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A biennial experiment (2009 and 2010) was conducted at Calvi (Benevento, Southern Italy) to evaluate the effect of compost by organic fraction municipal solid waste (OFMSW), in combination with mineral nitrogen (N) fertilization, on yield and quality of three Dark Fire-cured (Kentucky) tobacco cultivars commonly cultivated at Benevento province (Campania region, Southern Italy). Six N fertilization treatments (N0 = soil N reserves available for plant growth; MIN = 135 kg ha−1 of N applied as mineral fertilizer; C10 = 10 Mg d.w. ha−1 compost; C10N = 10 Mg d.w. ha−1 compost + 50% MIN; C20 = 20 Mg d.w. ha−1 compost; C20N = 20 Mg d.w. ha−1 compost + 50% MIN) were combined with the following cultivars: (i) Foiano, medium early maturing; (ii) Riccio Beneventano (local ecotype), medium maturing; (iii) SKL, medium maturing. Yield of cured leaves (Mg ha−1) and growth components (number of leaves per plant, mean individual leaf area, leaf area per plant, specific leaf weight, stem diameter and height) and color parameters (L*, a*/b*) were measured. Leaf quality traits (nitrates, total N and alkaloids contents, score) and N use efficiency were also determined. The best growth and yield performance was reached in 2010 when plants were taller, developed both stems that were more robust and leaves having greater individual leaf area, and showed a higher leaf area per plant than in the first year. Regardless of the form of applied N (compost, mineral fertilizer, or a combination of both), tobacco plants appeared to be directly and positively influenced by increasing quota of readily available N received by each treatment, which was determined at the beginning of field growth by N soil balance and taking into account the percentage of N supplied by organic (compost) and mineral fertilizers. Results obtained with compost treatments, particularly when combined with mineral fertilizer (at C10N more than C20N), appeared comparable or sometimes better than those of full mineral fertilization although N fertilization by synthetic products was applied at very low doses.

The quantity and quality of wall rocket (Diplotaxis tenuifolia L.) production are strongly influenced by the cultivation system, in particular the protected environment conditions and nitrogen fertilization. In the present research, we tested two greenhouse cover films (Film1: diffuse light; Film2: clear), to verify the effects on yield and nitrate content (a detrimental factor of quality) of rocket leaves, fertilized with optimal (N2) or sub-optimal nitrogen dose (N1), or unfertilized (N0). In addition, we combined the N fertilization with a biostimulant application, declared by the manufacturer as able to reduce nitrate content. Film1 provided a 36% yield increase over Film2 and allowed an increasing production until the V harvest, opposite to what was recorded under Film2, where the yield increased only until the III harvest. Additionally, biostimulant application boosted the yield (+40%), as well as nitrogen fertilization. Both factors had the best performance under Film1, where N1 yield was even equal to N2-Film2. The nitrate content showed a seasonal trend (lower values in spring harvests) and it was boosted by nitrogen (1096, 3696, and 4963 mg/kg fresh weight, for N0, N1, and N2, respectively) and biostimulant application (3924 vs. 2580 mg/kg fresh weight). Therefore, the use of diffuse-light film seems useful to obtain higher yield with a halved N dose as well as in combination with biostimulant application, but the latter did not confirm the capacity to contain nitrate, at least for this crop and in this cultivation system.

The use of biostimulants in modern agriculture has rapidly expanded in recent years, owing to their beneficial effects on crop yield and product quality, which have come under the scope of intensive research. Accordingly, in the present study we appraised the efficacy of two plant-derived biostimulants, the legume-derived protein hydrolysates Trainer® (PH), and the tropical plant extract Auxym® (TPE) on two lettuce cultivars (green and red salanova®) in terms of morpho-physiological and biochemical traits (primary and secondary metabolites). The two cultivars differed in their acquisition capacity for nitrate and other beneficial ions, their photosynthetic and transpiration rates, and their ability to synthetize and accumulate organic acids and protective metabolites. The biostimulant effect was significant for almost all the parameters examined but it was subjected to significant cultivar × biostimulant interactions, denoting a cultivar-dependent response to biostimulant type. Notwithstanding this interaction, biostimulant application could potentially improve the yield and quality of lettuce by stimulating plant physiological processes, as indicated by the SPAD index (leaf chlorophyll index), ACO2 (assimilation rate), E (transpiration), and WUEi (intrinsic water use efficiency), and by increasing concurrently the plant mineral content (total N, K, Ca, Mg) and the biosynthesis of organic acids (malate, citrate), phenols (caffeic acid, coumaroyl quinic acid isomer 1, dicaffeoylquinic acid isomer 1), and flavonoids (quercetin-3-O-glucuronide, quercetin-3-O-glucoside). Biostimulant action may facilitate the bio-enhancement of certain lettuce cultivars that are otherwise limited by their genetic potential, for the accumulation of specific compounds beneficial to human health.

Supplementary lighting of specific wavelengths can be used for inducing morphological and physiological responses in different crops, ultimately improving yield and quality. Based on this approach, new greenhouse covering materials are being developed in order to improve the use of sunlight in horticulture. These new-generation greenhouse coverings may incorporate light spectrum modulation agents or fluorescent additives which convert solar UV radiation into visible light. In this work, we tested the agronomical and physiological response of lettuce grown under a greenhouse covered with poly-methyl-methacrylate (PPMA) panels doped with a blend of the rare-earth inorganic material with a photo-luminescent effect. The doped greenhouse elicited a 36% increase in lettuce yield compared to the undoped greenhouse. Chlorophyll and carotenoid content, as well as antioxidant activity and ascorbic acid content, were not affected by greenhouse cover, but the doped panels induced a 22% reduction in total phenolics and a 14% increase in nitrate content in leaves. The greenhouse covering materials also affected the photochemistry of photosynthesis, as the daily fluctuations in both the effective quantum yield (ΦPSII) and the electron transport rate (ETR) were attenuated under the doped greenhouse. Non-photochemical quenching (NPQ) was closely related to the light environment in all experimental conditions, with the highest values at 14:00 h. Our results showed that the red-supplemented light spectrum under the doped greenhouse cover contributed to increased plant growth and yield, with a corresponding effect on the physiology of photosynthesis.

Lettuce (Lactuca sativa L.) is one of the most popular leafy vegetables, appreciated globally as a low-calorie food with bioactive compounds. The application of a low dose of abiotic stress is considered a sustainable pre-harvest strategy to modify the nutraceutical value of horticultural products. In this work, we explored the response of two differently colored (red or green) baby leaf lettuce varieties to four NaCl concentrations in the nutrient solution (from 1 to 30 mM), using a full factorial design. We focused on leaf morphological parameters and possible phytochemical enhancement of the main polyphenols and anthocyanins, analyzed by LC-MS. The response to low-to-moderate salt stress exposure was affected mainly by salt concentration for leaf traits or by the cultivar for leaf color, with very limited factors’ interactions. Multivariate analysis indicated a predominant role of the genotypic factor in shaping differences in the two weeks growing cycle for baby leaf lettuce. Phytochemically, different dose–response models to sub-optimal saline conditions may be applied to the various compounds. A significant hormetic stimulation was present only for cyanidin-malonyl glucoside, the main anthocyanin present in the red cultivar.

The soil mulching is an important agricultural practice for increasing crop productivity and earliness. Mulching can be made with natural or synthetic materials. The common films being used these days are usually made of low density polyethylene (LDPE), but its disposal can represent a serious environmental and economic problem. The biodegradable mulching can overcome these problems. Two experiments were carried out comparing the effects of biodegradable and LDPE mulching films on yield and quality of zucchini (Cucurbita pepo L.) grown in two environments (open-field vs. greenhouse). In both the environments a randomized complete block design was adopted. The treatments composed of no-mulched crop (control), soil covered by 15 microns black biodegradable film (MB15) and soil covered by 50 microns black LDPE film. The results showed that MB15 was able to maintain discrete technical proprieties until the end of cycle, especially in greenhouse, assuring a sufficient heating of soil, similar to LDPE. The soil heating promoted crop development. Furthermore, earliness was increased (84 in greenhouse vs. 99 days in open air) in greenhouse. The early production of zucchini grown on MB15 was similar to the one in LDPE production in greenhouse. The total marketable yield of plants grown on both films was not different but it was lower in open air. The biodegradable film significantly improved fruits quality, with higher values of firmness and total soluble solid than fruits grown on LDPE.

In the 21st century, global climate change is a key concern for countries all over the world as, in the future, crops will face several extreme events, including an increase of 2–4 °C in the mean temperature with a possible consequent reduction in yield. Wheat (Triticum durum Desf) is one of the most important foods as it provides 20% of the protein for the world population. Since temperature is one of the most limiting factors of crop development, the aim of this trial was to verify the agronomic response of durum wheat to a temperature increase of about 1.5–2.0 °C through the use of short-time adjustment techniques, such as sowing time and variety choice. The experiment foresaw the comparison between two different temperature conditions (ordinary, OT—in the open field, and high, HT—under a polyethylene tunnel), two sowing times (ordinary—OS, and delayed—DS), and three varieties (Ofanto, modern variety; Cappelli, traditional variety; and a mix of the two). HT conditions caused a decline in the wheat yield (−52.5%), but without differences between the two sowing times. The grain quality resulted positively when affected by late sowing times with an increase in 1000 seeds weight and protein percentages and a decrease in shrunken grains. Therefore, it seems that in areas characterized by high temperatures, delayed sowing can improve grain quality without reducing yield quantity compared to ordinary sowing times.

Promising strategies that could aid a shift from N-intensive agriculture to an eco-friendlier approach include the integrated use of plant-based biostimulants. To date, results about the accumulation of nitrate in green leafy vegetables due to biostimulant application are conflicting. Therefore, the current study aimed at assessing the effect of a new plant-based biostimulant, containing triacontanol (TRIA), that is claimed to reduce nitrate accumulation in leaves, based on the yield and leaf quality of lettuce grown in a plastic tunnel under different N conditions. The experimental design was a factorial combination of three nitrogen fertilization levels (N0, N30, and N60, corresponding to 0, 30, and 60 kg N ha−1) and two biostimulant applications (treated with ‘ILSASTIM+’ = YB and untreated control = NB). Nitrogen fertilization resulted in a 40% yield increase over N0. Biostimulant application increased the yield 21% over NB, and both improved all growth parameters. In addition, the biostimulant had a positive effect on color and Soil Plant Analysis development (SPAD) index, thus enhancing the qualitative aspect. Interestingly, biostimulant application boosted nitrogen use efficiency with a 23% increase over untreated plants. The use of biostimulant proved to be suitable to be applied in a sustainable strategy of production and quality improvement.

Tomato (Solanum lycopersicum L.) is a diffused worldwide vegetable. Great amounts of fertilizers are often applied for increasing yield and quality, without considering the negative effect on the environment. A possible perspective for reducing this risk is to raise the nitrogen use efficiency (NUE) through the use of plant biostimulants, which also improve yield and quality concomitantly. The aim of the current study was to verify the potential beneficial effect of three vegetal-based biostimulants on agronomical, qualitative and nitrogen use efficiency of a processing tomato crop. The experiment provided three biostimulants (an extract of brown seaweed [SwE], a legume-derived protein hydrolysate [LDPH] and a tropical plant extract). The following assessments were carried out: marketable and unmarketable yields, mean fruits weight, firmness, pH, total soluble solids (TSS), colour parameters (a/b), hydrophilic antioxidant activity (HAA), lipophilic antioxidant activity (LAA), total ascorbic acid content (AsA), total phenols, nitrate and total nitrogen content, nitrogen use efficiency, N-uptake efficiency, and N-utilization. The foliar application of biostimulants especially protein hydrolysates and seaweed extract significantly affected the marketable yield with an average increase of 18.3% over the control and 41.3% average decrease in unmarketable yield. The N-use and N-uptake efficiency followed a similar trend, with biostimulants boosting it higher than control, +18.4% and +59.3%, respectively; the nitrogen content was also higher in fruits of sprayed plants: +21.3% over control. This finding also reflects on higher dry matter accumulation and firmness in fruits of treated plants (+10.9% and +14.1% over control, respectively). The biostimulants application, in particular SwE and LDPH, also boosted TSS (+12.8%), the a/b colour ratio (+7.5%), HAA and AsA (9.8% and 114.6%, respectively). Therefore, the legume-derived protein hydrolysates and extract of brown seaweed Ecklonia maxima seem a good sustainable approach to improve yield and quality of tomato for canning industries. Highlights - The effects of three plant-based biostimulants on yield and quality of processing tomato was explored. - Application of protein hydrolysates and seaweed extract improve marketable yield. - The biostimulants had different effect on nutritional and functional quality of tomato. - Hydrophilic antioxidant activity and ascorbic acid content increased under protein hydrolysate application.

Municipal waste compost was evaluated under open field conditions for replacing synthetic fertilizers in a vegetable three-year succession. Three compost rates, 45 t ha–1, 30 t ha–1 and 15 t ha–1 (dry matter), and compost at 15 t ha–1 combined with 25%, and 50% of the full synthetic nitrogen rate, were compared to full and none synthetic nitrogen fertilizations. Crop succession was: tomato followed by endive in the first year; eggplant and, then, broccoli in the second year; tomato and, then, endive/broccoli, in the third year. The application of compost at a dose of at least 30 t ha–1 or at 15 t ha–1 with the addition of 25% of the full synthetic nitrogen rate, in Spring-Summer cycle, sustained growth and yield at levels comparable with those of synthetic nitrogen fertilization. However, only a very poor residual effect of the compost soil treatment on the yield of Autumn-Winter crops, was observed. Monitoring of nitrate content into the soil during cropping seasons, a reduction of the risk of groundwater pollution was displayed due to nitrates released by compost, respect to synthetic nitrogen fertilizer. The cumulative effects of compost application on soil properties were detected at the end of the field trials, registering changes in chemical parameters analysed, except for phosphorus and boron. Highlights - Municipal solid organic waste compost (MSWC) integrated with N fertilizers can sustain vegetable production. - MSWC (at least 30 t ha–1 d.w.) replaced synthetic fertilizers for tomato and eggplant productions. - N fertilizer integration to the compost residual effect is necessary to sustain endive and broccoli productions. - MSWC (at 15 t ha–1 d.w.) needs 25% of N integration to reduce the gap with plant only fertilized with N fertilizer. - MSWC preserved soil quality and avoided accumulation of undesired metals, such as Cu and Zn.

Climate change is one of the most important and studied phenomena of our age and it can have a deep impact on agriculture. Mediterranean countries are and will continue to be strongly affected by changing environmental factors, including lack of precipitation and prolonged heatwaves. The current study aimed to assess the adaptability of an early maize hybrid grown in two temperature conditions and subjected to different irrigation water regimes. The experimental design was a randomized complete-block design with two different temperature conditions: (i) ordinary temperature in open field (OF) and (ii) high temperature (about 3 °C higher than the current condition) under a poly-ethylene tunnel (PE). In both environments, five irrigation level treatments were applied: 100% (DI100), 75% (DI75), 50% (DI50), 25% (DI25), and 0% restoration of water lost by evapotranspiration (DI0). The responses of maize plants were assessed in terms of yield, nitrogen content determination, nitrogen use efficiency, leaf gas exchanges, and leaf water potential measurements. In both conditions, yield and its components linearly decreased as the irrigation water amount reduced, and even the DI0 plants did not produce. Notably, the PE-DI100 treatment had a significantly higher yield than the corresponding treatment in the open air (9.9 vs. 8.5 t ha−1), due mainly to the increased number of ears per square meter (13 vs. 11 m2, respectively). Though, as far as it concerns physiological parameters, a significant effect of environmental conditions was found, with values significantly lower under the protected environment, compared to the plants in the open field. Considering our results, it can be assumed that correct management of amount and time intervals of irrigation could adapt the maize to future climate change.

A mild salinity stress (eustress) may modulate the induction of the plant defense system in horticultural crops and the synthesis of phytochemical components able to enhance plant resilience, post-harvest performance, and the nutraceutical quality of produce. However, the choice of the correct eustress type and dose to induce the synthesis of these protective phytochemicals is pivotal to avoid potential interference with plant growth and productivity. In order to study how green and red lettuce (Lactuca sativa L.) plants equilibrate the nutritional and nutraceutical components of quality with yield components, we applied iso-osmotic concentrations of three different salts (20 mM NaCl, 20 mM KCl, and 13.3 mM CaCl2, with a final total ionic concentration of 40 mM) in combination with two successive harvests in a floating raft system. The biometric parameters, mineral composition, bioactive compounds, and antioxidant activity of both cultivars were analyzed. The green cultivar had a superior response concerning biometric traits and productivity compared to the red one during the first cut but lower phytochemical content (e.g., ascorbic acid). The effect of cut order, independently of cultivar and salinity treatments, demonstrated that at the first harvest plants could redirect metabolism by increasing the lipophilic antioxidant content (LAA) at the expense of plant yield, therefore increasing plant resilience and post-harvest nutraceutical quality, whereas, at the second harvest, plants reverted principally to tissue expansion. The treatments with iso-osmotic salt concentrations did not affect K and Mg ion contents but further increased LAA and resulted only in a moderate decrease of fresh yield. The lettuce nitrate content was reduced during the second cut only when lettuce plants were treated with NaCl and especially CaCl2.

Tobacco is an annual cash crop widely cultivated over the world, which generally needs great amounts (N) of nitrogen to achieve the best yield and quality. However, with a view to sustainable and environmentally friendly agriculture, also for this crop, the reduction in N fertilization is a priority, but without negatively affecting the yield and quality of the cured product. Therefore, field experiments were conducted during 2002 and 2003 on light air-cured (Burley) tobacco at three different locations of the Campania region (Southern Italy) where high-quality light air-cured (Burley) tobacco is traditionally cultivated. At each location, the following six N fertilization treatments were compared with four replications (blocks): (i) a not fertilized control (N0), (ii) 50 kg N ha−1 (N50), 90 kg N ha−1 (N90), 130 kg N ha−1 (N130), 170 kg N ha−1 (N170), 210 kg N ha−1 (N210). The yield of cured leaves appeared positively influenced by N fertilization but not at a rate higher than 170 kg ha−1. N fertilization directly influenced nitrates and the total N content of cured leaves at all locations. The greater values of both parameters were reached at N130 or N90, respectively, at Vitulazio (CE), N170 at Bellizzi (SA), and N90 at San Giorgio del Sannio (BN). The fire holding capacity increased with N fertilization up to N170 treatment (12–13 s at CE and BN but just 8 s at SA). L* (brightness) decreased with increasing N fertilization giving cured leaves less bright and opaquer. The a/b ratio (a*, green/red, b*, blue/yellow) increased with N treatments producing cured leaves of dark hazelnut. The best scores were assigned to cured products obtained by plants fertilized with 170 kg N ha−1. N-use efficiencies were negatively influenced by N fertilization. The best NUE and N-uptake efficiency was recorded in 2002 at Vitulazio (CE), in spite of a higher NO3-N before N fertilization than other locations.

Barley is the primary matrix for malting process of beer production. Farmers count on increasing cultivation inputs, especially nitrogen fertilization, in order to reach a higher yield. Nevertheless, an overuse of nitrogen, besides causing environmental damages, can determine a deterioration of quality traits of malting barley, in particular an increase in grains protein content, which should range between 10 and 11% as required by the mating industry. Over two successive years, barley was grown under 4 different nitrogen (N) doses—0 kg N ha−1—N0; 20 kg N ha−1—N20; 40 kg N ha−1—N40 and 60 kg N ha−1—N60, and subject to a biostimulant treatment (Ecklonia maxima seaweed extract). Barley yield and growth parameters increased with nitrogen and seaweed application. N40 was already sufficient in the second year to reach the plateau of the highest production. Biostimulant application increased 17.9% the nitrogen use efficiency, 15.7% the biomass production, and 17.0% the yield with respect to untreated plants. Our results indicate that a significant reduction in nitrogen is possible and desirable, combined with the application of a plant-based biostimulant like seaweed extract, which determines an improvement in nitrogen use efficiency, assuring a higher production and lower fertilization inputs.

Scientists, extensions specialists, and growers are seeking sustainable agricultural practices that are able to cope with these objectives in order to ensure global food security and minimize environmental damage. The use of mulching films and plant biostimulants in agriculture seems to be a valid solution for tackling these rising concerns. A greenhouse experiment was conducted in order to elucidate the morpho-physiological and nutritive characteristics of lettuce (Lactuca sativa L.) in response to foliar application of a tropical plant extract (PE) biostimulant and the use of plastic mulches. Two biodegradable mulch treatments (Mater-Bi&reg, 1 and Mater-Bi&reg, 2) were compared to black polyethylene (LDPE) and bare soil. Biodegradable mulch film Mater-Bi&reg, 1 produced a comparable marketable fresh yield to the commercial standard polyethylene (LDPE), whereas Mater-Bi&reg, 2 exhibited the highest crop productivity. When averaged over biostimulant application, lettuce plants grown with biodegradable film Mater-Bi&reg, 2 exhibited superior quality traits in terms of K, Ca, total ascorbic acid, and carotenoids content. The combination of film mulching (LDPE, Mater-Bi&reg, 1 or Mater-Bi&reg, 2) with the tropical plant extract biostimulant exhibited a positive and significant synergistic effect (+30%) on yield. The PE-biostimulant induced higher values of SPAD index and total chlorophyll content when compared to untreated greenhouse lettuce. The mineral content of leaf tissues was greater by 10% and 17% (for P and Ca, respectively) when compared to the untreated lettuce (no PE application). Nitrate content was significantly reduced by 23% in greenhouse lettuce plants receiving PE as compared to the untreated control. The positive effect of Mater-Bi&reg, 2 film on the ascorbic acid content has also been highlighted when combined with the biostimulant application, where a major amplification of total ascorbic acid (+168%) was recorded in comparison to the untreated lettuce. Overall, our work can assist leafy vegetables growers in adopting good agricultural practices, such as biodegradable plastic mulches and vegetal-derived biostimulants, to improve the sustainability of greenhouse production.

The global increasing demand of lettuce is pushing farmers to boost their production through several technical means, including mulching and nitrogen fertilization. However, from an environmental protection perspective, the role of scientific research is to limit the excessive use of some chemical approaches. This research aims to evaluate the possible effects of two mulching films (black polyethylene, PE, and brown photoselective film, BF) and two treatments with a plant growth-promoting product, containing Trichoderma spp., (non-treated, - Control and treated with RYZO PEP UP, - TR), on the productive and qualitative traits of lettuce grown under four regimes of nitrogen (0, 30, 60 and 90 kg ha&minus, 1, N0, N30, N60, and N90, respectively). The marketable yield increased at higher nitrogen levels, but without differences between the N60 and N90 doses. The photoselective film elicited marketable yield, with an 8% increase over PE. N fertilization also improved photochemical efficiency (higher Soil Plant Analysis Development and chlorophyllous pigments biosynthesis), as well as antioxidant activities (lipophilic&mdash, LAA and hydrophilic&mdash, HAA) and bioactive compounds (phenols and total ascorbic acid&mdash, TAA). Interestingly, Trichoderma spp. had a positive effect on these qualitative parameters, especially when combined with mulching films, where the increase generated by PE-TR treatment over the all other treatments was 16.3% and 16.8% for LAA and HHA, respectively. In all treatments, the nitrate leaves content was consistently always within the legal limit imposed by the European community. Overall, although Trichoderma spp. did not engender a marked effect on yield, probably due to the short crop cycle, its positive effect on some quality traits is an interesting starting point for further research.

Crop management and soil properties affect greenhouse gas (GHG) emissions from cropping systems. Irrigation is one of the agronomical management practices that deeply affects soil nitrous oxide (N2O) emissions. Careful management of irrigation, also concerning to soil type, might mitigate the emissions of this powerful GHG from agricultural soils. In the Mediterranean area, despite the relevance of the agricultural sector to the overall economy and sustainable development, the topic of N2O emissions does not have the same importance as N2O fluxes in temperate agricultural areas. Only some research has discussed N2O emissions from Mediterranean cropping systems. Therefore, in this study, N2O emissions from different soil types (sandy-loam and clay soils) were analyzed in relation to the irrigation of a maize crop grown in two contrasting seasons (2009&ndash, 2010). The irrigation was done using a center pivot irrigation system about twice a week. The N2O emissions were monitored throughout the two-years of maize crop growth. The emissions were measured with the accumulation technique using eight static chambers (four chambers per site). Nitrogen fertilizer was applied in the form of ammonium sulphate and urea with 3,4 dimethylpyrazole phosphate (DMPP) nitrification inhibitors. In 2009, the N2O emissions and crop biomass measured in both soil types were lower than those measured in 2010. This situation was a lower amount of water and nitrogen (N) available to the crop. In 2010, the N2O fluxes were higher in the clay site than those in the sandy-loam site after the first fertilization, whereas an opposite trend was found after the second fertilization. The soil temperature, N content, and soil humidity were the main drivers for N2O emission during 2009, whereas during 2010, only the N content and soil humidity affected the nitrous oxide emissions. The research has demonstrated that crop water management deeply affects soil N2O emissions, acting differently for denitrification and nitrification. The soil properties affect N2O emission by influencing the microclimate conditions in the root zone, conditioning the N2O production.

Tomato (Solanum lycopersicum L.) is a globally important vegetable recognized for its positive health benefits. As most of the vegetable production, tomato require significant amount of agronomic inputs. However, recent shifts in climate patterns in terms of timing and amount in rainfall, patterns in air temperature, and the associated extreme events have caused harm and disruption to the agricultural sector worldwide. The objective of this study was to: i) evaluate the ability of a crop simulation model to simulate yield and growth parameter of a processing tomato in South west Italy; ii) quantify the impacts of projected climate on business as usual agronomic practices; iii) understand the role of projected changes and increased CO2 on the water and nutrient efficiency. Field trials from an open field at Sele Valley (40°35′03.8″ N, 14°58′48.6″ E) (Salerno, South west Italy) during a two-year period (2004–2005) were used. Baseline climate data (1984–2018) were available and four contrasting projections were selected as function of their spread in terms of changes in growing season rainfall and temperature respect to the baseline. The crop model DSSAT (Decision Support System of Agrotechnology Transfer) was used for this study. The model was able to simulate tomato response to N fertilization with acceptable error levels respect to the ones reported in literature. The projected increase in air temperature and changes in rainfall caused a shortening ranging from 1.5 to 3 days in tomato phenology causing an overall 15 % reduction in tomato yield. To offset the negative impact of rainfall and temperature changes, additional irrigation water (from 85 to 110 mm) and nitrogen rate (from 20 to 30 kg N ha−1) is needed. However, the increase in irrigation water does not translate in significant yield increase and caused an increase in water and nitrogen use efficiency of less than 10 %.

Soil solarization is usually performed with polyethylene plastic films, which are often disposed of by taking them to landfills, burying them in soil, burning them or occasionally recycling them, and these approaches have a great impact on the environment. Therefore, the use of biodegradable films seems to be an interesting eco-sustainable alternative to traditional films. The effect of soil solarization carried out by using biodegradable mulch or traditional polyethylene plastic film was determined under greenhouse conditions. The response of the soil was assessed by chemical determinations and microbiological culture-dependent and culture-independent approaches to evaluate the microbial biodiversity, biological status and quality of the soil. The biodegradable film avoided a high ammonia concentration in the soil, thanks to both lower soil water content and slightly lower temperature than polyethylene film, and these conditions probably have been optimal for growth of nitrifying bacteria, which were more efficient in BIO, as highlighted not only by lower ammonia value but also by higher nitrate value. Both films did not affect organic matter and total nitrogen content. Moreover, the modifications of the environmental and ecological conditions associated with the different film covers applied to the soils affected prokaryotic and eukaryotic populations, leading to the establishment of a new dominant microbial community. Interestingly, microbiological analyses highlighted a different behavior modulated with the two films indicating different times of recovery post stress. Overall, the results highlighted the potential of biodegradable film that appears to be a suitable replacement for traditional polyethylene plastic film for soil solarization, with great environmental benefits.

Basil (Ocimum basilicum L.) is one of the most common aromatic herbs cultivated all over the world. It is widely used for aromatic and culinary purposes. Two greenhouse experiments were carried out to determine the effects of increasing the level of salinity in the nutrient solution (1 or 40 mM NaCl) during two consecutive growing seasons (summer and autumn) on growth, yield and leaf-quality traits of green sweet basil 'Mammolo' grown in an open-loop system. Increased salinity in the nutrient solution from 1 to 40 mM decreased fresh yield and final leaf area, with a more detrimental effect during the warm season. The percentage reductions in yield and leaf area in comparison with the non-saline control were respectively 30 and 42% in the summer cropping season and 20 and 16% in the autumn season. Increasing the NaCl concentration in the nutrient solution from 1 to 40 mM increased the hydrophilic antioxidant activity (HAA) and total phenolics (TP) by 87 and 17%, respectively, and reduced the nitrate content by 84%. When averaged over salinity level, TP increased and the nitrate content decreased in plants grown in summer compared with the autumn growing season.

An optimized nitrogen (N) fertilization may have a positive effect on leafy vegetables by increasing growth, yield and nutrient content of plants. Nevertheless, crop performance must be coupled with an increase in Nitrogen Use Efficiency (NUE) in order to limit external N inputs and to avoid N surpluses associated with environmental and health problems. The aim of the current study was to assess the effects of a legume-derived plant hydrolysates (LDPH, Trainer&reg, ) and N fertilization levels (0, 2.25 and 4.5 g N m&minus, 2 for spinach and 0, 2.5 and 5.0 g N m&minus, 2 for lamb&rsquo, s lettuce, N0%, N50%, N100%, respectively) on agronomical, biochemical, qualitative responses and NUE of these two important greenhouse leafy vegetables. Spinach and lamb&rsquo, s lettuce were sprayed four times during the growing period (at a concentration of 4 mL L&minus, 1 of LDPH). In baby spinach, the LDPH application elicited a significant increase at the three levels of N fertilization: +16.8%, +14.2%, and 39.4% at 0, 2.25 and 4.5 g N m&minus, 2, respectively. Interestingly, in lamb&rsquo, s lettuce, the N50% plants treated with LDPH reached similar values of marketable yield in comparison to treated and non-treated plants under N100% conditions. The presumed mechanism involved in the enhancement of yield response in the two leafy greens could be associated to a better activity of the photosystem II (higher SPAD index), biochemical (higher content of chlorophyll a, b and total) and leaf nitrate status. The foliar application of LDPH produced a major fortification in lipophilic and hydrophilic antioxidant activities (+11.6 and 6.3% for spinach and lamb&rsquo, s lettuce, respectively). The biostimulant application also improved N-use efficiency and N-uptake efficiency compared to untreated plants: +17.8% and +18.8%, and +50% and +73.3%, for spinach and lamb&rsquo, s lettuce, respectively.

Phytoremediation is a cost-effective “green technology” that uses plants to improve the soil properties of polluted sites, preventing the dispersion of pollutants and reducing the mobility of potentially toxic elements (PTEs) through their adsorption and accumulation by roots or precipitation within the root zone. Being highly tolerant to pollutants and other abiotic stresses, giant reed (Arundo donax L.) is a suitable biomass crop for phytoremediation of contaminated soils. We report the results of a two-year open-air lysimeter study aimed at assessing the adaptability of giant reed to grow on industrial substrates polluted by Pb and Zn and at testing commercial humic acids from leonardite as improvers of plant performance. We evaluated giant reed potential for: 1) biomass production for energy or biomaterial recovery; 2) PTE phytoextraction and 3) soil fertility restoration. Chemical fertility was monitored by measuring soil C while soil biological fertility was estimated by quantifying the abundance of bacterial functional genes regulating nitrogen fixation (nifH) and nitrification (amoA). Giant reed above-ground growth on the polluted soils was slightly lower (− 16%) than on a non-polluted soil, with a preferential storage of biomass in the rhizome acting as a survival strategy in limiting growing conditions. Humic acids improved plant stress tolerance and production levels. As aerial biomass (shoots) did not accumulate PTEs, the plant in question can be used for bioenergy or biopolymer production. In contrast, below-ground biomass (rhizomes) accumulated PTEs, and can thus be harvested and removed from soil to improve phytoremediation protocols and also used as industrial biofuel. Giant reed growth increased the abundance of N-cycling bacteria and soil C in the rhizospheric soil, as well as reduced soil Pb and Zn EDTA extractable fraction.

About half of the irrigated soil is seriously interested from salinity and/or secondary alkalinity. Strogonov in 1964 proposed that the salt tolerance of plants could be improved with different pre-seeding treatments at the seeds. This research has evaluated the germination of maize seeds treated with different methods of priming under saline stress conditions (irrigation water and soil). The experiment has carried in Portici during the summer 2007. The cultivation has been made in a rainout-shelter, in 60 soil plastic pots with a top area of 0.39 m2. Three pre-seeding treatments on maize seeds were compared: 1) soaking with saline solutions (halo-priming); 2) soaking with distilled water (hydro-priming); 3) thermic treatment (thermo-priming). 76 seeds per pot were sowed. Three levels of soil salinity were used for halo-priming: low (LSS): 0.34 mS cm-1; middle (MSS): 0.72 mS cm-1; high (HSS): 3.69 mS cm-1. The ECw of irrigation water was 3.5 dS m-1. During the trial 11 waterings were made twice a week, with an average volume of 1.77 l pot-1. In total for every pot 19.5 l of water and 30 g of salt were given. Every three days it was made the count of germinated seeds. The seed treatments didn’t reduced the germination injury due to the irrigations with saline waters. Particularly for the halopriming the germination was further reduced by the initial soil salinity; in any case, the treatment with the middle salinity determined the greatest percentage of germinated seeds. The treatments with the highest temperatures improved the germination percentage; a similar effect was shown by the smaller duration of thermic treatment. The duration of soaking in distilled water determined positive effects on germination with increases higher than 2% per hour of soaking.