cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.19944544.v1
title: CO2 emission affected by moisture content and aggregate sizes in a calcareous soil of Comarca Lagunera, Mexico

description: ABSTRACT Soil CO2 emissions are formed from biotic and abiotic processes related to organic carbon (SOC) and inorganic carbon (SIC), respectively. Calcareous soil has a high amount of SIC and occurs mainly in arid areas, and little is known about CO2 emissions from aggregates of this soil. This study aims to evaluate the emission of CO2 of aggregates from calcareous soil in the Comarca Lagunera, Mexico. Soil samples were taken from the layers of 0.00-0.15 and 0.15-0.30 m, and soil physical and chemical properties were determined. Aggregates distribution was obtained using the dry-sieving method. Macro (0.25–0.149 mm), meso (0.149–0.074 mm) and microaggregates (&lt;0.074 mm) were selected for incubation in a dynamic closed system for 30 days under two moisture contents (15 and 30 %, dry weight basis). The CO2 emissions were quantified using a non-dispersive infrared gas analyzer (IRGA). From total carbon measured, 97 % were found to be SIC. Soil texture is a sandy clay loam with a field capacity and a permanent wilting point of 27 and 17 %, respectively. From whole soil aggregates, 60 % were distributed in fractions lower than 0.25 mm diameter, which are highly erodible by the wind. Soil moisture content had a significant effect on the emission of CO2. The highest accumulated CO2 emission was registered in the superficial layer (0.00-0.15 m) within 0.25 mm aggregates (29.4 g m-2 h-1), which turned out higher than reported for similar areas. The CO2 emissions were attributed to the dissolution - reprecipitation process of high concentrations of SIC present in soil, involving a considerable contribution of CO2 to the atmosphere.
DOI: 10.6084/m9.figshare.19944536.v1
title: S15 - Whitlock and Wilson, 2020 - matrix with TATE-099 added

description: Whitlock and Wilson (2020) data matrix with TATE-099 added for phylogenetic analysis.
DOI: 10.6084/m9.figshare.19944549.v1
title: Adoption of the no-tillage system in Paraná State: A (re)view

description: ABSTRACT The concept of a no-tillage system (NTS), or “Sistema Plantio Direto,” was established in Brazil from the evolution of no-tillage (NT) or “Plantio Direto,” given the edaphoclimatic conditions and the need to promote chemical, physical and biological improvements in cultivated soils. While “Plantio Direto” is a conservationist practice, “Sistema Plantio Direto” presents itself as an agricultural production system based on the simultaneous adoption of minimum soil disturbance, maintenance of permanent soil cover and crop rotation. This study reviews the concepts of “Plantio Direto” and “Sistema Plantio Direto” in the Brazilian literature and uses two case studies in Paraná State to demonstrate the practical implications of these concepts. These two terms and their variations are recurrent themes in Brazilian scientific research and the professional environment, and may occur erroneously, hindering their adoption, results and implications. Regarding the “Sistema Plantio Direto,” we highlight the need to clarify the concepts of its basic practices to parameterize and characterize this process. The definition of crop rotation, for example, requires limits on the number of species along a given time scale, thus enabling their identification. Regarding the case studies, most grain crops conducted in Paraná State did not adopt the “Sistema Plantio Direto,” mainly neglecting the component of crop rotation. Nevertheless, the use of the “no-tillage system participatory quality index” (PQI) tool can contribute to the assessment and monitoring of the quality of the “Sistema Plantio Direto.” However, it requires adjustments to differentiate the “Sistema Plantio Direto” from the “Plantio Direto.”
DOI: 10.6084/m9.figshare.19944549
title: Adoption of the no-tillage system in Paraná State: A (re)view

description: ABSTRACT The concept of a no-tillage system (NTS), or “Sistema Plantio Direto,” was established in Brazil from the evolution of no-tillage (NT) or “Plantio Direto,” given the edaphoclimatic conditions and the need to promote chemical, physical and biological improvements in cultivated soils. While “Plantio Direto” is a conservationist practice, “Sistema Plantio Direto” presents itself as an agricultural production system based on the simultaneous adoption of minimum soil disturbance, maintenance of permanent soil cover and crop rotation. This study reviews the concepts of “Plantio Direto” and “Sistema Plantio Direto” in the Brazilian literature and uses two case studies in Paraná State to demonstrate the practical implications of these concepts. These two terms and their variations are recurrent themes in Brazilian scientific research and the professional environment, and may occur erroneously, hindering their adoption, results and implications. Regarding the “Sistema Plantio Direto,” we highlight the need to clarify the concepts of its basic practices to parameterize and characterize this process. The definition of crop rotation, for example, requires limits on the number of species along a given time scale, thus enabling their identification. Regarding the case studies, most grain crops conducted in Paraná State did not adopt the “Sistema Plantio Direto,” mainly neglecting the component of crop rotation. Nevertheless, the use of the “no-tillage system participatory quality index” (PQI) tool can contribute to the assessment and monitoring of the quality of the “Sistema Plantio Direto.” However, it requires adjustments to differentiate the “Sistema Plantio Direto” from the “Plantio Direto.”
DOI: 10.6084/m9.figshare.19944536
title: FIGURE S15 - Whitlock and Wilson, 2020 - matrix with TATE-099 added

description: Whitlock and Wilson (2020) data matrix with TATE-099 added for phylogenetic analysis.
DOI: 10.6084/m9.figshare.19944536.v3
title: FIGURE S15 - Whitlock and Wilson, 2020 - matrix with TATE-099 added

description: Whitlock and Wilson (2020) data matrix with TATE-099 added for phylogenetic analysis.
DOI: 10.6084/m9.figshare.19944536.v2
title: S15 - Whitlock and Wilson, 2020 - matrix with TATE-099 added

description: Whitlock and Wilson (2020) data matrix with TATE-099 added for phylogenetic analysis.
DOI: 10.6084/m9.figshare.19944553
title: Nitrogen use efficiency and grain yield of corn hybrids as affected by nitrogen rates and sowing dates in subtropical environment

description: ABSTRACT Delay of sowing date in subtropical environments with long growing seasons can modify the yield response of corn hybrids to nitrogen (N) fertilization. This study evaluated the effects of the sowing time, and N top-dress rate on corn hybrids’ yield and N-use efficiency with different cycles. Two field experiments were carried out in subtropical environment of southern Brazil. The following factors were investigated: corn hybrids (AG9025, super early cycle and P30F53, early cycle), sowing times (early and late spring), and N top-dress rates (0, 150, 300 and 450 kg ha-1). The delay of sowing date from early to late spring reduced 10 % the number of kernels per ear, decreasing grain yield. Corn presented lower yield potential in late sowings (-24 %), associated with a smaller response of grain yield to the N rate increase. The maximum corn yield was achieved at a rate of 360 kg ha-1 of N in early spring sowing and 300 kg ha-1 in late spring. The hybrid with early cycle presented greater yield stability and higher N use efficiency than the super early cycle hybrid in the late sowing. The N agronomic efficiency use is 47 % lower in late spring sowing than in early spring sowing. Regardless of the sowing date, the N use efficiency decreased 0.08 for each kg ha-1 N rate increase. This study suggests a reduction of at least 20 % in the N top-dress rate when the sowing date of corn is delayed to late spring in southern Brazil to decrease N losses and production costs.
DOI: 10.6084/m9.figshare.19944553.v1
title: Nitrogen use efficiency and grain yield of corn hybrids as affected by nitrogen rates and sowing dates in subtropical environment

description: ABSTRACT Delay of sowing date in subtropical environments with long growing seasons can modify the yield response of corn hybrids to nitrogen (N) fertilization. This study evaluated the effects of the sowing time, and N top-dress rate on corn hybrids’ yield and N-use efficiency with different cycles. Two field experiments were carried out in subtropical environment of southern Brazil. The following factors were investigated: corn hybrids (AG9025, super early cycle and P30F53, early cycle), sowing times (early and late spring), and N top-dress rates (0, 150, 300 and 450 kg ha-1). The delay of sowing date from early to late spring reduced 10 % the number of kernels per ear, decreasing grain yield. Corn presented lower yield potential in late sowings (-24 %), associated with a smaller response of grain yield to the N rate increase. The maximum corn yield was achieved at a rate of 360 kg ha-1 of N in early spring sowing and 300 kg ha-1 in late spring. The hybrid with early cycle presented greater yield stability and higher N use efficiency than the super early cycle hybrid in the late sowing. The N agronomic efficiency use is 47 % lower in late spring sowing than in early spring sowing. Regardless of the sowing date, the N use efficiency decreased 0.08 for each kg ha-1 N rate increase. This study suggests a reduction of at least 20 % in the N top-dress rate when the sowing date of corn is delayed to late spring in southern Brazil to decrease N losses and production costs.
DOI: 10.6084/m9.figshare.19944555
title: Nitrogen release from pelletized poultry fertilizer in two soils: influence of soil moisture and microbial biomass

description: ABSTRACT Nitrogen release from organic amendments, e.g., from organic agriculture, is a key process to raise soil fertility to sustain crop production in low environmental impact agroecosystems. This study aimed to investigate nitrogen release from a pelletized organic amendment containing poultry litter, guano and pot ale applied to soil from a field under two different management systems: an alfalfa-based crop rotation, enriched with N by the legume, under low-intensity tillage and a cereal-sunflower crop rotation under high-intensity tillage. Both sample types were evaluated under different temperature and soil moisture conditions (optimal and variable). The influence of the released amount of N-NO 3 on soil microbial biomass, soil basal respiration as well as on β-glucosidase, alkaline phosphatase and o-diphenoloxidase were investigated. The soil fertility level under low-intensity was higher than under high-intensity tillage. Consequently, compared to the control, microbial biomass growth in pellet-treated samples was intensified, both under optimal and variable conditions. Nevertheless, at the end of the experiment under variable conditions, microbial biomass decreased down to the level of the control. Soil moisture was identified as the limiting factor for basal respiration in low-tillage soil, while in the intensively tilled soil, low fertility was limiting, and respiration increased in response to pellet application, supplying C for microbial biomass. During the experimental period, the investigated enzyme activities were somewhat intensified by pellet application, contributing slightly to improve soil biochemical fertility. More N-NO 3 was released from soil under low than high-intensity tillage; however after 90-days, the pellet was not completely mineralized, and even at optimal soil moisture content, nitrate release was only partial. This indicated that pelletizing, though useful for practical reasons such as handling, storage and field distribution, can reduce the fertilization efficiency of organic amendments.
DOI: 10.6084/m9.figshare.19944555.v1
title: Nitrogen release from pelletized poultry fertilizer in two soils: influence of soil moisture and microbial biomass

description: ABSTRACT Nitrogen release from organic amendments, e.g., from organic agriculture, is a key process to raise soil fertility to sustain crop production in low environmental impact agroecosystems. This study aimed to investigate nitrogen release from a pelletized organic amendment containing poultry litter, guano and pot ale applied to soil from a field under two different management systems: an alfalfa-based crop rotation, enriched with N by the legume, under low-intensity tillage and a cereal-sunflower crop rotation under high-intensity tillage. Both sample types were evaluated under different temperature and soil moisture conditions (optimal and variable). The influence of the released amount of N-NO 3 on soil microbial biomass, soil basal respiration as well as on β-glucosidase, alkaline phosphatase and o-diphenoloxidase were investigated. The soil fertility level under low-intensity was higher than under high-intensity tillage. Consequently, compared to the control, microbial biomass growth in pellet-treated samples was intensified, both under optimal and variable conditions. Nevertheless, at the end of the experiment under variable conditions, microbial biomass decreased down to the level of the control. Soil moisture was identified as the limiting factor for basal respiration in low-tillage soil, while in the intensively tilled soil, low fertility was limiting, and respiration increased in response to pellet application, supplying C for microbial biomass. During the experimental period, the investigated enzyme activities were somewhat intensified by pellet application, contributing slightly to improve soil biochemical fertility. More N-NO 3 was released from soil under low than high-intensity tillage; however after 90-days, the pellet was not completely mineralized, and even at optimal soil moisture content, nitrate release was only partial. This indicated that pelletizing, though useful for practical reasons such as handling, storage and field distribution, can reduce the fertilization efficiency of organic amendments.
DOI: 10.6084/m9.figshare.19944556
title: Cover crops and controlled-release urea decrease nitrogen mobility and improve nitrogen stock in a tropical sandy soil with cotton cultivation

description: ABSTRACT Sandy soil often has low nitrogen (N) stock. Thus, crops grown in sandy soil rely on high levels of N fertilization. The use of cover crops and efficient fertilizers can increase N stock in the soil and N availability in the topsoil, and reduce overall fertilizer costs. The objective of this study was to evaluate the effects of cover crops (fallow, a single grass species (ruzigrass), two grass species (ruzigrass + millet), one grass species (millet) with legumes [lime-yellow pea (2018) and velvet bean (2019)], and a mixture of three cover crops [two grass species (ruzigrass + millet) and one legume (lime-yellow pea (2018)] and velvet bean (2019), N sources (conventional urea and controlled-release urea) and N doses (70, 100 and 130 kg ha-1) on N dynamics in an Oxisol (Latossolo) with sandy texture in Brazil cultivated with cotton. Systems with the cover crops (average) had 17 % more total N stock in the soil than fallow systems. Inorganic N increased only in systems with legumes. The systems with cover crop mixtures had 70 % more ammonium than fallow systems. Systems only with grass species had low percentages of inorganic N in relation to total N in the soil. The increase in N-fertilizer rates augmented the N stock in the soil (total and inorganic). In the first year, controlled-release urea reduced the availability of inorganic N in cotton flowering, except for the system with mixed cover crops. After the cotton harvest, areas of controlled-release urea application had 12 % more inorganic N than the areas with conventional urea. Our findings show that the combined use of cover crops with high biomass production, moderate dose of N and controlled-release N can increase the availability of inorganic nitrogen in the upper layers of the soil in tropical areas with sandy soil and this can reduce nitrogen fertilizer consumption in the medium and long term in cotton fields.
DOI: 10.6084/m9.figshare.19944556.v1
title: Cover crops and controlled-release urea decrease nitrogen mobility and improve nitrogen stock in a tropical sandy soil with cotton cultivation

description: ABSTRACT Sandy soil often has low nitrogen (N) stock. Thus, crops grown in sandy soil rely on high levels of N fertilization. The use of cover crops and efficient fertilizers can increase N stock in the soil and N availability in the topsoil, and reduce overall fertilizer costs. The objective of this study was to evaluate the effects of cover crops (fallow, a single grass species (ruzigrass), two grass species (ruzigrass + millet), one grass species (millet) with legumes [lime-yellow pea (2018) and velvet bean (2019)], and a mixture of three cover crops [two grass species (ruzigrass + millet) and one legume (lime-yellow pea (2018)] and velvet bean (2019), N sources (conventional urea and controlled-release urea) and N doses (70, 100 and 130 kg ha-1) on N dynamics in an Oxisol (Latossolo) with sandy texture in Brazil cultivated with cotton. Systems with the cover crops (average) had 17 % more total N stock in the soil than fallow systems. Inorganic N increased only in systems with legumes. The systems with cover crop mixtures had 70 % more ammonium than fallow systems. Systems only with grass species had low percentages of inorganic N in relation to total N in the soil. The increase in N-fertilizer rates augmented the N stock in the soil (total and inorganic). In the first year, controlled-release urea reduced the availability of inorganic N in cotton flowering, except for the system with mixed cover crops. After the cotton harvest, areas of controlled-release urea application had 12 % more inorganic N than the areas with conventional urea. Our findings show that the combined use of cover crops with high biomass production, moderate dose of N and controlled-release N can increase the availability of inorganic nitrogen in the upper layers of the soil in tropical areas with sandy soil and this can reduce nitrogen fertilizer consumption in the medium and long term in cotton fields.
DOI: 10.6084/m9.figshare.19944558
title: Rainfall erosivity estimation: Comparison and statistical assessment among methods using data from Southeastern Brazil

description: ABSTRACT Rainfall erosivity (R factor) is one of the six factors of the Universal Soil Loss Equation, being calculated based on the product of rainfall kinetic energy multiplied by its 30-minute maximum intensity. However, the lack of detailed and reliable rainfall data in many parts of the world has driven the use of other methods to estimate rainfall erosivity based on daily, monthly or annual data. These methods still need to be assessed to determine if their estimates are consistent with the standard method for calculating rainfall erosivity. This study aimed to select a consistent method for such replacement in Brazilian conditions without access the rainfall intensity data. The tested methods included: modified Fournier, MF; modified Fournier by Zhang, MF-Z; modified Fournier by Men, MF-M; Rainfall Disaggregation, RD; TRMM Satellite with modified Fournier coefficient, TRMM-F; and TRMM Satellite with monthly rainfall, TRMM-M. The rainfall data were obtained from the USP Meteorological Station, referring to the period from 2009 to 2015. The analyses were performed according to the Additive Main effects and Multiplicative Interaction (AMMI) model and Scott-Knott statistical tests. Considering the 1:1 line, all methods had a good adjustment, presenting similar behavior in relation to the standard method. The methods behaved differently for monthly and annual periods. The MF method proved to be capable of consistently replacing the standard method in all aforementioned situations. Considering the driest period, any method can be used. For annual rainfall erosivity estimation, the RD, MF, TRMM-F and TRMM-M methods can be applied; highlighting that the TRMM-based methods are optimal for locations without on-site rain gauges. Additionally, it was computed that the modified Fournier by Men and the modified Fournier by Zhang underestimated and overestimated the rainfall erosivity, respectively.
DOI: 10.6084/m9.figshare.19944558.v1
title: Rainfall erosivity estimation: Comparison and statistical assessment among methods using data from Southeastern Brazil

description: ABSTRACT Rainfall erosivity (R factor) is one of the six factors of the Universal Soil Loss Equation, being calculated based on the product of rainfall kinetic energy multiplied by its 30-minute maximum intensity. However, the lack of detailed and reliable rainfall data in many parts of the world has driven the use of other methods to estimate rainfall erosivity based on daily, monthly or annual data. These methods still need to be assessed to determine if their estimates are consistent with the standard method for calculating rainfall erosivity. This study aimed to select a consistent method for such replacement in Brazilian conditions without access the rainfall intensity data. The tested methods included: modified Fournier, MF; modified Fournier by Zhang, MF-Z; modified Fournier by Men, MF-M; Rainfall Disaggregation, RD; TRMM Satellite with modified Fournier coefficient, TRMM-F; and TRMM Satellite with monthly rainfall, TRMM-M. The rainfall data were obtained from the USP Meteorological Station, referring to the period from 2009 to 2015. The analyses were performed according to the Additive Main effects and Multiplicative Interaction (AMMI) model and Scott-Knott statistical tests. Considering the 1:1 line, all methods had a good adjustment, presenting similar behavior in relation to the standard method. The methods behaved differently for monthly and annual periods. The MF method proved to be capable of consistently replacing the standard method in all aforementioned situations. Considering the driest period, any method can be used. For annual rainfall erosivity estimation, the RD, MF, TRMM-F and TRMM-M methods can be applied; highlighting that the TRMM-based methods are optimal for locations without on-site rain gauges. Additionally, it was computed that the modified Fournier by Men and the modified Fournier by Zhang underestimated and overestimated the rainfall erosivity, respectively.
DOI: 10.6084/m9.figshare.19944559
title: Soil management practices adopted by farmers and how they perceive conservation agriculture

description: ABSTRACT In some rural properties of Brazil, soil and water conservation practices are partially or inappropriately implemented, intensifying soil erosion, even in no-tillage (NT) areas. This study aimed to check the farmer’s understanding of conservation agriculture (CA) and assess whether they are using practices appropriate to soil conservation. A basin in the state of Paraná, in Southern Brazil, was selected. Surveys were conducted based on a structured questionnaire and in-person interviews of 234 farmers. Among these farmers, 67 % do not understand CA pillars adequately, and 68 % stated they have been using NT for over 12 years. However, 58 % stated that they carried out some kind of soil preparation. Furthermore, some of the farmers only partially implemented CA, adopting a low level of crop diversification. The main problems pointed out by the farmers to justify simplifying the CA approach were soil compaction, low production of plant biomass and resistance of weeds to herbicides. Most farmers in the study do not have enough knowledge of the pillars of CA. As a result, there is little diversification in crop rotation, and the soil is continually disturbed with chiseling. Furthermore, although most farmers use terracing, they drive sprayers crossing terraces and following the slope, a practice that can impair the capacity of terraces to control surface water runoff. These practices do not contribute to soil and water conservation and endanger the sustainability of agricultural production systems.