Proximal soil sensors are receiving strong attention from several disciplinary fields, and this has led to a rise in their availability in the market in the last two decades. The aim of this work was to validate agronomically a zone management delineation procedure from electromagnetic induction (EMI) maps applied to two different rainfed durum wheat fields. The k-means algorithm was applied based on the gap statistic index for the identification of the optimal number of management zones and their positions. Traditional statistical analysis was performed to detect significant differences in soil characteristics and crop response of each management zones. The procedure showed the presence of two management zones at both two sites under analysis, and it was agronomically validated by the significant difference in soil texture (+24.17%), bulk density (+6.46%), organic matter (+39.29%), organic carbon (+39.4%), total carbonates (+25.34%), total nitrogen (+30.14%), protein (+1.50%) and yield data (+1.07 t ha⁻¹). Moreover, six unmanned aerial vehicle (UAV) flight missions were performed to investigate the relationship between five vegetation indexes and the EMI maps. The results suggest performing the multispectral images acquisition during the flowering phenological stages to attribute the crop spatial variability to different soil proprieties.

Combining remote and proximal sensing in agriculture is essential to monitor crop spatial-temporal variability and to provide high-quality prescription maps for the precision agriculture applications. The study showed how different combinations of soil management (no tillage—NT vs. conventional tillage—CT) and nitrogen (N) fertilization levels (0.90 and 180 kg N ha⁻¹) can affect the durum wheat nutritional status and development through vegetation indices computation and proximal sensing tool application. Chlorophyll and N crop content were measured, in addition a proximal sensing tool and multispectral imagery equipped on unmanned aerial vehicle were used. The N input is the key driver for durum wheat development (4.5 ± 0.92 t ha⁻¹ on average), but when it was not provided the NT performed better than CT (2.51 ± 0.22 vs. 1.46 ± 0.28 t ha⁻¹ respectively) in terms of grain yield. This is due to the greater content of organic matter and N availability which characterizes the NT system. The near infrared (NIR) band-based vegetation indices can well detect the durum wheat nutritional status (R² = 0.70 on average). The showed results can provide an important contribution in the implementation of ago-environmental policies aimed at environmental impact of cereal-based-cropping systems reduction.

Mostly, precision agriculture applications include the acquisition and elaboration of images, and it is fundamental to understand how farmers’ practices, such as soil management, affect those images and relate to the vegetation index. We investigated how long-term conservation agriculture practices, in comparison with conventional practices, can affect the yield components and the accuracy of five vegetation indexes. The experimental site is a part of a long-term experiment established in 1994 and is still ongoing that consists of a rainfed 2-year rotation with durum wheat and maize, where two unfertilized soil managements were repeated in the same plots every year. This study shows the superiority of no tillage over conventional tillage for both nutritional and productive aspects on durum wheat. The soil management affects the vegetation indexes’ accuracy, which is related to the nitrogen nutrition status. No-tillage management, which is characterized by a higher content of soil organic matter and nitrogen availability into the soil, allows obtaining a higher accuracy than the conventional tillage. So, the users of multispectral cameras for precision agriculture applications must take into account the soil management, organic matter, and nitrogen content.

In Mediterranean cropping systems, it is important to utilise marginal lands for the cultivation of native food crops. Previous research on Crithmum maritimum L., a species native to southern Europe, has focused on its alimentary and chemical parameters. The aim of the present study was to identify the effects of irrigation and fertigation systems on C. maritimum in Mediterranean cropping systems. We planted C. maritimum seeds in an organic farm in Italy, and we carried out three experiments (fertigation, irrigation, and control) with three replications each. We evaluated plant phenological development and biomass production. We found that these treatments significantly influenced plant phenology and biomass parameters. Even with low irrigation and fertigation, this species showed a significant difference in the Bundesanstalt, Bundessortenamt, CHemischeIndustrie (BBCH) phase at harvest: in fact, there were 39 and 35 leaves on the main stem in the irrigation and fertigation treatments, respectively, while there were 29 leaves on the main stem in the rainfed unfertilised control. Biomass production also showed the same significant difference: 1.8 and 2.0 t ha⁻¹ of total dry biomass in the irrigation and fertigation treatments, respectively, and 1.2 t ha⁻¹ of total dry biomass in the rainfed unfertilised control. In conclusion, we recommend the use of C. maritimum for food production in Mediterranean organic cropping systems.

Mostly precision agriculture applications pass by an acquisition and elaboration of images, which allow us to detect the spatial-temporal variability of the crop, so it is fundamental understand how those images and relate vegetation indexes can be affected by farmers practices. We investigated how long-term conservation agriculture practices, in comparison with conventional practices, and nitrogen fertilization levels can affect the productivity of durum wheat and the accuracy of five vegetation index categories to well describe the biomass and nitrogen crop status. The experimental site is a part of a long-term experiment established in 1994 and is still on-going consisting on a rainfed 2 years rotation with durum wheat and maize, where two tillage management (no tillage vs conventional tillage) and three nitrogen fertilizer treatments (0, 90 and 180 kg N ha ^-1 ) were repeated in the same plots every year. At three different phenological stages we acquired multispectral imagery aimed to test the accuracy of vegetation indices to well represent the total biomass weight (gm ^-2 ) and biomass nitrogen content (g N m ^-2 ) in relation to the soil managements and nitrogen fertilization rates. In addition, at crop maturity, we measured the yield components for all compared treatments. The most important key driver in achieving maximum productivity is nitrogen fertilization. The accuracy of the vegetation indices depends on the soil managements, nitrogen fertilizations and background soil noise. The evaluation of which vegetation index use to represent the durum wheat status defines the quality of vegetation and prescription maps for precision agriculture applications.

In Mediterranean cropping systems, it is important to utilize marginal lands for the cultivation of non-food crops. Spontaneous thistle genera such as Cynara cardunculus L. and Onopordum tauricum Willd. are native to southern Europe. Previous research has focused on their spontaneous growth in the environment or ability to supply biofuel. The aim of this study was to identify the effect of two different planting densities on the flower differentiation, vegetable rennet production and weed control of O. tauricum Willd. and C. cardunculus L. in rainfed unfertilized Mediterranean cropping systems. The results showed that plant density influenced most of the biomass parameters for O. tauricum Willd. but no significant differences were observed for C. cardunculus L. Higher densities of both species were beneficial for weed control. We recommend the use of C. cardunculus L. and O. tauricum Willd. as suitable species for vegetable rennet production in Mediterranean organic cropping systems.