The intensive use of mineral (M) fertilizers may cause harm the environment via leaching or greenhouse gas emissions, destroy soil fertility as a consequence of loss of soil organic matter, and, due to their high price, they are economically unviable for producers. It is widely accepted that organic (O) fertilizers may deal with pressing challenges facing modern agriculture, even if farmers need to improve their knowledge for applying in fertilization programs. A meta-analysis approach has been adopted to evaluate the effects on soil organic carbon (SOC) and crop yield of O fertilizers, applied alone or in combination with mineral fertilizers (MO) under conventional (CT), reduced (RT), and no-tillage (NT) regimes. The analysis was performed in different climatic conditions, soil properties, crop species, and irrigation management. Organic fertilizers have a positive influence in increasing SOC compared with M (on average 12.9%), even if high values were observed under NT (20.6%). The results highlighted the need for flexible and environment-specific systems when considering organic fertilization subjected to different tillage regimes. Similarly, MO application showed a better crop yield response in CT and RT under coarse soils when compared with M fertilizer applied alone (on average 13.4 and 12.7%, respectively), while in medium-textured soils, CT and RT yielded better than NT under O fertilizers (9.5 and 11.2 vs. 2.5%, respectively). Among the crop species, legumes performed better when O fertilizers were adopted than M fertilizers (on average 15.2%), while among the other crop species, few differences were detected among the fertilization programs. Under irrigated systems, RT and NT led to higher productivity than CT, especially under MO treatments (on average 9.2 vs. 3.4%, respectively). The results highlighted the importance of the environmental and agronomical factors and how their understanding could affect the impact of these conservation farming practices on crop productivity to improve the sustainability of the farming system in a specific region.

Salinity is a significant environmental stress factor limiting crops productivity. Barley (Hordeum vulgare L.) has a natural tolerance to salinity stress, making it an interesting study object in stress biology research. In the present study, for the first time the effect of salinity stress on barley inflorescence developmental stages was investigated. Five spring barley genotypes irrigated with saline water (12.5 ds/m NaCl) were compared to controls treated with normal tap water. We measured abscisic acid (ABA) concentrations in the apical, central and basal sections of the immature inflorescence at green anther (GA) stage. The role of ABA in spikelet primordia development, atrophy and abortion and final yield was evaluated. A time course experiment starting from double ridge until green anther (GA) stages revealed that salinity reduced the length of spike developmental stages in all genotypes causing shortened of the plant life cycle. The shortened plant life cycle negatively affected plant height and number of tillers/plant. Salinity also affected spikelet primordia development. In both control and salinity treated plants apical spikelet abortion started in late awn primordium (AP) stage. However, under salinity treatment, significantly more spikelets were aborted, thus directly affecting plant yield potential. ABA, which plays a role in the spikelet/floret abortion process, was markedly elevated in the base and apex of salt treated spikes correlating with an increased spikelet abortion in these regions. Overall, salinity treatment reduced all plant and yield-related parameters investigated and turned some of the correlations among them from positive to negative or vice versa. Investigations of ABA role in floral development and phase duration of barley spike showed that, ABA regulates the spikelet/floret abortion process affecting the yield potential under salinity and control conditions.

Crop yield under reduced tillage (RT) practices is a concern for sustainable production worldwide because it is related to different environmental and agronomic factors than conventionally tilled soils. This study aimed to evaluate how climate, soil, and farming practices could affect crop yield under RT, especially under different sources of fertilisation [mineral (M), mineral + organic (MO), and organic (O)]. Multilevel meta-analysis was adopted. The analysis was performed taking into consideration environmental conditions, soil properties, crop rotation, and crop species. Only studies that reported the interaction effect of soil tillage and nutrients management on grain yield were included. The results suggest that the impact of soil tillage and fertilisation sources on crop yield depended on crop species. Using reduced tillage practices, adopting only organic nutrient sources could produce enough grains for legume crops. However, combining both inorganic and organic fertilizers added benefits for cereal crops in terms of grain yield production. This study highlights how conservation tillage practices could be affected by environmental and agronomic factors.

Intensive agronomic practices such as deep and repeated tillage and applying high mineral fertilization rates to improve crop yields have gradually determined soil resource degradation. A study was carried out over a two-year period (2015 and 2016) to assess effects of tillage (plough; subsoil; and spading) and fertilization (mineral vs. organic) on soil health relative to carbon and nitrogen dynamics in potato crop in the Mediterranean environment. Microbial indices could be successfully used as tool for assessing soil health in terms of predictors and indicators of carbon sequestration and nitrogen availability. The microbial quotients, calculated as percentage of the microbial-C to total organic C (C_mic:C_org), was significantly higher in subsoiling than in plowing and spading soil tillage, and higher in 2016 (3.19%) than 2015 (1.72%). The activity of enzymes involved in C cycle was significantly higher in subsoiling and spading than in plowing, while acid phosphatase was positively affected by spading and arylsulfatase increased with plowing. The whole enzyme activity expressed as synthetic enzymatic index (SEI) was positively affected by subsoiling and plowing in 2015 (4254) compared to spading tillage (3934). A general decrease in soil enzyme activity in 2016 than 2015 was observed. The subsoiling in potato crop favored the immobilization of carbon and nitrogen during the wet spring–summer period. Conversely, the plowing favored the mineralization process when the spring–summer period became more dried.

Farming practices such as cover cropping, crop rotation systems, and soil tillage practices, along with climate conditions and soil type play important roles in determining final crop production. Numerous empirical studies have documented the heterogeneous effects of cover crops on the yield of successive crops, exhibiting variations across diverse regions, climate regimes, soil characteristics, cover crop types, and agricultural management practices. A meta-analysis was conducted to comprehensively summarize and evaluate the impact of cover crops (CCs) in the agroecosystem. The main goal of the study is to promote a transition towards more sustainable cereal crop production by exploring the potential of currently unexploited CCs in Europe. The study demonstrated that the incorporation of legume CCs resulted in the most pronounced and statistically significant increase in grain yield among cereal crops. CCs from the Brassicaceae family also demonstrated a positive impact on grain yield under southern European climates. Cover cropping had a positive effect on the subsequent cash crop under conventional tillage practice. A positive, but not significant impact, was detected under both conservation tillage practices, which include reduced tillage (RT) and no-till (NT). The result of the study suggests that NT practices are more suitable for Northern Europe, while RT practices are preferable for Southern Europe zones. This study indicates that the adoption of cover cropping represents a viable and effective agronomic strategy for enhancing grain yield in cereal crops cultivated across European agricultural systems.