Long-term conservation tillage with reduced nitrogen fertilization intensity can improve winter wheat health via positive plant-microorganism feedback in the rhizosphere.

Microbiome-based solutions are regarded key for sustainable agroecosystems. However, it is unclear how agricultural practices affect the rhizosphere microbiome, plant-microorganism interactions and crop performance under field conditions. Therefore, we installed root observation windows in a winter wheat field cultivated either under long-term mouldboard plough (MP) or cultivator tillage (CT). Each tillage practice was also compared at two nitrogen (N) fertilization intensities, intensive (recommended N-supply with pesticides/growth regulators) or extensive (reduced N-supply, no fungicides/growth regulators). Shoot biomass, root exudates and rhizosphere metabolites, physiological stress indicators, and gene expression were analyzed together with the rhizosphere microbiome (bacterial/archaeal 16S rRNA gene, fungal ITS amplicon, and shotgun metagenome sequencing) shortly before flowering. Compared to MP, the rhizosphere of CT winter wheat contained more primary and secondary metabolites, especially benzoxazinoid derivatives. Potential copiotrophic and plant-beneficial taxa (e.g. Bacillus, Devosia, and Trichoderma) as well as functional genes (e.g. siderophore production, trehalose synthase, and ACC deaminase) were enriched in the CT rhizosphere, suggesting that tillage affected belowground plant-microorganism interactions. In addition, physiological stress markers were suppressed in CT winter wheat compared to MP. In summary, tillage practice was a major driver of crop performance, root deposits, and rhizosphere microbiome interactions, while the N-fertilization intensity was also relevant, but less important.

Cannabis Hunger Games: nutrient stress induction in flowering stage - impact of organic and mineral fertilizer levels on biomass, cannabidiol (CBD) yield and nutrient use efficiency.

Indoor medicinal cannabis cultivation systems enable year-round cultivation and better control of growing factors, however, such systems are energy and resource intensive. Nutrient deprivation during flowering can trigger nutrient translocation and modulate the production of cannabinoids, which might increase agronomic nutrient use efficiency, and thus, a more sustainable use of fertilizers. This experiment compares two fertilizer types (mineral and organic) applied in three dilutions (80, 160 and 240 mg N L-1) to evaluate the effect of nutrient deprivation during flowering on biomass, Cannabidiol (CBD) yield and nutrient use efficiency of N, P and K. This is the first study showing the potential to reduce fertilizer input while maintaining CBD yield of medicinal cannabis. Under nutrient stress, inflorescence yield was significantly lower at the final harvest, however, this was compensated by a higher CBD concentration, resulting in 95% of CBD yield using one-third less fertilizer. The higher nutrient use efficiency of N, P, and K in nutrient-deprived plants was achieved by a larger mobilization and translocation of nutrients increasing the utilization efficiency of acquired nutrients. The agronomic nutrient use efficiency of CBD yield - for N and K - increased 34% for the organic fertilizers and 72% for the mineral fertilizers comparing the dilution with one-third less nutrients (160) with the highest nutrient concentration (240). Differences in CBD yield between fertilizer types occurred only at the final harvest indicating limitations in nutrient uptake due to nutrient forms in the organic fertilizer. Our results showed a lower acquisition and utilization efficiency for the organic fertilizer, proposing the necessity to improve either the timing of bio-availability of organic fertilizers or the use of soil amendments.

Biofortification of Broccoli Microgreens (Brassica oleracea var. italica) with Glucosinolates, Zinc, and Iron through the Combined Application of Bio- and Nanofertilizers.

There is a severe need to develop a sustainable, affordable, and nutritious food supply system. Broccoli microgreens have attracted attention due to their rich nutritional content and abundant bioactive compounds, constituting an important opportunity to feed the ever-increasing population and fight global health problems. This study aimed to measure the impact of the combined application of biofertilizers and zinc and iron nanofertilizers on plant growth and the biofortification of glucosinolates (GLSs) and micronutrients in broccoli microgreens. Biofertilizers were based on plant growth-promoting (PGP) bacterial consortia previously isolated and characterized for multiple PGP traits. Nanofertilizers consisted of ZnO (77 nm) and γ-Fe2O3 (68 nm) nanoparticles synthesized with the coprecipitation method and functionalized with a Pseudomonas species preparation. Treatments were evaluated under seedbed conditions. Plant growth parameters of plant height (37.0-59.8%), leaf diameter (57.6-81.1%) and fresh weight (112.1-178.0%), as well as zinc (122.19-363.41%) and iron contents (55.19-161.57%), were mainly increased by nanoparticles subjected to the functionalization process with Pseudomonas species and uncapped NPs applied together with the biofertilizer treatment. Regarding GLSs, eight compounds were detected as being most positively influenced by these treatments. This work demonstrated the synergistic interactions of applying ZnO and γ-Fe2O3 nanofertilizers combined with biofertilizers to enhance plant growth and biofortify micronutrients and glucosinolates in broccoli microgreens.

Compost and Phosphorus/Potassium-Solubilizing Fungus Effectively Boosted Quinoa's Physio-Biochemical Traits, Nutrient Acquisition, Soil Microbial Community, and Yield and Quality in Normal and Calcareous Soils.

Calcareous soil had sufficient phosphorus and potassium (PK) in different forms due to the high contents of PK-bearing minerals; however, the available PK state was reduced due to its PK-fixation capacity. Compost, coupled with high PK solubilization capacity microbes, is a sustainable solution for bioorganic fertilization of plants grown in calcareous soil. A 2-year field experiment was conducted to investigate the effect of compost (20 t ha-1) with Aspergillus niger through soil drenching (C-AN) along with partial substitution of PK fertilization on quinoa performance in normal and calcareous soils. Treatments included PK100% (72 kg P2O5 ha-1 + 60 kg K2O ha-1 as conventional rate), PK100%+C-AN, PK75%+C-AN, PK50%+C-AN, PK25%+C-AN, and only C-AN in normal and calcareous soils. Results showed that C-AN and reduced PK fertilization (up to 75 or 50%) increased photosynthetic pigments and promoted nutrient acquisition in quinoa grown in calcareous soil. Reduced PK fertilization to 75 or 50% plus C-AN in calcareous soil increased osmoprotectants, nonenzymatic antioxidants, and DPPH scavenging activity of quinoa's leaves compared to the PK0%+C-AN treatment. The integrative application of high PK levels and C-AN enhanced the quinoa's seed nutritional quality (i.e., lipids, carbohydrates, mineral contents, total phenolics, total flavonoids, half maximal inhibitory concentration, and antiradical power) in calcareous soil. At reduced PK fertilization (up to 75 or 50%), application of compost with Aspergillus niger through soil drenching increased plant dry weight by 38.7 or 53.2%, hectoliter weight by 3.0 or 2.4%, seed yield by 49.1 or 39.5%, and biological yield by 43.4 or 33.6%, respectively, compared to PK0%+C-AN in calcareous soil. The highest P-solubilizing microorganism's population was found at PK0%+C-AN in calcareous soil, while the highest Azotobacter sp. population was observed under high PK levels + C-AN in normal soil. Our study recommends that compost with Aspergillus niger as a bioorganic fertilization treatment can partially substitute PK fertilization and boost quinoa's tolerance to salt calcareous-affected soil.

The Influence of Bacteria-Inoculated Mineral Fertilizer on the Productivity and Profitability of Spring Barley Cultivation.

The heavy use of mineral fertilizers causes imbalances in the biological processes that take place in soil. Therefore, it is necessary to develop more effective fertilizers or fertilizer complexes that ensure agricultural productivity and soil conservation. There is currently a lack of knowledge regarding the effectiveness of biologically enriched, complex mineral fertilizers for spring barley fertilization. The hypothesis of this study was that bacteria-enriched (Paenibacillus azotofixans, Bacillus megaterium, Bacillus mucilaginosus, and Bacillus mycoides), complex mineral fertilizers (N5P20.5K36) have significant impacts on the yield and potential for economic use of spring barley. Experimental studies were carried out for three years (2020-2022) with sandy loam soil in southern Lithuania. Four different spring barley fertilization scenarios (SCs) were investigated. In SC-1 (control), complex mineral fertilizer (N5P20.5K36) was not applied. In the other SCs, spring barley was sown with a drill and fertilizers were incorporated locally during the sowing operation: fertilization scenario SC-2 used 300 kg ha-1, SC-3 used 150 kg ha-1 preceded by a bacteria-inoculated complex mineral fertilizer (N5P20.5K36), and SC-4 used 300 kg ha-1 with the same bacterial complex. The results showed that the bacterial inoculant increased the efficiency of the mineral fertilizer and had an effect on plant growth in barley. For three consecutive years in the same plots, the bacterial inoculant showed significant positive effects on grain yield (changes of 8.1% in 2020, 6.8% in 2021, and 17.3% in 2022 between SC-2 and SC-4). Comparing the several different fertilizer scenarios from an economic point of view, it was observed that the highest profit per hectare was obtained with SC-4 in all three years of the study. Comparing SC-4 and SC-2, an increase of 13.7% was observed in 2020, followed by 9.1% and 41.9% in 2021 and in 2022, respectively. This study will be useful for farmers, biological inoculant manufacturers, and scientists researching the effectiveness of biological inoculants for growing agricultural crops. We found that it is possible to increase the yield of barley (7-17%) using the same rate of mineral fertilization by enriching it with bacterial inoculants. Further studies should be conducted to determine the effects of the bacterial inoculant on crop yield and soil over a period longer than 3 years.

The Effect of Spring Barley Fertilization on the Content of Polycyclic Aromatic Hydrocarbons, Microbial Counts and Enzymatic Activity in Soil.

Soil-dwelling microorganisms play an important role in the environment by decomposing organic matter, degrading toxic compounds and participating in the nutrient cycle. The microbiological properties of soil are determined mainly by the soil pH, granulometric composition, temperature and organic carbon content. In agricultural soils, these parameters are modified by agronomic operations, in particular fertilization. Soil enzymes participate in nutrient cycling and they are regarded as sensitive indicators of microbial activity and changes in the soil environment. The aim of the present study was to determine whether PAH content in soil is associated with the microbial activity and biochemical properties of soil during the growing season of spring barley treated with manure and mineral fertilizers. Soil samples for analysis were collected on four dates in 2015 from a long-term field experiment established in 1986 in Balcyny near Ostróda (Poland). The total content of PAHs was lowest in August (194.8 µg kg-1) and highest in May (484.6 µg kg-1), whereas the concentrations of heavier weight PAHs was highest in September (158.3 µg kg-1). The study demonstrated that weather conditions and microbial activity induced considerable seasonal variations in PAHs content. Manure increased the content of organic carbon and total nitrogen, the abundance of organotrophic, ammonifying and nitrogen-fixing bacteria, actinobacteria and fungi and enhanced the activity of soil enzymes, including dehydrogenases, catalase, urease, acid phosphatase and alkaline phosphatase.

Impact of Crop Sequence and Fertilization on Potato Yield in a Long-Term Study.

The research was conducted during the years 2007-2013, on the base of a long-term study established in 1958, at the Experimental Station Brody (52°26' N; 16°18' E), belonging to the Poznan University of Life Sciences. Varieties of potatoes resistant to cyst nematodes were grown in a seven-course crop rotation (potato-spring barley-alfalfa-alfalfa-spring oilseed rape-winter wheat-winter rye) and in continuous monoculture. The presented study from the years 2007-2013 covers the next 8th rotation of the 7-field crop rotation (since 1958). With regard to continuous cultivation, this is the period between the 50th and 56th year of the potato monoculture. The experiment included 11 fertilization variants, of which the following 7 were included in the study: 1-control object without fertilization, 2-manure, 3-manure + NPK, 4-NPKCa, 5-NPK, 6-NP, 7-NK and 8-PK. Every year, mineral and organic fertilization was applied in the following doses per 1 ha: N-90 kg, P-26 kg, K-100 kg, manure-30 t and Ca-0.7 t. Potato cultivation in monoculture resulted in a significant reduction in tuber yield compared to crop rotation and a reduction in the number of tubers per plant and the average weight of one tuber. Manure fertilization, especially in combination with NPK mineral fertilizer, had a more favorable effect on the level of potato yielding and the content of N, P, K and Mg in tubers compared to only mineral fertilization, but decreased the content of dry matter, starch and Ca. The results of long-term experiment indicate that the most effective in potato cultivation is the combined application of both manure and full mineral fertilization (NPK) with the proper sequence of plants (crop rotation).

Niveles de fertilización con calcio, magnesio y azufre en genotipos de arveja voluble (Pisum sativum L.) en Nariño

Nariño es el principal productor de arveja de Colombia. En su cultivo, se fertiliza con nitrógeno, fósforo y potasio, pero no se conoce el efecto de otros nutrimentos. Esta investigación tuvo como objetivo evaluar el efecto de diferentes niveles de calcio, magnesio y azufre sobre los componentes de rendimiento de arveja voluble, en los municipios de Gualmatán, Pupiales y Puerres, en suelos Andisoles y, en Ipiales y Potosí, en suelos Inceptisoles. En cada localidad, se utilizó un diseño de bloques completos al azar, con arreglo en parcelas divididas y tres repeticiones, donde el factor A correspondió a cinco genotipos de arveja y el factor B, a cinco niveles de fertilización con calcio, magnesio y azufre. Los resultados indicaron respuesta positiva de los rendimientos a la aplicación de estos elementos. El nivel de fertilización 112,5-50-25 kg.ha-1 de Ca, Mg y S, respectivamente, presentó mayor rendimiento que el nivel establecido por la información del análisis de suelos o testigo en Gualmatán, Pupiales y Potosí, mientras que, en Puerres, hubo respuesta al nivel más alto, 135-60-30, de los mismos elementos. Los otros niveles de fertilización fueron similares al testigo. En Ipiales, la variedad Sureña presentó rendimientos similares para todos los niveles de fertilización. San Isidro presentó su mayor rendimiento, con el nivel 112,5-50-25 kg.ha-1, de calcio magnesio y azufre. Las líneas con gen afila L3 y L18 igualaron los rendimientos de las variedades comerciales Sureña, Alcalá y San Isidro, en Potosí y en Pupiales.

Nariño is the main pea producer in Colombia. The crop is fertilizer with nitrogen, phosphorus, and potassium, but the effect of other nutrients is unknown. The objective of this research was to evaluate the effect of different levels of calcium, magnesium, and sulfur on the performance components of voluble pea in the municipalities of Gualmatán, Pupiales, and Puerres on Andisols, and in Ipiales and Potosí on Inceptisols soils. A randomized complete block design was used with divided plots and three replications, where factor A corresponded to five pea genotypes and factor B to five levels of fertilization with calcium, magnesium, and sulfur. The results indicated positive response of the yields to the application of these elements. The level of fertilization 112.5-50-25 kg.ha-1 of Ca, Mg, and S respectively, presented a higher yield than the level established by information from the soil analysis or control in Gualmatán, Pupiales and Potosí, while in Puerres there was a response at the highest level 135-60-30 of the same elements. The other levels of fertilization were similar to the control. In Ipiales Sureña variety presented similar yields for all fertilization levels. San Isidro presented its highest yield with a level of 112.5-50-25 kg.ha-1 of calcium, magnesium and sulfur. The lines with the L3 and L18 genes matched the yield of the commercial varieties Sureña, Alcalá and San Isidro in Potosí and Pupiales.

The Influence of Crops on the Content of Polycyclic Aromatic Hydrocarbons in Soil Fertilized with Manure and Mineral Fertilizers.

Polycyclic aromatic hydrocarbons (PAHs) are mainly accumulated in soil. Plants secrete enzymes that transform or biodegrade PAHs in soil. Some plant species are more effective in stimulating the biodegradation of these pollutants than other species. This study was undertaken to evaluate the influence of crop rotation on PAH concentrations in soil. Four crops were grown in rotation: sugar beets, spring barley, maize, and spring wheat. Soil samples for the study were obtained from a long-term field experiment established in 1986 in Balcyny, Poland. The concentrations of PAHs were analyzed in soil samples gathered over a period of 12 years (1998-2009). An attempt was made to evaluate the effect of crop rotation (sugar beets, spring barley, maize, and spring wheat) on PAH concentrations in soil. The content of PAHs in soil samples was measured by gas chromatography with flame ionization detection. Data were processed statistically by repeated measures ANOVA. The concentrations of ∑16 PAHs were lowest in soil after sugar beet cultivation, and highest in soil after maize cultivation. It can be concluded that maize was the plant with the greatest adverse effect on the content of heavy PAH in the soil, a completely different effect can be attributed to spring wheat, which has always been shown to reduce the content of heavy PAH in the soil. Weather conditions affected PAHs levels in soil, and PAH content was highest in soil samples collected in a year with the driest growing season. This arrangement suggests a greater influence of weather conditions than of the cultivated plant.

Long-Term Fertilization Strategy Impacts Rhizoctonia solani-Microbe Interactions in Soil and Rhizosphere and Defense Responses in Lettuce.

The long-term effects of agricultural management such as different fertilization strategies on soil microbiota and soil suppressiveness against plant pathogens are crucial. Therefore, the suppressiveness of soils differing in fertilization history was assessed using two Rhizoctonia solani isolates and their respective host plants (lettuce, sugar beet) in pot experiments. Further, the effects of fertilization history and the pathogen R. solani AG1-IB on the bulk soil, root-associated soil and rhizosphere microbiota of lettuce were analyzed based on amplicon sequencing of the 16S rRNA gene and ITS2 region. Organic fertilization history supported the spread of the soil-borne pathogens compared to long-term mineral fertilization. The fertilization strategy affected bacterial and fungal community composition in the root-associated soil and rhizosphere, respectively, but only the fungal community shifted in response to the inoculated pathogen. The potential plant-beneficial genus Talaromyces was enriched in the rhizosphere by organic fertilization and presence of the pathogen. Moreover, increased expression levels of defense-related genes in shoots of lettuce were observed in the soil with organic fertilization history, both in the absence and presence of the pathogen. This may reflect the enrichment of potential plant-beneficial microorganisms in the rhizosphere, but also pathogen infestation. However, enhanced defense responses resulted in retarded plant growth in the presence of R. solani (plant growth/defense tradeoff).

Responses of Diversity and Productivity to Organo-Mineral Fertilizer Inputs in a High-Natural-Value Grassland, Transylvanian Plain, Romania.

Ecosystems with high natural value (HNV) have generally been maintained by agricultural practices and are increasingly important for the ecosystem services that they provide and for their socio-economic impact in the ever-changing context. Biodiversity conservation is one of the main objectives of the European Green Deal, which aims to address biodiversity loss, including the potential extinction of one million species. The aim of this research was to trace the effects of organic and mineral fertilizers on the floristic composition, but also on the number of species, of the grasslands with high biodiversity (HNV) from the Transylvanian Plain, Romania. The experiments were established in 2018 on the nemoral area and analyzed the effect of a gradient of five organic and mineral treatments. Fertilization with 10 t ha-1 manure or N50 P25K25 ensures an increase in yield and has a small influence on diversity, and it could be a potential strategy for the maintenance and sustainable use of HNV grasslands. Each fertilization treatment determined species with indicator value that are very useful in the identification and management of HNV grasslands. The dry matter biomass increases proportionally as the amounts of fertilizer applied increase and the number of species decreases.

Responses of microbial function, biomass and heterotrophic respiration, and organic carbon in fir plantation soil to successive nitrogen and phosphorus fertilization.

Carbon dioxide (CO2) emissions from forest ecosystems originate largely from soil respiration, and microbial heterotrophic respiration plays a critical role in determining organic carbon (C) stock. This study investigated the impacts of successive nitrogen (N) and phosphorus (P) fertilization after 9 years on soil organic C stock; CO2 emission; and microbial biomass, community, and function in a Chinese fir plantation. The annual fertilization rates were (1) CK, control without N or P fertilization; (2) N50, 50 kg N ha-1; (3) N100, 100 kg N ha-1; (4) P50, 50 kg P ha-1; (5) N50P50, 50 kg N ha-1 + 50 kg P ha-1; and (6) N100P50, 100 kg N ha-1 + 50 kg P ha-1. The N100P50 treatment had the highest cumulative soil CO2 emissions, but the CK treatment had the lowest cumulative soil CO2 emissions among all treatments. The declines of soil organic C (SOC) after successive 9-year fertilization were in the order of 100 kg N ha-1 year-1 > 50 kg N ha-1 year-1 > CK. Compared to the CK treatment, successive N fertilization significantly changed soil microbial communities at different application rates and increased the relative gene abundances of glycoside hydrolases, glycosyl transferases, carbohydrate-binding modules, and polysaccharide lyases at 100 kg N ha-1 year-1. Relative to P fertilization alone (50 kg P ha-1 year-1), combined N and P fertilization significantly altered the soil microbial community structure and favored more active soil microbial metabolism. Microbial community and metabolism changes caused by N fertilization could have enhanced CO2 emission from heterotrophic respiration and eventually led to the decrease in organic C stock in the forest plantation soil. KEY POINTS: • N fertilization, alone or with P, favored more active microbial metabolism genes. • 100 kg N ha-1 fertilization significantly changed microbial community and function. • N fertilization led to a "domino effect" on the decrease of soil C stock.

Metadata of agricultural long-term experiments in Europe exclusive of Germany.

Agricultural long-term experiments (LTEs) are an important research infrastructure for agriculture, plant and soil sciences. The aim of this metadata compilation is to make LTEs easier to find and to facilitate networking. LTEs are here defined as agricultural experiments with a minimum duration of 20 years and research in the context of soil and yield. An extensive literature review was conducted to identify LTEs in Europe exclusive of Germany, because Germany's LTEs were published before. Sources were scientific papers as well as other articles, books, trial guides and websites. The following information was searched for and compiled in this dataset, if available: site and name of the LTE, start and end (if appropriate), holding institution, type of land use (e.g. field crops or grassland), research theme, website (if available), participation in networks, measured parameters, farming category (i.e. conventional or organic), size of the LTE area, longitude and latitude of the LTE, experimental setup including factors, treatments, randomization and replication, number of plots, size of the plots, crop rotation, soil type, substrate, texture, literature which was written in the context of the LTE data, and AGROVOC keywords. LTE from the following countries are included: Austria, Belarus, Belgium, Bulgaria, Czech Republic, Denmark, Estonia, Finland, France, Great Britain, Hungary, Italy, Moldova, Norway, Poland, Romania, Serbia, Slovenia, Spain, Sweden, Switzerland, Ukraine. In total, 186 LTEs could be identified. The LTEs were classified according to the following research themes: fertilization, tillage, crop rotation, other. The majority of LTEs have the research theme "fertilization" (n = 125). Thirty LTEs have the research theme "crop rotation", 26 LTEs have the research theme "tillage", and 26 LTEs have "other" research themes. The following networks could be identified: GLTEN (Global long-term experiment network), ILTER (International long-term ecological research), IOSDV (International Organic Nitrogen Fertilization Experiment), NLFT (National Long-term Fertilization Trials, Hungary), RetiBio 2 (Italy). The oldest LTE was set up 1843, but the largest number of LTEs was established in the second half of the 20th century. Most of the LTEs are held by a scientific institution, i.e. 88 LTEs are held by a non-university scientific institution and 81 LTEs are held by a university or university of applied sciences. The link to the holding institution is provided whenever possible to facilitate contacting.

Long-term continuous cropping affects ecoenzymatic stoichiometry of microbial nutrient acquisition: a case study from a Chinese Mollisol.

BACKGROUND: Soil- and plant-produced extracellular enzymes drive nutrient cycling in soils and are assumed to regulate supply and demand for carbon (C) and nutrients within the soil. Thus, agriculture management decisions that alter the balance of plant and supplemental nutrients should directly alter extracellular enzyme activities (EEAs), and EEA stoichiometry in predictable ways. We used a 12-year experiment that varyied three major continuous grain crops (wheat, soybean, and maize), each crossed with mineral fertilizer (WCF, SCF and MCF, respectively) or not fertilized (WC, SC and MC, respectively, as controls). In response, we measured the phospholipid fatty acids (PLFAs), EEAs and their stoichiometry to examine the changes to soil microbial nutrient demand under the continuous cropping of crops, which differed with respect to the input of plant litter and fertilizer. RESULTS: Fertilizer generally decreased soil microbial biomass and enzyme activity compared to non-fertilized soil. According to enzyme stoichiometry, microbial nutrient demand was generally C- and phosphorus (P)-limited, but not nitrogen (N)-limited. However, the degree of microbial resource limitation differed among the three crops. The enzymatic C:N ratio was significantly lower by 13.3% and 26.8%, whereas the enzymatic N:P ratio was significantly higher by 9.9% and 42.4%, in MCF than in WCF and SCF, respectively. The abundances of arbuscular mycorrhizal fungi and aerobic PLFAs were significantly higher in MCF than in WCF and SCF. CONCLUSION: These findings are crucial for characterizing enzymatic activities and their stoichiometries that drive microbial metabolism with respect to understanding soil nutrient cycles and environmental conditions and optimizing practices of agricultural management. © 2021 Society of Chemical Industry.

Lead and Cadmium Transfer Factors and the Contamination of Tomato Fruits (Solanum lycopersicum) in a Tropical Mountain Agroecosystem.

The objectives of this study was to diagnose Cd and Pb contamination in soil and to identify the main factors that contribute to the transfer of these elements to tomato plants and fruits and contamination levels of the fruits in tropical mountain conditions. Contamination of the study area soils by Cd and Pb was verified. This contamination stemmed from the intensive use of agricultural inputs, mainly organic fertilizers and soluble mineral fertilizers. The relief of the terrain and inadequate soil management influenced the spatial distribution of these two metals. The Cd concentration in tomato fruits was very low, but the Pb contamination detected in approximately 80% of the fruit samples was considerably higher than the limits that pose a danger to human health. The translocation of Pb to the tomato fruits was associated with the use of organic fertilizer, mainly poultry litter.

Produção, valor nutritivo e produtividade estimada de leite de pastagens consorciadas de estação fria / Production, nutritive value and estimated milk yield from intercropped pastures of cold season

O objetivo deste trabalho foi avaliar o potencial de produção de leite ha-1 de três consorciações de aveia-preta e leguminosas em detrimento da aveia-preta estreme fertilizada com N mineral. Os tratamentos utilizados foram: aveia-preta + 200kg de N ha-1 (Av+N); aveia-preta + trevo-branco (Av+Tb); aveia-preta + ervilhaca (Av+Er) e aveia-preta + trevo-vermelho (Av+Tv). As espécies foram implantadas em parcelas de 80m2, sob um delineamento de blocos ao acaso com quatro repetições. As amostragens foram realizadas previamente aos cortes, em três oportunidades, e o material foi avaliado quanto à produção de matéria seca, à composição químico-bromatológica (PB, EE, FDN, FDA, CNF, MM, digestibilidade estimada da matéria seca e digestibilidade do FDN em 48 horas) e à produção estimada de leite por área (kg ha-1). Os resultados foram submetidos à análise de variância, e as médias comparadas pelo teste de Tukey a 5% de probabilidade. A composição químico-bromatológica não diferiu entre os tratamentos Av+N e Av+Er em nenhum dos atributos avaliados. O tratamento Av+N proporcionou maior produção de leite por área em relação aos demais, explicado pela maior produção de MS.(AU)

The objective of this work was to evaluate the potential of milk production ha-1 of three consortia of black oats and legumes in detriment to black oats fertilized with N mineral. The treatments used were black oats + 200kg of N ha-1 (Av+N); black oats + white clover (Av+Tb); black oats + vetch (Av+Er) and black oats + red clover (Av+Tv). The species were implanted in 80 m2 plots under a complete randomized complete block design with four replicates. Samples were collected three times and the material evaluated was dry matter yield, chemical and bromatological composition (CP, EE, NDF, ADF, NFC, MM, estimated dry matter digestibility and NDF digestibility in 48 hours) and estimated milk production by area (kg ha-1). The results were submitted to analysis of variance and the means were compared by Tukey test at 5% probability. The chemical-bromatological composition did not differ between Av+N and Av+Er treatments in any of the evaluated attributes. The Av+Er treatment provided higher milk yield per area in relation to the others, explained by the higher DM production.(AU)

Growth, gas exchanges and production of beet CV. katrina under organo-mineral fertilization / Crescimento, trocas gasosas e produção da beterraba CV. Katrina sob adubação organomineral

The beet culture has great economic and food importance in the world, especially with respect to energy generation. In Brazil the culture is still little studied, lacking studies in all stages of production of culture, mainly in the management of fertilization. This study aimed to evaluate the effect of organo-mineral fertilization on growth, gas exchanges and production of beet, cv. Katrina. The experiment was conducted under field conditions in the municipality of Pombal-PB, Brazil, from September to December 2015, in a randomized block design. The treatments were arranged in a 4 x 2 factorial scheme and corresponded to four periods of fermentation of the biofertilizer (10, 20, 30 and 40 days) applied in soils with and without mineral fertilization, with four replicates and 18 plants evaluated per plot. Plants were conducted for 70 days after transplanting, in 15-cm-high, 1-m-wide beds. During this period, plant growth, gas exchanges and production components were evaluated. The application of mineral biofertilizer fermented for 20 to 30 days, associated with mineral fertilization with 36 g m-2 of P2O5, 18.0 g m-2 of K2O and 14 g m-2 of N at planting, promoted better performance of growth, gas exchanges and production of beet plants. In the soil without mineral fertilization, it is recommended to use the longest biofertilizer fermentation periods, 30 to 40 days, for beet cultivation.

A cultura da beterraba tem grande importância econômica e alimentar no mundo, especialmente no que diz respeito à geração de energia. No Brasil, a cultura ainda é pouco estudada, faltando estudos em todos os estágios de produção da cultura, principalmente no manejo da adubação. Objetivou-se no presente trabalho, avaliar a adubação organomineral no crescimento, trocas gasosas e produção da beterraba cv. Katrina. O experimento foi conduzido em condições de campo, no município de Pombal, PB, no período de setembro a dezembro de 2015. O delineamento experimental utilizado foi o de blocos ao acaso, com tratamentos arranjados em esquema fatorial 4 x 2, relativos a quatro períodos de fermentação do biofertilizante (10, 20, 30 e 40 dias) aplicados em solos com e sem adubação mineral, com quatro repetições e 18 plantas úteis por parcela. As plantas foram conduzidas durante 70 dias após o transplantio, em canteiros de 15 cm de altura, com 1 m de largura. Durante esse período, avaliou-se o crescimento, trocas gasosas e os componentes de produção. A adubação com biofertilizante mineral fermentado no período entre 20 e 30 dias associado à adubação mineral com 36 g m-2 de P2O5, 18,0 g m-2 de K2O e 14 g m-2 de N no plantio, proporcionou melhor desempenho no crescimento, trocas gasosas e produção da beterraba. No solo sem adubação mineral, recomenda-se a utilização dos maiores períodos de fermentação do biofertilizante, 30 a 40 dias, para o cultivo da beterraba.

Early fruiting in Synsepalum dulcificum (Schumach. & Thonn.) Daniell juveniles induced by water and inorganic nutrient management.

Background. The miracle plant, Synsepalum dulcificum (Schumach. & Thonn.) Daniell is a native African orphan crop species that has recently received increased attention due to its promise as a sweetener and source of antioxidants in both the food and pharmaceutical industries. However, a major obstacle to the species' widespread utilization is its relatively slow growth rate and prolonged juvenile period. Method. In this study, we tested twelve treatments made up of various watering regimes and exogenous nutrient application (nitrogen, phosphorus and potassium, at varying dosages) on the relative survival, growth, and reproductive development of 15-months-old S. dulcificum juveniles. Results. While the plants survived under most tested growing conditions, nitrogen application at doses higher than 1.5 g [seedling] -1 was found to be highly detrimental, reducing survival to 0%. The treatment was found to affect all growth traits, and juveniles that received a combination of nitrogen, phosphorus, and potassium (each at a rate of 1.5 g [seedling] -1), in addition to daily watering, exhibited the most vegetative growth. The simple daily provision of adequate water was found to greatly accelerate the transition to reproductive maturity in the species (from >36 months to an average of 23 months), whereas nutrient application affected the length of the reproductive phase within a season, as well as the fruiting intensity. Conclusions. This study highlights the beneficial effect of water supply and fertilization on both vegetative and reproductive growth in S. dulcificum. Water supply appeared to be the most important factor unlocking flowering in the species, while the combination of nitrogen, phosphorus and potassium at the dose of 1.5 g (for all) consistently exhibited the highest performance for all growth and yield traits. These findings will help intensify S. dulcificum's breeding and horticultural development.

Nitrogen losses, uptake and abundance of ammonia oxidizers in soil under mineral and organo-mineral fertilization regimes.

BACKGROUND: A laboratory incubation experiment and greenhouse studies investigated the impact of organo-mineral (OM) fertilization as an alternative practice to conventional mineral (M) fertilization on nitrogen (N) uptake and losses in perennial ryegrass (Lolium perenne) as well as on soil microbial biomass and ammonia oxidizers. RESULTS: While no significant difference in plant productivity and ammonia emissions between treatments could be detected, an increase in soil total N content and an average 17.9% decrease in nitrates leached were observed in OM fertilization compared with M fertilization. The microbial community responded differentially to treatments, suggesting that the organic matter fraction of the OM fertilizer might have influenced N immobilization in the microbial biomass in the short-medium term. Furthermore, nitrate contents in fertilized soils were significantly related to bacterial but not archaeal amoA gene copies, whereas in non-fertilized soils a significant relationship between soil nitrates and archaeal but not bacterial amoA copies was found. CONCLUSION: The application of OM fertilizer to soil maintained sufficient productivity and in turn increased N use efficiency and noticeably reduced N losses. Furthermore, in this experiment, ammonia-oxidizing bacteria drove nitrification when an N source was added to the soil, whereas ammonia-oxidizing archaea were responsible for ammonia oxidation in non-fertilized soil. © 2015 Society of Chemical Industry.

Produção de biomassa de calendula officinalis l. adubada com fósforo e cama-de-frango / Biomass yield of Calendula officinalis L. fertilized with phosporus and chicken manure

Objetivou-se, neste trabalho, avaliar a influência do fósforo e da cama-de-frango semidecomposta na produção de capítulos florais da Calendula officinalis L. Os fatores em estudo foram cinco doses de fósforo (4,3; 25,8; 43,0; 60,2; 81,7 kg ha-1 de P2O5), na forma de superfosfato triplo e cinco doses de cama-de-frango semidecomposta (1.000; 6.000; 10.000; 14.000 e 19.000 kg ha-1). Para combinar o fósforo e a cama-de-frango, usou-se a matriz experimental Plan Puebla III resultando em nove tratamentos (25,8 e 6.000; 60,2 e 6.000; 25,8 e 14.000; 60,2 e 14.000; 43,0 e 10.000; 4,3 e 6.000; 81,7 e 14.000; 25,8 e 1.000; 60,2 e 19.000 kg ha-1 de P e cama-de-frango, respectivamente) no delineamento de blocos casualizados, com quatro repetições. A altura média final das plantas, aos 120 dias, ficou em torno de 60,0 cm, independente dos tratamentos. A produção máxima de capítulos florais da calêndula foi de 9.755,16 mil ha-1,obtida com o uso de 49,15 kg ha-1 de P2O5 associada a 13.401,10 kg ha-1 de cama-de-frango. A maior produção (11.058,89 kg ha-1)de massa fresca de capítulos florais de calêndula foi obtida com 49,98 kg ha-1 de P2O5 e 13.266,59 kg ha-1 de cama-de-frango. As produções máximas de massas secas de capítulos florais (2.227,61 kg ha-1) foram obtidas com 39,62 kg ha-1 de P2O5 e 8.109,75 kg ha-1 de cama-de-frango. Concluiu-se que para se obter maior produção de massa seca de capítulos florais, componente de maior importância comercial, a calêndula deve ser cultivada utilizando adubação com HH 40 kg ha-1 de P2O5 e H" 8.000 kg ha-1 de cama-de-frango.

The aim of this work was to evaluate the influence of phosphorus and semi-decomposed chicken manure on capitula yield of Calendula officinalis L. The studied factors were five doses of phosphorus (4.3, 25.8, 43.0, 60.2, and 81.7 kg ha-1 P2O5) in the triple super phosphate form and five doses of semi-decomposed chicken manure (1000, 6000, 10000, 14000, and 19000 kg ha-1). The Plan Puebla experimental matrix was used to combine phosphors and chicken manure, which resulted in nine treatments, viz. 25.8 + 6000, 60.2 + 6000, 25.8 + 14000, 60.2 + 14000, 43.0 + 10000, 4.3 + 6000, 81.7 + 14000, 25.8 + 1000, and 60.2 + 19000 (first figure representing kg ha-1P; second figure, kg ha-1chicken manure) in randomized block design with four replications. Final average heights of plants at 120 days were about 60.0 cm, independently of the treatments. Maximum yield of pot marigold capitula was 9755.16 x 10³ ha-1, which was obtained with the use of 49.15 kg ha-1 P2O5 associated to 13401.10 kg ha-1 chicken manure. The highest yield (11058.89 kg ha-1)of fresh biomass of pot marigold capitula was obtained with 49.98 kg ha-1 P2O5 and 13266.59 kg ha-1 chicken manure. Maximum yields of dried mass of capitula (2227.61 kg ha-1) were obtained with 39.62 kg ha-1 P2O5 and 8109.75 kg ha-1 chicken manure. It was concluded that to obtain the greatest dried mass yield of capitula, which constituent the most important commercial product of pot marigold, the plant must be cultivated using fertilization with H" 40 kg ha-1 P2O5 and H" 8000 kg ha-1 chicken manure.