear (from 77.2 in active plantations till 12.8% in the 10-year abandoned ones).