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Soil health and function is one of the most important components for sustainable management of woody orchards. Intensive use of machinery and tillage creates heavy pressure on agroecosystems by altering the soil physicochemical and biological characteristics. In this study we aimed to assess the changes in soil physicochemical properties and the soil bacterial community structure, as well as the main drivers involved in shifts in the microbial community following 10 years implementing reduced tillage and reduced tillage plus green manure in a rainfed Mediterranean almond orchard. The treatments were: i) conventional tillage (CT); ii) reduced tillage (RT); and iii) reduced tillage and diversification with Avena sativa and Vicia sativa (RTD). After ten years, the results showed that the different managements had no significant effect on almond yields. RTD significantly increased total organic carbon (TOC), with an average content of 19.5 g kg−1 compared to 17.1 g kg−1 in CT. RTD also contributed to an increase in the fraction of soil macro-aggregates. Both RT and RTD significantly increased soil total nitrogen (NT) and particulate organic carbon (POC). However, other physical and chemical variables such as exchangeable Ca, Mg and K, bioavailable Fe, Cu, Zn and Mn, cation exchange capacity, bulk density, wilting point and field capacity were not significantly affected by the management. The bacterial community significantly changed with management: RTD showed a higher relative abundance of the family Solirubrobacteraceae and the genera Streptomyces and Solirubrobacter. The bacterial community structure was explained by changes in TOC, POC, pH, and NT values. Thus, a combination of reduced tillage and green manure could represent an appropriate sustainable management for rainfed almond orchards in very fragile environmental conditions, due to an increase in soil organic matter, total nitrogen, and the higher presence of beneficial bacteria related to soil productivity

Soils provide key ecosystem services and are crucial to combat climate change. Agriculture provides important ecosystem services but also causes negative environmental effects depending on agricultural management. In this regard, crop diversification is a promising sustainable land management strategy to combat soil erosion and degradation, mitigate climate change and ensure food security. Here, we assess the combined short-term effects of crop diversification and no tillage on several key soil physico-chemical parameters related to soil functioning as well as on crop yields in a rainfed almond (Prunus dulcis Mill.) orchard under semiarid Mediterranean conditions. Almond trees were inter-cropped with Capparis spinosa L. (caper) or Thymus hyemalis Lange (winter thyme) and compared with the almond monocrop system. The experimental design consisted of three plots in a randomized-block design, with three replicates for each crop management treatment (almond monocrop, almond inter-cropped with caper, and almond inter-cropped with winter thyme). Along with crop yields, the combined effects of crop diversification and no tillage on a range of soil quality and health indicators including soil physical (bulk density, aggregate stability, water retention and availability) and chemical (total and particulate organic carbon and nitrogen, ammonium and nitrate content, available macro- and micro-nutrients) properties were monitored in the topsoil and subsoil (at 0–10 and 10–30 cm depth, respectively) one and three years from establishment

The implementation of alley cropping in orchards has been suggested as a sustainable strategy to increase farmer revenues by crop diversification, enhance soil organic matter (SOM) and fertility, water retention, overall biodiversity, and contribute to climate change mitigation. Thus, the objective of this study was to assess if alley cropping with annual crops can contribute to i) mitigate soil greenhouse gas (GHG) emissions, ii) enhance C sequestration in a semiarid Mediterranean irrigated citrus orchard, and iii) increase land productivity. For this, two different treatments were established: i) conventional mandarin monoculture (MC) with no alley cropping; and ii) mandarin diversified with alley cropping of barley/vetch and fava bean (DIV). Measurements of soil CO2 and N2O emissions were periodically performed (every 7–20 days) during two years. Soil CO2 emission rates followed the soil moisture trend, and showed no significant differences between treatments. As an average, soil CO2 emission rates were 147 mg m-2 h-1 in MC and 196 mg m-2 h-1 in DIV. Soil N2O emission rates were not correlated to soil moisture nor temperature, and showed average values of 0.026 mg m-2 h-1 in MC and − 0.002 mg m-2 h-1 in DIV. Alley cropping did not contribute to significantly increase soil organic C and total nitrogen in two years’ time. With regard to production, mandarin yield showed no significant differences between treatments, but alley crops contributed to complementary commodities to the main cash crop, increasing overall land productivity. Thus, alley cropping in irrigated Mediterranean orchards has no significant effect on soil C sequestration and GHG emissions at short-term, with increased land productivity owing to new commodities grown in the alleys. These results confirm that under semiarid Mediterranean climate, long periods are needed to efficiently assess soil C sequestration potential of sustainable practices in orchards.

Crop diversification is a promising strategy to mitigate climate change through soil carbon sequestration while ensuring soil fertility maintenance and food security. Here, we assess the impact of different inter-cropping practices on soil organic carbon (SOC) and nitrogen (N) storage and stabilization under rainfed and irrigated semiarid conditions. Under rainfed conditions, an almond (Prunus dulcis Mill.) monocrop was compared with an almond inter-cropped with caper (Capparis spinosa) or with winter thyme (Thymus hyemalis). Under irrigated conditions, a mandarin (Citrus reticulata Blanco) monocrop was compared with a mandarin inter-cropped with an annual crop rotation (including Hordeum vulgare, Vicia sativa and Vicia faba) or with a triennial crop rotation (including Vicia faba, Portulaca oleracea and Vigna unguiculata L.). The SOC and N stocks, SOC mineralization rates, water-stable aggregates and associated OC and N contents were estimated at 0–10 and 10–30 cm depth in each monocrop and inter-cropping system after three years. Contrasting effects of inter-cropping on SOC and N stabilization were found in the rainfed and irrigated systems. The combination of inter-cropping and no tillage did not affect the SOC stocks or mineralization rates at any soil depth in the rainfed system, while it significantly increased the OC and N contents within the large macro-aggregates in the subsoil. Compared to the irrigated mandarin monocrop, the mandarins inter-cropped with the annual crop rotation showed a significant increase of 10% and 18% in the topsoil and subsoil N stocks, respectively, while the SOC mineralization rates were reduced by 30% at both soil depths. On the contrary, the topsoil SOC stock in the mandarins inter-cropped with the triennial crop rotation were reduced by 38% compared to the monocrop. Significant reductions ranging between 24% and 66% were also observed in the OC and N contents associated to the macro- and micro-aggregates in the topsoil and subso

The growth of legumes, reduced tillage and addition of crop residues can be regarded as a good alternative in intercropping systems to increase soil organic matter, soil fertility and biodiversity while enhancing crop production and reducing the use of fertilizers. Despite the potential benefits, there is still a research gap about using the combination of cowpea and melon in intercropping to increase productivity and reduce external inputs. Thus, the aims of this study were to: i) assess if crop yield, crop quality and soil physicochemical properties can be improved by intercropping systems between melon (Cucumis melo L.) and cowpea (Vigna unguiculata (L.) Walp.) with reduced tillage and addition of crop residues, compared with a melon monoculture with intensive tillage and removal of crop residues, all grown under organic management; and ii) evaluated if cowpea grown as intercrop with fertilization reduced by 30% in the diversified plots can partially replace the use of fertilizers with no negative effects on total crop production. In this study we compared over three crop cycles monocrops with three different melon-cowpea intercropping patterns: mixed intercropping, row intercropping 1:1 (melon:cowpea) and row intercropping 2:1 (melon:cowpea). Our results, presented in this study, showed that intercropping systems, regardless of the pattern, kept soil organic C levels, while it significantly decreased in melon monoculture. Intercropping also significantly increased soil total N, available P and exchangeable K (0.13%, 62 mg·kg-1 and 387 mg·kg-1, respectively), compared to the melon monocrop (0.11%, 25 mg·kg-1 and 306 mg·kg-1). Total crop production was significantly higher under diversified systems, with land equivalent ratios > 1. Hence, the introduction of cowpea associated with melon, combined with reduced tillage and the incorporation of crop residues could be considered as a feasible strategy for sustainable agriculture, with environmental gains and economic

Intercropping can favour the yield of the main crop. However, because of the potential competition among woody crops, this system is rarely used by farmers. To increase knowledge about the intercropping system, we have explored three different combinations of alley cropping in rainfed olive groves compared to conventional management (CP): (i) Crocus sativus (D-S); (ii) Vicia sativa/Avena sativa in annual rotation (D-O); and (iii) Lavandula x intermedia (D-L). Different soil chemical properties were analyzed to evaluate the effects of alley cropping, while 16S rRNA amplification and enzymatic activities were determined to study the changes that occurred in soil microbial communities and activity. In addition, the influence of intercropping on the potential functionality of the soil microbial community was measured

Agricultural intensification is a highly specialized agri-food system that has contributed to raising food production worldwide due to progress in agricultural machinery and technologies, the use of improved cultivars, and external inputs such as fertilizers, irrigation, and pesticides [...]

Sustainable agriculture has been identified as key to achieving the 2030 Agenda for the Sustainable Development Goals, which aims to end poverty and hunger and address climate change while maintaining natural resources. Soil organic carbon (SOC) sequestration is a key soil function for ecosystem services, and storing carbon (C) in soil by changing traditional management practices can represent an important step toward the development of more sustainable agricultural systems in Europe. Within the European project Diverfarming, the process-based ecosystem model ECOSSE was modified and evaluated in four long-term experiments (>8 years) to assess the impact of crop diversification and agricultural management in SOC dynamics. ECOSSE was able to simulate SOC under dry conditions in Mediterranean regions in Spain and Italy. In the site of Murcia, Spain, the addition of manure and cover crop in the diversified systems produced an increase of SOC in 9 years, when compared with the conventional management (16% measured increase, 32% simulated increase). The effect of tillage management on SOC stock in dry soil, in Foggia, Italy and Huesca, Spain, was also modeled, and a positive impact on SOC was predicted when no tillage was practiced. Finally, ECOSSE was used to understand the impact of diversifications in Boreal regions, Finland, where different proportions of legumes and grass were considered in a 4-year crop rotation compared with conventional cereal rotations. Experiments and modeling showed that the loss of SOC in conventional cereal was compensated when grass was introduced in the rotations. A good agreement (NRMSE <10%) and a nonsignificant bias were observed between model and experimental data for all sites. Mitigation scenarios considered in the modeling analysis for the test site Huesca showed that an integrated management of no tillage and manure is the best strategy to increase SOC, ∼51% over 20 years, compared with the baseline scenario (current farmers practic

The implementation of alley cropping in orchards can be a sustainable strategy to increase farm productivity by crop diversification and contribute to climate change mitigation. In this research, we evaluated the short-term effect of alley cropping with reduced tillage on soil CO and NO emissions and soil total organic carbon (TOC) in an almond orchard under Mediterranean rainfed conditions. We compared an almond monoculture with tillage in all plot surface (MC) with almond crop with reduced tillage and growth of Capparis spinosa (D1) and almond crop with reduced tillage and growth of Thymus hyemalis (D2). For two years, soil CO and NO were measured, with soil sampling at the start and end of the experimental period. Results showed that CO emission rates followed the soil temperature pattern, while NO emissions were not correlated with temperature nor moisture. Soil CO emissions were significantly higher in MC (87 mg m h), with no significant differences between D1 and D2 (69 mg m h). Some peaks in CO effluxes were observed after tillage operations during warm days. Soil NO emission rates were not significantly different among treatments. Cumulative CO and CO equivalent (COe) emissions were significantly highest in MC. When COe emissions were expressed on a crop production basis, D2 showed the significantly lowest values (5080 g kg) compared to D1 (50,419 g kg) and MC (87,836 g kg), owing to the high thyme yield, additional to the almond yield. No production was obtained for C. spinosa, since at least two more years are required. TOC did not change with time in MC neither D1, but it significantly increased in D2 from 3.85 g kg in 2019 to 4.62 g kg in 2021. Thus, alley cropping can contribute to increase the agroecosystem productivity and reduce CO emissions. However, it is necessary to grow evergreen alley crops such as thyme to obtain short-term increases in soil organic matter. Thus, to estimate increases in TOC with alley cropping, the plantation density and the