cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6504260
title: Urochloa decumbens grown with different Eucalyptus clones in an integrated crop-livestock-forest system

description: ABSTRACT The objective of this study is to evaluate the forage mass, chemical composition, mineral content, and mineral absorption in signal grass (Urochloa decumbens) grown with different eucalypt clones in an integrated crop-livestock-forest (iCLF) system. The split-split-plot scheme included three replicates arranged in a completely randomized block design. The eucalyptus clones GG 100 and I 144 (Eucalyptus grandis × Eucalyptus urophylla) and VM 58 (Eucalyptus grandis × Eucalyptus camaldulensis) were distributed in the plots. The split plots corresponded to the growth ages of signal grass (10, 17, 24, 31, 38, 45, and 52 days after corn harvest for silage). The split-split plots corresponded to two sampling sites: center of the inter-row and soil under the Eucalyptus canopy. The Eucalyptus clones did not affect the forage mass of the grass. Forage mass was increased linearly as the grass matured and was more readily available in the center of the inter-row than under the tree canopy. The grass grown with clone I 144 presented better chemical composition, with higher levels of crude protein and phosphorus and lower levels of neutral detergent fiber. The Eucalyptus clones did not significantly affect mineral absorption. However, the Eucalyptus clones, grass age, and sampling sites significantly changed potassium absorption. It is concluded that the forage mass of signal grass is suitable for use in grazing at 38 to 52 days after corn harvest in the iCLF system in the autumn season in the Midwest region of Minas Gerais, without compromising the chemical composition of the grass.
DOI: 10.6084/m9.figshare.6504260.v1
title: Urochloa decumbens grown with different Eucalyptus clones in an integrated crop-livestock-forest system

description: ABSTRACT The objective of this study is to evaluate the forage mass, chemical composition, mineral content, and mineral absorption in signal grass (Urochloa decumbens) grown with different eucalypt clones in an integrated crop-livestock-forest (iCLF) system. The split-split-plot scheme included three replicates arranged in a completely randomized block design. The eucalyptus clones GG 100 and I 144 (Eucalyptus grandis × Eucalyptus urophylla) and VM 58 (Eucalyptus grandis × Eucalyptus camaldulensis) were distributed in the plots. The split plots corresponded to the growth ages of signal grass (10, 17, 24, 31, 38, 45, and 52 days after corn harvest for silage). The split-split plots corresponded to two sampling sites: center of the inter-row and soil under the Eucalyptus canopy. The Eucalyptus clones did not affect the forage mass of the grass. Forage mass was increased linearly as the grass matured and was more readily available in the center of the inter-row than under the tree canopy. The grass grown with clone I 144 presented better chemical composition, with higher levels of crude protein and phosphorus and lower levels of neutral detergent fiber. The Eucalyptus clones did not significantly affect mineral absorption. However, the Eucalyptus clones, grass age, and sampling sites significantly changed potassium absorption. It is concluded that the forage mass of signal grass is suitable for use in grazing at 38 to 52 days after corn harvest in the iCLF system in the autumn season in the Midwest region of Minas Gerais, without compromising the chemical composition of the grass.
DOI: 10.6084/m9.figshare.6504347
title: Growth and bromatological characteristics of Brachiaria decumbens and Brachiaria ruziziensis under shading and nitrogen

description: ABSTRACT This study aimed to evaluate the productive and qualitative characteristics of Brachiaria decumbens and Brachiaria ruziziensis subjected to three levels of artificial shading (0, 36 and 54%) and four nitrogen (N) doses (0; 50; 100 and 150 mg dm-3 soil), using completely randomized design with a factorial scheme 2 x 3 x 4, with three replications. The dry matter production (DMP), the number of tillers per pot, root weight and crude protein (CP) and neutral detergent fiber (NDF) contents were evaluated. Both grasses responded quadractly to N, but B. ruziziensis presented greater production under the two highest N doses. The tillers density increased with N dose and was reduced under shading. The root weight increased with N dose, linearly in the full sun and quadractly in the shade. The shading and N showed a positive influence on CP contents. For NDF content, was observed reduction with increase of N dose. The NDF content of B. decumbens increased with shading levels; for B. ruziziensis, the greatest value was observed under intermediate shading level. The N fertilization is an important strategy to improve DMP, tillers density and CP content, for both grasses. However, intense shading should be avoided, as it reduces tillering and root weight, which may threat pasture persistence.
DOI: 10.6084/m9.figshare.6504347.v1
title: Growth and bromatological characteristics of Brachiaria decumbens and Brachiaria ruziziensis under shading and nitrogen

description: ABSTRACT This study aimed to evaluate the productive and qualitative characteristics of Brachiaria decumbens and Brachiaria ruziziensis subjected to three levels of artificial shading (0, 36 and 54%) and four nitrogen (N) doses (0; 50; 100 and 150 mg dm-3 soil), using completely randomized design with a factorial scheme 2 x 3 x 4, with three replications. The dry matter production (DMP), the number of tillers per pot, root weight and crude protein (CP) and neutral detergent fiber (NDF) contents were evaluated. Both grasses responded quadractly to N, but B. ruziziensis presented greater production under the two highest N doses. The tillers density increased with N dose and was reduced under shading. The root weight increased with N dose, linearly in the full sun and quadractly in the shade. The shading and N showed a positive influence on CP contents. For NDF content, was observed reduction with increase of N dose. The NDF content of B. decumbens increased with shading levels; for B. ruziziensis, the greatest value was observed under intermediate shading level. The N fertilization is an important strategy to improve DMP, tillers density and CP content, for both grasses. However, intense shading should be avoided, as it reduces tillering and root weight, which may threat pasture persistence.
DOI: 10.6084/m9.figshare.7187318
title: Contribution of non-exchangeable K in soils from Southern Brazil under potassium fertilization and successive cropping

description: ABSTRACT Intense cropping of plants in pots was used to assess the contribution of non-exchangeable K to plant uptake in different soils of Paraná State, Brazil. Surface samples from nine soil types were fertilized or not with K fertilizer and subjected to six successive cropping (i.e., soybean, pearl millet, wheat, common beans, soybean and maize) under greenhouse conditions. The crops were grown in 8-L pots for 45 days, and at the end of the sixth cropping, the soil was sampled to determination non-exchangeable and exchangeable K. Shoot dry matter yield, K taken up, non-exchangeable pool contribution to K nutrition of plants were also determined. Soils differ in the ability to K supply to the plants in the short to medium term, due to the wide range of parent material and exchangeable K and non-exchangeable K pools. When the soils were not fertilized with K, the successive cropping of plants resulted in a continuous process of depletion of non-exchangeable K and exchangeable K pools; however, this depletion was less pronounced in soils with higher potential buffer capacity of K. Concentrations of non-exchangeable K and exchangeable K were increased with the addition of K fertilizers, indicating the occurrence of K fixation in soil. Non-exchangeable K contribution to K nutrition of plants during the six croppings ranged from 50 to 73% and from 1 to 18%, respectively, without and with K fertilizer addition. These data report the importance of non-exchangeable K pools in the supply of this nutrient to plants in agricultural production systems.
DOI: 10.6084/m9.figshare.7185281.v1
title: Production of organic compost from different plant waste generated in the management of a green urban space

description: ABSTRACT Plant waste generated in a properly treated arboretum promotes nutrient cycling, reducing the volume of the residue. The aim of this study was to evaluate the potential of plant waste generated in the management of the Botanical Gardens of Rio de Janeiro, Brazil, for the production of organic composts. An experiment was carried out over 110 days to compost leaves, shredded twigs and leaves, shredded twigs and leaves plus manure, blades of grass, and aquatic plants, to determine influence factors and the levels of N, P and K. The experimental design was completely randomised with five treatments and four replications. The manure had an influence on the decomposition of the shredded plant waste. The shredded waste plus manure, blades of grass and aquatic plants resulted in composts that were more stable as regards temperature, while the shredded waste and leaves required more time for the biomass to decompose. The grass and aquatic-plant material displayed higher levels of N and greater reductions in volume. The P and K content was maintained where losses occurred from leaching, due to the process being carried out in an open system.
DOI: 10.6084/m9.figshare.7185281
title: Production of organic compost from different plant waste generated in the management of a green urban space

description: ABSTRACT Plant waste generated in a properly treated arboretum promotes nutrient cycling, reducing the volume of the residue. The aim of this study was to evaluate the potential of plant waste generated in the management of the Botanical Gardens of Rio de Janeiro, Brazil, for the production of organic composts. An experiment was carried out over 110 days to compost leaves, shredded twigs and leaves, shredded twigs and leaves plus manure, blades of grass, and aquatic plants, to determine influence factors and the levels of N, P and K. The experimental design was completely randomised with five treatments and four replications. The manure had an influence on the decomposition of the shredded plant waste. The shredded waste plus manure, blades of grass and aquatic plants resulted in composts that were more stable as regards temperature, while the shredded waste and leaves required more time for the biomass to decompose. The grass and aquatic-plant material displayed higher levels of N and greater reductions in volume. The P and K content was maintained where losses occurred from leaching, due to the process being carried out in an open system.
DOI: 10.6084/m9.figshare.7185560
title: Crambe fruit drying with natural air in stationary dryers

description: ABSTRACT The aim of this study was to assess the drying behavior and quality of crambe fruit seeds dried with natural air and submitted to different airflows in stationary dryers. Dryings were carried out in July and September 2014. The experiment consisted of three treatments of drying the crambe fruits with natural air in stationary dryers with airflows of 10.08, 15.05, and 25.03 m3 min−1 t−1 and a control treatment composed of crambe fruits with an initial moisture content without going through the drying process. After drying, tests of moisture content, germination, germination rate index, and electrical conductivity were performed in order to compare the treatments. The data were submitted to analysis of variance and mean comparison by the Tukey's test at 5% significance. Among the airflows used in the experiment in both natural air dryings in July and September, no interference was observed for crambe fruit quality. Drying carried out in September was faster and showed a lower expenditure and cost of electricity when compared to that performed in July, which is due to better climatic conditions. No difference was observed in the drying times between airflows, but the drying with natural air using an airflow of 15.05 m3 min−1 t−1 was more profitable.
DOI: 10.6084/m9.figshare.7185560.v1
title: Crambe fruit drying with natural air in stationary dryers

description: ABSTRACT The aim of this study was to assess the drying behavior and quality of crambe fruit seeds dried with natural air and submitted to different airflows in stationary dryers. Dryings were carried out in July and September 2014. The experiment consisted of three treatments of drying the crambe fruits with natural air in stationary dryers with airflows of 10.08, 15.05, and 25.03 m3 min−1 t−1 and a control treatment composed of crambe fruits with an initial moisture content without going through the drying process. After drying, tests of moisture content, germination, germination rate index, and electrical conductivity were performed in order to compare the treatments. The data were submitted to analysis of variance and mean comparison by the Tukey's test at 5% significance. Among the airflows used in the experiment in both natural air dryings in July and September, no interference was observed for crambe fruit quality. Drying carried out in September was faster and showed a lower expenditure and cost of electricity when compared to that performed in July, which is due to better climatic conditions. No difference was observed in the drying times between airflows, but the drying with natural air using an airflow of 15.05 m3 min−1 t−1 was more profitable.
DOI: 10.25606/surf.c1b8ea8484fa0d00
title: The LOFAR Two-metre Sky Survey (LoTSS) V. Second data release (P169+55)

description: In this data release from the ongoing LOw-Frequency ARray (LOFAR) Two-metre Sky Survey (LoTSS) we present 120-168 MHz images covering 27% of the northern sky. Our coverage is split into two regions centred at approximately 12h45m +44◦30′ and 1h00m +28◦ 00′ and spanning 4178 and 1457 square degrees respectively. The images were derived from 3,451 hrs (7.6 PB) of LOFAR High Band Antenna data which were corrected for the direction-independent instrumental properties as well as direction-dependent ionospheric distortions during extensive, but fully automated, data processing. A catalogue of 4,396,228 radio sources is derived from our total intensity (Stokes I) maps, where the majority of these have never been detected at radio wavelengths before. At 6′′ resolution, our full bandwidth Stokes I continuum maps with a central frequency of 144 MHz have: a median rms sensitivity of 83 μ Jy/beam; a flux density scale accuracy of approximately 10%; an astrometric accuracy of 0.2′′; and we estimate the point-source completeness to be 90% at a peak brightness of 0.8 mJy/beam. By creating three 16 MHz bandwidth images across the band we are able to measure the in-band spectral index of many sources, albeit with an error on the derived spectral index of &gt; ±0.2 which is a consequence of our flux-density scale accuracy and small fractional bandwidth. Our circular polarisation (Stokes V) 20′′ resolution 120-168 MHz continuum images have a median rms sensitivity of 95 μ Jy/beam, and we estimate a Stokes I to Stokes V leakage of 0.056%. Our linear polarisation (Stokes Q and Stokes U) image cubes consist of 480 97.6 kHz wide planes and have a median rms sensitivity per plane of 10.8mJy/beam at 4′ and 2.2mJy/beam at 20′′; we estimate the Stokes I to Stokes Q/U leakage to be approximately 0.2%. Here we characterise and publicly release our Stokes I, Q, U and V images in addition to the calibrated uv-data to facilitate the thorough scientific exploitation of this unique dataset. This is field P169+55.
DOI: 10.6084/m9.figshare.20011342
title: Use of Spirulina platensis in treatment of fish farming wastewater

description: ABSTRACT Each year, the amount of fish produced around the world increases, which contributes to several environmental impacts such as the disposal of effluents without treatment in the environment. This scientific work had as main objective the development of Spirulina platensis in fish effluents, a low cost medium for the production of biomass, in order to reduce the levels of some inorganic nutrients to reach the allowed parameters by the Brazilian environmental standards for effluent disposal and to enable reuse of the water. Nile tilapia (Oreochromis niloticus) fingerlings were produced in fresh water. The effluent generated by the culture was transferred to a pool where seawater was added until the salinity of 10 ‰ was reached. A strain of cyanobacteria, Spirulina platensis, was inserted into the mixture in order to remove the nutrients dissolved on the fish culture effluent. The abiotic parameters analyzed were: absorbance, pH, dissolved oxygen, temperature, salinity and concentrations of ammonia, nitrite, nitrate and phosphate. The results revealed that the maximum cellular density of S. platensis resulted in the production of 0.22 g L-1 of dry biomass and maximum productivity of 0.03 g L-1 day-1. The concentration of ammonia, nitrite, nitrate and phosphate got lowered by more than 94.8%, maintaining the nutrient levels within the standards those required by Brazilian environmental standards. Hence, this effluent has become adequate for reuse in fish production or could be safely disposed in nature.
DOI: 10.6084/m9.figshare.20011342.v1
title: Use of Spirulina platensis in treatment of fish farming wastewater

description: ABSTRACT Each year, the amount of fish produced around the world increases, which contributes to several environmental impacts such as the disposal of effluents without treatment in the environment. This scientific work had as main objective the development of Spirulina platensis in fish effluents, a low cost medium for the production of biomass, in order to reduce the levels of some inorganic nutrients to reach the allowed parameters by the Brazilian environmental standards for effluent disposal and to enable reuse of the water. Nile tilapia (Oreochromis niloticus) fingerlings were produced in fresh water. The effluent generated by the culture was transferred to a pool where seawater was added until the salinity of 10 ‰ was reached. A strain of cyanobacteria, Spirulina platensis, was inserted into the mixture in order to remove the nutrients dissolved on the fish culture effluent. The abiotic parameters analyzed were: absorbance, pH, dissolved oxygen, temperature, salinity and concentrations of ammonia, nitrite, nitrate and phosphate. The results revealed that the maximum cellular density of S. platensis resulted in the production of 0.22 g L-1 of dry biomass and maximum productivity of 0.03 g L-1 day-1. The concentration of ammonia, nitrite, nitrate and phosphate got lowered by more than 94.8%, maintaining the nutrient levels within the standards those required by Brazilian environmental standards. Hence, this effluent has become adequate for reuse in fish production or could be safely disposed in nature.
DOI: 10.6084/m9.figshare.7186580
title: Growth and volatiles in the micropropagation of Santa Maria herb

description: ABSTRACT The aims of this study were to establish micropropagation for Chenopodium ambrosioides L. and analysis of volatile constituents in vitro as a function of different salt concentrations of MS medium and sucrose. The apical buds were established on MS medium added with 3% sucrose. The vegetative growth of nodal segments was tested in different salt concentrations of MS basic medium (0.25, 0.50, 1.00, 1.50, and 2.00) and of sucrose (5, 10, 20, 30, and 40 g L-1). Nodal and apical segments were tested in vertical and horizontal orientations. Different volumes of culture medium (20; 35, 50, 65, and 80 mL) were examined in the growth of nodal segments. Plants were acclimatized in three different substrates. The apical segments collected from matrices plants were successful when established in MS medium. A multiplication rate of 8.5 was obtained with nodal and apical segments without using growth regulator. MS medium with its salt concentration reduced by half (0.50 MS) and sucrose at the concentration of 30 g L-1 provided better in vitro growth of nodal segments. Four major volatile compounds (α-terpinene, p-cymene, Z-ascaridole, and E-ascaridole) varied at different salt concentrations and only α-terpinene showed difference for sucrose concentrations. Apical segments in vertical orientation and nodal segments in horizontal with 50 mL of culture medium showed better responses for the in vitro cultivation of C. ambrosioides L.
DOI: 10.6084/m9.figshare.7186580.v1
title: Growth and volatiles in the micropropagation of Santa Maria herb

description: ABSTRACT The aims of this study were to establish micropropagation for Chenopodium ambrosioides L. and analysis of volatile constituents in vitro as a function of different salt concentrations of MS medium and sucrose. The apical buds were established on MS medium added with 3% sucrose. The vegetative growth of nodal segments was tested in different salt concentrations of MS basic medium (0.25, 0.50, 1.00, 1.50, and 2.00) and of sucrose (5, 10, 20, 30, and 40 g L-1). Nodal and apical segments were tested in vertical and horizontal orientations. Different volumes of culture medium (20; 35, 50, 65, and 80 mL) were examined in the growth of nodal segments. Plants were acclimatized in three different substrates. The apical segments collected from matrices plants were successful when established in MS medium. A multiplication rate of 8.5 was obtained with nodal and apical segments without using growth regulator. MS medium with its salt concentration reduced by half (0.50 MS) and sucrose at the concentration of 30 g L-1 provided better in vitro growth of nodal segments. Four major volatile compounds (α-terpinene, p-cymene, Z-ascaridole, and E-ascaridole) varied at different salt concentrations and only α-terpinene showed difference for sucrose concentrations. Apical segments in vertical orientation and nodal segments in horizontal with 50 mL of culture medium showed better responses for the in vitro cultivation of C. ambrosioides L.
DOI: 10.6084/m9.figshare.7185902
title: Organic residue with high potassium content on sunflower cultivars

description: ABSTRACT The use of organic sources that include levels of potassium, in addition to having an influence on the achenes and on plant development, reduces production costs and has less impact on the environment. The aim of this study was to evaluate the efficiency of fertilisation using organic residue generated by the coffee roasting process, which has a high level of potassium, on agronomic characteristics, production components and physiological quality of the achenes. The experimental design was a 2x4+2 factorial scheme, with two cultivars, four doses of organic residue (T1=0, T2=40, T3=80 and T4=120 kg K ha-1), plus a control of potassium chloride at a dose of 60 kg K ha-1 for each cultivar. The variables under analysis were plant height, stem diameter at ground level, capitulum diameter, number of leaves, leaf area, leaf area index, 1000-achene weight, productivity and oil content. The physiological quality of the achenes was also determined by the germination test, first germination count, seedling emergence, emergence speed index, shoot length, shoot dry weight and accelerated-ageing test. Fertilisation with organic residue is efficient for the agronomic characteristics and production components of the sunflower; doses of less than 40 kg K ha-1 or over 70 kg K ha-1 from the organic residue may have a negative effect on the physiological quality of sunflower achenes.