Sustainable Cultivation System Research Articles

The Effects of Soybean–Tea Intercropping on the Photosynthesis Activity of Tea Seedlings Based on Canopy Spectral, Transcriptome and Metabolome Analyses

Intercropping soybean in tea plantations is a sustainable cultivation system that can improve the growing environment of tea plants compared to monoculture tea. However, the effects of this system on the photosynthesis activity of tea seedlings have yet to be reported. Therefore, we used tea cultivar ‘Zhongcha108’ as experimental materials to investigate the effects of intercropping soybean on the canopy spectral parameters and photosynthesis activity of tea seedlings. Canopy spectral reflectance data showed that soybean–tea intercropping (STS) improved the reflectance of 720, 750 and 840 nm bands in tea seedlings’ canopy. The vegetation indexes (VIs) value related to photosynthetic pigments in STS was obviously higher than monoculture tea (T). In addition, the Fv/Fm and SPAD value in STS were also clearly higher. Transcriptome analysis data indicated that STS induced the expression of light-harvesting complex (LHC) genes, photosystem subunit (Psbs and Psas) genes and dark reaction biological process genes (FBP1, RPE, Calvin cycle protein CP12-1 and transketolase). These results indicate that STS enhanced the photosynthesis activity. The metabolome analysis showed that STS promoted the accumulation of carbohydrate metabolites, which further provided evidence for the enhancement of photosynthesis in the leaves of tea seedlings. This study enhanced our understanding of how intercropping soybeans in a young tea plantation improves the photosynthesis activity to promote tea seedlings’ growth and development.

DENSIDADE DE SEMENTES E APLICAÇÃO FOLIAR DE FERTILIZANTE ORGANOMINERAL À BASE DE CÁLCIO E POTÁSSIO NA CULTURA DA AVEIA

Purpose: To present the benefits of increasing oat sowing density on productivity, uniformity, soil quality and reduction of pesticides and the use of an organomineral product based on calcium and potassium as an alternative to lodging control, promoting more sustainable cultivation systems. Theoretical framework: Increasing plant density can promote productivity, rapid soil coverage, reduction of weeds and greater harvest uniformity, reducing the use of pesticides. However, increasing seeding density can promote lodging. Lodging is the phenomenon in which plants leave the vertical position and fall to the ground, affecting the quality of the grains. The commercial product registered to control lodging is highly toxic to the environment. Organomineral sources with potassium and calcium represent an alternative for controlling lodging with reduced environmental impacts. Results: Benefits of increased seeding density to promote grain yield have been found for several crop species, reinforcing the need for adapting seeding density for oat crops. The use trinexapac-ethyl as a growth regulator, it poses risks of phytotoxicity and environmental contamination. In this context, several studies have indicated that potassium and calcium favor cell wall rigidity, potentially contributing to oat stem strength. Originality/value: This study provides significant contribution to the advancement of research on oat in Brazil, bringing new information benefiting farmers, technical assistance agents, and the food industry and improving the production system to ensure food security and care for the environment.

Screening of rhizosphere nitrogen fixing, phosphorus and potassium solubilizing bacteria of Malus sieversii (Ldb.) Roem. and the effect on apple growth

Nitrogen, phosphorus and potassium inorganic fertilizers are commonly used when growing apples, but their excessive application has resulted in a decline in soil fertility and therefore an inability to maintain sustainable cultivation systems. It is possible to compensate for this with biofertilizers. Nitrogen-fixing, phosphorus solubilizing, and potassium solubilizing bacteria are biofertilizers with a broad range of possible uses. In this study, beneficial microorganisms were screened from the rhizosphere soil of the apple tree, Malus sieversii (Ldb.) Roem., which is rich in microbial diversity in natural environments. It was essential to investigate their effects on the growth of apple seedlings. Eight populations of organic phosphorus solubilizing bacteria (56), inorganic phosphorus solubilizing bacteria (13), nitrogen-fixing bacteria (22), and potassium solubilizing bacteria (24) were isolated from eight populations of Xinjiang wild apple rhizosphere in Ili by medium culture. Their morphological characteristics were recorded and their activity was determined. The most active strains were Pseudomonas migulae, Pseudomonas poae, and Pseudomonas extremaustralis, which was determined by physiological and biochemical properties and 16S rDNA sequence analysis. The L16 (45) orthogonal experiment, which used the three strains as testing materials, was created to assess the effects of the strains on apple physiological indicators, soil nutrients, leaf nutrients, and biomass, as well as to identify the ideal combination, concentration, timing, and application method. The results indicated that the peroxidase (POD) and catalase (CAT) activities of apple seedlings increased significantly under the 10 treatment, and the (SOD) activities of the 0 (control) and 1 (inorganic fertilizer only) treatments were significantly lower than the other treatments; soluble sugar, soluble protein and chlorophyll contents increased in all treatments compared to 0 and 1, while malondialdehyde and proline contents increased or decreased compared to 0 and 1; apple seedlings in treatment 10 had the highest soil N, P, and K content, leaf N, P, and K content and biomass were also all highest in treatment 10. In summary, the strains screened for the test can be used as biofertilizers and the optimum application was determined for treatment 10, meaning that the results also provide a theoretical basis for their application in artificially grown orchards.

First observation on tomato plant growth in an innovative soilless sustainable cultivation system in south of Italy

First observation on tomato plant growth in an innovative soilless sustainable cultivation system in south of Italy

Submerged fermentation using Aspergillus tubingensis as an efficient strategy to obtain antioxidant extracts from black cricket proteins

In recent years, there has been growing interest in edible insects as a novel food source due to their high nutritional value and more sustainable cultivation system compared to traditional animal sources. Edible insects are rich in proteins, which can be used to produce bioactive peptides through enzymatic hydrolysis or fermentation. The main objective of this study was to evaluate the production of an antioxidant extract using proteins extracted from the black cricket (Gryllus assimilis) as a substrate for the submerged fermentative process conducted by the filamentous fungus Aspergillus tubingensis. A response surface methodology (CCRD) was employed to investigate the effect of glucose and black cricket protein concentrations in the culture medium on the release of the peptides. The results demonstrated that the maximum values for DPPH (290.79 µmol TE g–1), ABTS (862.82 µmol TE g–1), and FRAP (1020.11 µmol TE g–1) were obtained at 72 or 96 h of fermentation using lower concentrations of both protein and glucose. These findings confirm that black cricket proteins are suitable for producing an antioxidant extract via microbial fermentation.

Conservation Agriculture for Sustainable Agriculture

The paper is centered on the concept of conservation agriculture (CA), which is defined as a sustainable cultivation system for the future. Conservation agriculture (CA) is a sustainable farming system that promotes minimal soil disturbance, permanent soil cover, and crop rotations to maintain soil health and productivity. This approach focuses on maximizing natural resources, reducing inputs, and improving the efficiency of nutrient use. CA practices have been found to reduce soil erosion, conserve water, and increase soil organic matter, leading to improved crop yields and reduced greenhouse gas emissions. In addition to improving agricultural productivity, CA can also contribute to broader sustainable development goals, including poverty reduction, food security, and biodiversity conservation. However, the adoption of CA requires a shift in mindset and significant investment in equipment, training, and research. Conservation agriculture (CA) started in 1930 and it didn’t gain popularity till 1950. But from 1950 to 1990, there was very little rise- CA was practiced in only 2-million-hectare land. From 1990 to 2015, CA was practices in almost 180- million-hectare land with 10-million hectare annually around the world. The places where CA is practiced the most is Brazil, next is America followed by Australia. In India, CA is practiced at 3-million-hectare land in different forms. Various types of machinery and techniques are used in conservation agriculture such as zero tillage, crop diversification and intensification, multi crop zero tillage plant, mechanical transplanter, happy seeder and laser land leveler. The use of machinery in CA has several benefits, including improved soil health, increased crop yields, and reduced labor and input costs. However, the adoption of CA machinery requires significant investment in equipment and training, and there may be limitations in some regions due to soil conditions and crop types. However, promoting CA technologies still faces challenges such as the lack of appropriate seeders for small-scale farmers, competition between CA use and livestock feeding for crop residues, burning of crop residues, a shortage of skilled manpower, and overcoming the traditional mindset about tillage. Drawback of conservation agriculture is Limited adoption, limited knowledge and skills, dependence on herbicide and initial investment costs and so on.

Soil carbon and nitrogen sequestration and associated influencing factors in a sustainable cultivation system of fruit trees intercropped with cover crops

We comprehensively quantified the influence of cover crops on soil carbon and nitrogen storage in Chinese orchards by a meta-analysis based on the literature published during 1990 to 2020. The factors influencing soil carbon and nitrogen storage were also analyzed. The results showed that compared with clean tillage, soil carbon and nitrogen storage under the cultivation of cover crops considerably increased by 31.1% and 22.8%, respectively. Intercropping legumes enhanced soil organic carbon storage by 4.0% and total nitrogen storage by 3.0% compared with non-legumes. The effect of mulching duration was most prominent at 5-10 years, with 58.5% and 32.8% increases in soil carbon and nitrogen storage, respectively. The largest increase in soil carbon and nitrogen storage (32.3% and 34.1%, respectively) occurred in areas with low initial organic carbon (<10 g·kg-1) and total nitrogen (<1.0 g·kg-1). In addition, suitable mean annual temperature (10-13 ℃) and precipitation (400-800 mm) markedly contributed to soil carbon and nitrogen storage in the middle and lower reaches of the Yellow River. The findings indicated that multiple factors influence the synergistic changes in soil carbon and nitrogen storage in orchards, while intercropping with cover crops is an effective strategy for enhancing soil carbon and nitrogen sequestration.

Development of economical and sustainable cultivation system for biomass production and simultaneous treatment of municipal wastewater using Tetraselmis indica BDUG001

ABSTRACT Microalgal-based bioprocess offers several advantages including wastewater reclamations, therefore present study assessed the usability of the combination of untreated municipal sewage wastewater (UTMSWW) and secondary treated municipal sewage wastewater (STSWW) for nutrient removal and recovery by Tetraselmis indica (T. indica) BDUG001. The present study optimized the additional nutrient supplementations (e.g. ASN-III) percentage and day-night cycle, pH and pH with aeration for monitoring high-rate biomass production and nutrient recovery. The study results showed that the combination of 75% UTMSWW + 25% ASN-III supported maximum biomass production (2.65 ± 0.07 g/L). In the optimized day-night cycle (12:12 h), T. indica BDUG001 showed improved biomass production (2.75 ± 0.07 g/L), biomass productivity (165.63 ± 4.42 mg/L/d), and photosynthetic pigments production. Under optimized pH∼ 7.0 with aeration, maximum total nitrate (TN) removal efficiency (87.67 ± 3.08–91.55 ± 1.92%) was observed, while COD and TP removal was maximum at pH ∼ 9.0. The maximum biomass production (2.35 ± 0.07–2.77 ± 0.04 g/L) with biomass productivity (93.75 ± 167.19 ± 2.21 mg/L/d) and lipid content (42.98 ± 1.86–47.85 ± 0.21% DCW) were also at pH 7.0. with aeration. The present study verified the utilization of UTMSWW with the combination of conventional medium, optimized day-night cycle, pH with aeration along with designing low-cost PBR. It was the ideal system for the cultivation of T. indica BDUG001 for the recovery of nutrients from wastewater, production of biofuels and value-added feedstock.

Application of humic acid and biofertilizers changes oil and phenolic compounds of fennel and fenugreek in intercropping systems

The study investigated the effect of organic/biofertilizers in intercropping patterns on seed yield and yield components and essential oil, fatty acid, and phenolic compounds of fennel (Foeniculum vulgare L.) and fenugreek (Trigonella foenum-graecum L.). Experimental treatments included the application of humic acid (HA), biofertilizers (BFS), and the unfertilized control in five planting patterns [1 row fennel + 2 rows fenugreek intercropping (1F:2FG), 2 rows fennel + 2 rows fenugreek intercropping (2F:2FG), 2 rows fennel + 4 rows fenugreek intercropping (2F:4FG), and sole cropping of each species]. Sole cropping with BFS produced the highest seed yields for fennel (2233 kg ha−1) and fenugreek (1240 kg ha–1). In contrast, the 2F:2FG intercropping ratio with BFS yielded the maximum fixed oil content for fennel (17.4%) and fenugreek (8.3%). Application of HA and BFS enhanced oil yields by 66% and 75% in fennel and 40% and 57% in fenugreek, respectively. The 2F:2FG intercropping ratio with BFS produced the maximum essential oil constituents [(E)-anethole, estragole, and fenchone] in fennel. In addition, 2F:4FG with BFS and 1F:1FG with HA produced the highest unsaturated fatty acid (oleic and linoleic acids) concentration in both species. The 2F:2FG intercropping ratio with BFS and HA produced the highest chlorogenic acid and quercetin contents, respectively, in fennel. In contrast, the 2F:4FG intercropping ratio with HA produced the highest chlorogenic acid and caffeic acid contents in fenugreek. Intercropping fennel/fenugreek with BFS or HA improved the essential oil content (fennel only), fixed oil quality and quantity, and phenolic compounds and created a more sustainable cultivation system than sole cropping systems for both species under low-input conditions.

Effects of water recirculation on microalgae assemblage and corresponding sustainability of the photobioreactor cultivation system

An algae photobioreactor (APB) was used to determine the effect of water recirculation on the growth of algal assemblage. CO2 in the flue gas from a power plant was the carbon source. Boiler water was used as the source water. The results showed that microalgae cultivation under recirculation conditions was stable over a period of four months. Biomass productivities during the 1st through 4th months of recirculation (0.26, 0.23, 0.20, and 0.18 g L−1 d−1, respectively) were not significantly different than freshwater (0.22 g L −1 d −1). Furthermore, the relationship between eukaryotic and bacterial domains in the assemblage remained consistent throughout the four months of recirculation (80.7, 87.1, 83.1, and 82.1%, respectively, and 19.2, 12.8, 16.9, and 17.8%, respectively). This was not significantly different than the abundance of each domain in the control freshwater cultivation (83.7% eukaryotic and 16.2% bacterial). A 1 m3 photobioreactor was then envisioned for a mass, energy, and exergy analysis to evaluate the water recirculation on sustainability of the culture system. The mass balance analysis concluded that 98% reduction in water usage, 25% reduction in nitrogen, and 12.5% reduction in phosphorus could be achieved during cultivation operating under recirculation for one year, while maintaining biomass productivity of 1.2 kg wet algal biomass and sequestration of 0.4 kg CO2 per day. The exergy balance analysis concluded that without considering solar irradiation, the culture with water recirculation greatly enhanced the rational exergy efficiency, which represents a more sustainable cultivation system for CO2 capture and utilization.

Temperature ranges for survival and growth of juvenile Saccharina sculpera (Laminariales, Phaeophyta) and applications for field cultivation

Saccharina sculpera is highly valued for human consumption and value-added products. However, natural resources of this kelp have decreased sharply and it is in danger of extinction. Resources recovery through cultivation is being trialed to enable the sustainable use of this species. In this study, the temperature range for survival and optimal growth of juvenile S. sculpera was identified and applied to field cultivation. This study investigated the survival and growth of juvenile S. sculpera under six temperatures (i.e., 5, 10, 15, 16, 18, and 20°C) and two light intensities (i.e., 20 and 40 μmol photons m-2 s-1) in an indoor culture experiment. In these experiments, the blade length decreased at 16°C under the both light intensities. The thalli died at 20°C and 20 μmol photons m-2 s-1, and at 18‒20°C and 40 μmol photons m-2 s-1. During the field cultivation, early growth of S. sculpera was highest at the 5 m depth and growth decreased as the water depth increased. When the initial rearing depth was maintained without adjustment throughout the cultivation period (from December to October), all the cultivated S. sculpera plants died during August and September. However, S. sculpera plants lowered from 5 to 15 m and grew to 90.8 ± 13.1 cm in July. The seawater temperature at 15 m depth was similar to the upper level of thermal tolerance demonstrated by juvenile S. sculpera in the indoor culture experiments (16°C or lower). The plants were subsequently lowered to 25 m depth in August, which eventually led to their maturation in October. The present study confirmed that improved growth rates and a delay in biomass loss can be achieved by adjusting the depth at which the seaweeds are grown during the cultivation period. These results will contribute to the establishment of sustainable cultivation systems for S. sculpera.

Genome wide association mapping for agronomic, fruit quality, and root architectural traits in tomato under organic farming conditions

BackgroundOpportunity and challenges of the agriculture scenario of the next decades will face increasing demand for secure food through approaches able to minimize the input to cultivations. Large panels of tomato varieties represent a valuable resource of traits of interest under sustainable cultivation systems and for genome-wide association studies (GWAS). For mapping loci controlling the variation of agronomic, fruit quality, and root architecture traits, we used a heterogeneous set of 244 traditional and improved tomato accessions grown under organic field trials. Here we report comprehensive phenotyping and GWAS using over 37,300 SNPs obtained through double digest restriction-site associated DNA (dd-RADseq).ResultsA wide range of phenotypic diversity was observed in the studied collection, with highly significant differences encountered for most traits. A variable level of heritability was observed with values up to 69% for morphological traits while, among agronomic ones, fruit weight showed values above 80%. Genotype by environment analysis highlighted the strongest genotypic effect for aboveground traits compared to root architecture, suggesting that the hypogeal part of tomato plants has been a minor objective for breeding activities. GWAS was performed by a compressed mixed linear model leading to 59 significantly associated loci, allowing the identification of novel genes related to flower and fruit characteristics. Most genomic associations fell into the region surrounding SUN, OVATE, and MYB gene families. Six flower and fruit traits were associated with a single member of the SUN family (SLSUN31) on chromosome 11, in a region involved in the increase of fruit weight, locules number, and fruit fasciation. Furthermore, additional candidate genes for soluble solids content, fruit colour and shape were found near previously reported chromosomal regions, indicating the presence of synergic and multiple linked genes underlying the variation of these traits.ConclusionsResults of this study give new hints on the genetic basis of traits in underexplored germplasm grown under organic conditions, providing a framework for the development of markers linked to candidate genes of interest to be used in genomics-assisted breeding in tomato, in particular under low-input and organic cultivation conditions.

Effect of Seed Dressing and Soil Chemical Properties on Communities of Microorganisms Associated with Pre-Emergence Damping-Off of Broad Bean Seedlings

Combating soil pathogens that disable plant emergence is among the most difficult challenges of global agriculture. Legumes, preferred in sustainable cultivation systems, are particularly sensitive to pre-emergence damping-off of seedlings. Seed dressing is therefore a very important element in the cultivation technology. The aim of this study was to compare the impact of biological (Pythium oligandrum) and chemical (carboxin + thiuram) seed dressing on the quantitative and qualitative composition of microorganisms participating in the epidemiology of this disease, under specific hydrothermal conditions and chemical properties of the soil (pH, humus, macro-, and micronutrient). Microorganism identification was done using the MALDI-TOF MS (Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry) technique. Species were assigned to frequency groups, and populations of pathogens, saprophytes, and antagonists were identified. The biodiversity of these communities was expressed with Simpson’s Reciprocal, Shannon–Wiener, and Evenness (Shannon) indices. In individual variants of seed pre-treatment, the correlations between individual edaphic factors and the suppression of pre-emergence damping-off, the number of isolates obtained from infected seedlings, and the share of individual trophic groups of fungi were assessed. The main causes of pre-emergence damping-off of broad bean seedlings are Ilyonectria destructans, Globisporangium irregulare, Fusarium equiseti, Rhizoctonia solani, and Fusarium solani. Eliminating seed treatment results in a seedling mortality rate of 33.5–42.5%. The effectiveness of the chemical protection product is 44.2% and 25.9%. Carboxin and thiuram reduce the diversity of microorganisms involved in the pathogenesis of pre-emergence damping-off and limit the presence of antagonistic fungi. Under the influence of P. oligandrum, there was a five-fold increase in the population of antagonists. An increase in humus in the soil reduces the percentage of diseased broad bean seedlings.

Evaluation of Lettuce (Lactuca sativa L.) Production under Hydroponic System: Nutrient Solution Derived from Fish Waste vs. Inorganic Nutrient Solution

Organic fresh products are appreciated and are gaining a good reputation regarding human health and environmental concerns. Despite the fact that hydroponics are commonly used in vegetable production, growers are looking for sustainable cultivation systems. Therefore, the objective of this study was to investigate the effect of using an organic-based nutrient solution (NS) derived from fish waste in a hydroponic system on the vegetative growth and production of lettuce compared to a conventional inorganic NS. Plant growth, yield, physiological and nutrient content parameters were determined. The results revealed that the overall growth and fresh biomass of the organic NS grown lettuce were relatively lower than those of the inorganic NS. Stomata density was significantly higher in inorganic grown lettuce compared to the organic one. However, the total chlorophyll, carotene, phenolic compounds, and flavonoid contents, as well as antioxidant activity were significantly higher in lettuce grown in organic NS compared to the inorganic one. Leaf nutrient content at harvest was significantly impacted by the type of used fertilizer. Based on these findings, in hydroponic system, organic liquid fertilizer derived from fish waste (as an alternative NS source) requires further improvements to achieve optimal growth and yield comparable to that of conventional inorganic NS.

The Growth of Leaf Lettuce and Bacterial Communities in a Closed Aquaponics System with Catfish

Aquaponics is a circulating and sustainable system that combines aquaculture and hydroponics and forms a symbiotic relationship between fish, plants, and microorganisms. We hypothesized that feed alone could support plant growth, but the symbiosis with fish adds some beneficial effects on plant growth in aquaponics. In this study, we created three closed culture systems, namely, aquaponics, hydroponics without nitrogen (N) and phosphorus (P), and aquaculture, and added the same amount of feed containing N and P to all the treatments in order to test the hypothesis. Accumulation of NO3− and PO43− was alleviated in aquaponics and hydroponics as a result of plant uptake. Lettuce plants grown in aquaponics grew vigorously until 2 weeks and contained a constant level of N in plants throughout the production period, whereas those in hydroponics grew slowly in the early stage and then vigorously after 2 weeks with a late increment of N concentration. These results suggest that catfish help with the faster decomposition of the feed, but, in hydroponics, feed can be slowly dissolved and decomposed owing to the absence of the fish. The bacterial community structures of the culture solution were investigated using 16S rRNA gene amplicon sequencing. At the class level, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria were the major microbial groups in the solutions. Aquaponics prevented the pollution of tank solution and maintained a higher water quality compared with hydroponics and aquaculture, suggesting that aquaponics is a more sustainable cultivation system even in a small-scale system.

Optimizing Intercropping Systems of Black Cumin (Nigella sativa L.) and Fenugreek (Trigonella foenum‐graecum L.) through Inoculation with Bacteria and Mycorrhizal Fungi

AbstractThis study evaluates the effects of intercropping patterns, plant growth‐promoting rhizobacteria and arbuscular mycorrhizal fungi (AMF) on seed yield and yield components of black cumin (Nigella sativa L.) and fenugreek (Trigonella foenum‐graecum L.), as well as the essential oil and fatty acid profile of black cumin. A two‐year two‐factorial field experiment was conducted in 2015 and 2016 to investigate intercropping of black cumin and fenugreek in five ratios and biofertilizer application as AMF and bacteria. Intercropping reveals higher concentrations of nitrogen and phosphorus compared with monocropping, whereas monocropping inoculated with bacteria shows the highest seed yield of both fenugreek (151 g m−2) and black cumin (148 g m−2). Regarding the quality of black cumin, the combination of a black cumin:fenugreek‐intercropping pattern of 66:34 with bacteria fertilization is most promising, as it shows i) the maximum essential oil content, oil yield, and fixed oil content, ii) the highest contents of thymol and p‐cymene, iii) the highest content of linoleic acid, and iv) the maximum land equivalent ratio. Conclusively, bacteria fertilization and black cumin:fenugreek‐intercropping pattern of 66:34 helps improving essential oil, fixed oil quality, and quantity of black cumin, thus creating a more sustainable cultivation system for black cumin and fenugreek.

Propagation and ex-situ conservation of Lomelosia minoana subsp. minoana and Scutellaria hirta - two ornamental and medicinal Cretan endemics (Greece)

Human needs and concomitant commercial trade to date trigger the demand of new ornamental plants and new natural medicinal products. The current study includes preliminary seed germination trials and presents the development of effective vegetative propagation protocols for Lomelosia minoana subsp. minoana (Dipsacaceae) and Scutellaria hirta (Lamiaceae), both globally rare, local endemics of Crete (Greece) with potential ornamental and medicinal value. Based on material collected directly from the wild, seed germination was succeeded (38%, T50: 10.74) only for L. minoana subsp. minoana. The optimal indole-3-butyric acid concentrations for effective rooting of cuttings were 2000 mg L-1 for L. minoana subsp. minoana (85%) and 4000 mg L-1 for S. hirta (50%). Seasonal differences were observed in respective rooting rates of the studied taxa. The detected rooting rates for L. minoana subsp. minoana cuttings are above standards to allow possible commercial application in the ornamental industry. Although the detected rooting rate (50%) for S. hirta was adequate for its ex situ conservation, it seems almost marginal for future commercial application and further investigation is needed. The sustainable utilization of these Cretan endemics studied herein provides new input for the ornamental-horticultural and cosmetic-pharmaceutical industries. This study shows how rare and endemic wild plant species can be progressively domesticated and introduced into sustainable cultivation systems in order to avoid the depletion of unique phytogenetic resources.

Seriola lalandi cultivated on integrated system with water recirculation and photovoltaic energy in the coastal area of Atacama desert

ABSTRACT An integrated recirculation aquaculture system (RAS) was designed and developed using bacteria, echinoderms (Athyonidium chilensis), and mollusks (Mytilus chilensis) to maintain water quality. Photovoltaic panels were employed to reduce the energy costs of the crop. The evaluation of survival and growth of adults (2-month olds) and juveniles (7-month olds) of Seriola lalandi fish, fed with commercial pellets, was carried out. Different water parameters (temperature, humidity, irradiance, oxygen, pH, ammonium, nitrite, nitrate, etc.) were recorded. The distribution of trophic levels maintained the quality of the water in the system. The photovoltaic panels allowed autonomy of 4 h of disconnection from the electrical network. The weight gain was optimal in adults for the species (initial 1496 g, final 1698 g) and juveniles (initial 24 g, final 588 g). The survival of 100% of adults and 39% of juveniles was documented. The analysis of the fillet helped ascertain its quality for human consumption. This cultivation system depended only on a reservoir to supply water. Operating the system does not require highly specialized personnel and the use of biofilters/photovoltaic panels reduces operating costs. Finally, the production of commercially important marine organisms in efficient and sustainable cultivation systems may help solve global challenges such as the availability of food.

Implications of Bioenergy Cropping for Soil: Remote Sensing Identification of Silage Maize Cultivation and Risk Assessment Concerning Soil Erosion and Compaction

Energy transition strategies in Germany have led to an expansion of energy crop cultivation in landscape, with silage maize as most valuable feedstock. The changes in the traditional cropping systems, with increasing shares of maize, raised concerns about the sustainability of agricultural feedstock production regarding threats to soil health. However, spatially explicit data about silage maize cultivation are missing; thus, implications for soil cannot be estimated in a precise way. With this study, we firstly aimed to track the fields cultivated with maize based on remote sensing data. Secondly, available soil data were target-specifically processed to determine the site-specific vulnerability of the soils for erosion and compaction. The generated, spatially-explicit data served as basis for a differentiated analysis of the development of the agricultural biogas sector, associated maize cultivation and its implications for soil health. In the study area, located in a low mountain range region in Western Germany, the number and capacity of biogas producing units increased by 25 installations and 10,163 kW from 2009 to 2016. The remote sensing-based classification approach showed that the maize cultivation area was expanded by 16% from 7305 to 8447 hectares. Thus, maize cultivation accounted for about 20% of the arable land use; however, with distinct local differences. Significant shares of about 30% of the maize cultivation was done on fields that show at least high potentials for soil erosion exceeding 25 t soil ha−1 a−1. Furthermore, about 10% of the maize cultivation was done on fields that pedogenetically show an elevated risk for soil compaction. In order to reach more sustainable cultivation systems of feedstock for anaerobic digestion, changes in cultivated crops and management strategies are urgently required, particularly against first signs of climate change. The presented approach can regionally be modified in order to develop site-adapted, sustainable bioenergy cropping systems.

An integrated plant nutrition system (IPNS) for corn in the Mid-Atlantic USA

Current trends in agriculture have moved toward more sustainable cultivation systems with higher efficiency of input use. A variety of materials, derived from different resources, can serve as a crop nutrient sources. An Integrated Plant Nutrition System (IPNS) uses the combined and harmonious use of inorganic, organic and biological nutrient resources to maximize efficiency of inputs. We evaluated the effects of commercial nitrogen (N) fertilizer, humic acid compounds (HA), compost/manure teas and bioinoculants as inorganic, organic and biological resources, respectively and their synergy over three years on corn (Zea mays L.) in the Mid-Atlantic USA. The individual and combined application of HA and biofertilizer following the IPNS influenced corn height and leaf greenness to varying degrees, most likely due to biostimulant effects. In 2017, corn height, NDVI, greenness and vigor responded positively to biostimulant application to varying magnitudes and growth stages, however grain yield and nutrient content were not affected. In combined studies from 2018 and 2019 corn height was not impacted by biostimulant application but NDVI, photosynthetic efficiency, greenness and vigor were increased at different doses and corn growth stages. The combined use of HA + biofertilizer (Microlife Humic + Microgeo) was the only treatment leading to increased grain yield. This study demonstrates that the individual and combined application of HA and biofertilizer can influence corn growth and vigor at various points during the growing season. However, the current study cannot conclusively confirm that the integrated use of HA and biofertilizers (IPNS) is a better practice than the application of each compound individually.