DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2022
Purpose Nitrogen-fixing bacteria (NFB) are essential for biologically fixing nitrogen in natural ... more Purpose Nitrogen-fixing bacteria (NFB) are essential for biologically fixing nitrogen in natural and soybean crop systems. The use of organomineral fertilizers is a promising crop management tool made from the mixing of an organic source and mineral fertilizers. This study evaluated the efficacy of an organomineral fertilizer (sewage sludge-based) as a carrier for the Azospirillum brasilense inoculation and the influence of A. brasilense plus Bradyrhizobium japonicum on the soybean antioxidant metabolism. Method The experiment was performed under greenhouse conditions. The soybean cultivar (AS 3680 IPRO) was evaluated in a 4×2(+1) factorial scheme, corresponding to four doses of A. brasilense [0, 100, 200, 300 mL ha-1 (2x10 8 viable cells mL-1) per 50 kg-1 of soybean seeds], with or without B. japonicum [100 mL ha-1 (5x10 9 viable cells mL-1) per 50 kg-1 of soybean seeds], and a control treatment (without inoculants or fertilizers). Soybean antioxidant metabolism (enzymes, oxidative processes, proline amino acid) was evaluated in different plant stages. Results The seed inoculation with A. brasilense via organomineral fertilizer enhanced the soybean plant protection factors. Plant protection to stresses happened mainly by reductions in the superoxide dismutase activity, lipid peroxidation, and hydrogen peroxide concentration. The co-inoculation of A. brasilense with B. japonicum enhanced the proline activity at the V3 and R5 soybean phenological stage compared to A. brasilense inoculated alone. Conclusion The studied organomineral fertilizer is an efficient inoculant carrier for A. brasilense in soybean plants via seed treatment. The protective results observed for A. brasilense were improved when co-inoculated with B. japonicum.
DOAJ (DOAJ: Directory of Open Access Journals), Aug 1, 2017
Soil organic carbon and carbon stock influence, directly or indirectly, most of soil aggregate st... more Soil organic carbon and carbon stock influence, directly or indirectly, most of soil aggregate stability indicators. The objective of this study was to quantify the production of dry biomass (DB), total organic carbon (TOC) and carbon stock (CStk) in soil, and to evaluate their influence on some indicators of aggregation in an Oxisol at a Cerrado biome in Uberaba-MG, Brazil. The design was completely randomized blocks, in two evaluation periods: three and six cuts, at six depths (0-0.1, 0.1-0.2, 0.2-0.3, 0.3-0.4, 0.4-0.5 and 0.5-0.6 m). It was evaluated: soil density (SD), volumetric humidity (VH), aggregate stability index (AEI), weighted mean diameter (WDA), mean diameter (GDA), index of aggregates with diameter greater than 2 mm (AI) and sensitivity index (SI), replicated by 4. The best AEI of the soil and the highest TOC contents were found in the most superficial layers, 0 to 0.2 m, for both cuttings. The greater values of TOC and CStk, occurred at the sixth cut area, where there was a higher amount of DB on soil surface. The higher levels of organic matter did not provide higher AEI in the area of sixth cut, when compared to that of the third cut. The TOC and CStk levels in both areas generally had a positive influence on soil aggregation indicators for both cuts.
In no-tillage areas, cover crops are a continuous supply of organic matter and other positive imp... more In no-tillage areas, cover crops are a continuous supply of organic matter and other positive improvements to the soil’s structural quality. We evaluated soil physical attributes in area cultivated with brassica crops on residues of cover crops cultivated under no-tillage. Six cover crops coverages [1-Brachiaria (B), 2-Sunn hemp (S), 3-Pearl millet (M), 4-S + B; 5-B + M; 6-S + M] and a native area (Cerrado biome), were evaluated for soil resistance to penetration (RP), soil density (SD), soil macroporosity, microporosity, volumetric moisture (VM), weighted mean diameter, geometric mean diameter, and aggregate stability index. RP and VM differed among treatments; no compacted soil layer was observed at up to 0.4 m soil depth; Low RP and SD were observed for Brachiaria and Pearl millet (Poaceae) compared to Sunn hemp (Fabaceae) in deeper soil layers; The principal components and cluster analysis indicated B + M as the most promising coverage for deep soil structuring. The soil physica...
Soil pH correction and balanced fertilization are essential for coffee production and drink quali... more Soil pH correction and balanced fertilization are essential for coffee production and drink quality. The objective of this study was to evaluate strategies of soil limestone management to Arabica coffee plant development and yield. Five limestone management strategies were studied [T1: 100% limestone, relative power of total neutralization (RPTN) 100%, applied in September; T2: 50% in September + 50% in January (RPTN 100%); T3: 50% in September + 50% in January (RPTN 140%); T4: 100% (RPTN 100%) in September + 100% (RPTN 140%) in January; T5: 100% (RPTN 140%) in September + 100% (RPTN 100%) in January] in a 25-years-old commercial Arabica coffee area. Soil chemical attributes, plant nutritional status, biometrics, and yield were evaluated 120 days after treatment's application. Soil Ca and Mg levels and base saturation increased for T5 limestone management strategy. The improvements in soil fertility did not alter the coffee leaf contents of the macronutrients but increased the micronutrient levels after the second limestone application. Split limestone application and mixing limestone with different RPTNs (140 before 100%) improved soil Ca, Mg, base saturation, and coffee cherry production. The sole application of the recommended limestone dose (RPTN 100%) can reduce responses compared to more complex limestone managements.
DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2022
Purpose Nitrogen-fixing bacteria (NFB) are essential for biologically fixing nitrogen in natural ... more Purpose Nitrogen-fixing bacteria (NFB) are essential for biologically fixing nitrogen in natural and soybean crop systems. The use of organomineral fertilizers is a promising crop management tool made from the mixing of an organic source and mineral fertilizers. This study evaluated the efficacy of an organomineral fertilizer (sewage sludge-based) as a carrier for the Azospirillum brasilense inoculation and the influence of A. brasilense plus Bradyrhizobium japonicum on the soybean antioxidant metabolism. Method The experiment was performed under greenhouse conditions. The soybean cultivar (AS 3680 IPRO) was evaluated in a 4×2(+1) factorial scheme, corresponding to four doses of A. brasilense [0, 100, 200, 300 mL ha-1 (2x10 8 viable cells mL-1) per 50 kg-1 of soybean seeds], with or without B. japonicum [100 mL ha-1 (5x10 9 viable cells mL-1) per 50 kg-1 of soybean seeds], and a control treatment (without inoculants or fertilizers). Soybean antioxidant metabolism (enzymes, oxidative processes, proline amino acid) was evaluated in different plant stages. Results The seed inoculation with A. brasilense via organomineral fertilizer enhanced the soybean plant protection factors. Plant protection to stresses happened mainly by reductions in the superoxide dismutase activity, lipid peroxidation, and hydrogen peroxide concentration. The co-inoculation of A. brasilense with B. japonicum enhanced the proline activity at the V3 and R5 soybean phenological stage compared to A. brasilense inoculated alone. Conclusion The studied organomineral fertilizer is an efficient inoculant carrier for A. brasilense in soybean plants via seed treatment. The protective results observed for A. brasilense were improved when co-inoculated with B. japonicum.
DOAJ (DOAJ: Directory of Open Access Journals), Aug 1, 2017
Soil organic carbon and carbon stock influence, directly or indirectly, most of soil aggregate st... more Soil organic carbon and carbon stock influence, directly or indirectly, most of soil aggregate stability indicators. The objective of this study was to quantify the production of dry biomass (DB), total organic carbon (TOC) and carbon stock (CStk) in soil, and to evaluate their influence on some indicators of aggregation in an Oxisol at a Cerrado biome in Uberaba-MG, Brazil. The design was completely randomized blocks, in two evaluation periods: three and six cuts, at six depths (0-0.1, 0.1-0.2, 0.2-0.3, 0.3-0.4, 0.4-0.5 and 0.5-0.6 m). It was evaluated: soil density (SD), volumetric humidity (VH), aggregate stability index (AEI), weighted mean diameter (WDA), mean diameter (GDA), index of aggregates with diameter greater than 2 mm (AI) and sensitivity index (SI), replicated by 4. The best AEI of the soil and the highest TOC contents were found in the most superficial layers, 0 to 0.2 m, for both cuttings. The greater values of TOC and CStk, occurred at the sixth cut area, where there was a higher amount of DB on soil surface. The higher levels of organic matter did not provide higher AEI in the area of sixth cut, when compared to that of the third cut. The TOC and CStk levels in both areas generally had a positive influence on soil aggregation indicators for both cuts.
In no-tillage areas, cover crops are a continuous supply of organic matter and other positive imp... more In no-tillage areas, cover crops are a continuous supply of organic matter and other positive improvements to the soil’s structural quality. We evaluated soil physical attributes in area cultivated with brassica crops on residues of cover crops cultivated under no-tillage. Six cover crops coverages [1-Brachiaria (B), 2-Sunn hemp (S), 3-Pearl millet (M), 4-S + B; 5-B + M; 6-S + M] and a native area (Cerrado biome), were evaluated for soil resistance to penetration (RP), soil density (SD), soil macroporosity, microporosity, volumetric moisture (VM), weighted mean diameter, geometric mean diameter, and aggregate stability index. RP and VM differed among treatments; no compacted soil layer was observed at up to 0.4 m soil depth; Low RP and SD were observed for Brachiaria and Pearl millet (Poaceae) compared to Sunn hemp (Fabaceae) in deeper soil layers; The principal components and cluster analysis indicated B + M as the most promising coverage for deep soil structuring. The soil physica...
Soil pH correction and balanced fertilization are essential for coffee production and drink quali... more Soil pH correction and balanced fertilization are essential for coffee production and drink quality. The objective of this study was to evaluate strategies of soil limestone management to Arabica coffee plant development and yield. Five limestone management strategies were studied [T1: 100% limestone, relative power of total neutralization (RPTN) 100%, applied in September; T2: 50% in September + 50% in January (RPTN 100%); T3: 50% in September + 50% in January (RPTN 140%); T4: 100% (RPTN 100%) in September + 100% (RPTN 140%) in January; T5: 100% (RPTN 140%) in September + 100% (RPTN 100%) in January] in a 25-years-old commercial Arabica coffee area. Soil chemical attributes, plant nutritional status, biometrics, and yield were evaluated 120 days after treatment's application. Soil Ca and Mg levels and base saturation increased for T5 limestone management strategy. The improvements in soil fertility did not alter the coffee leaf contents of the macronutrients but increased the micronutrient levels after the second limestone application. Split limestone application and mixing limestone with different RPTNs (140 before 100%) improved soil Ca, Mg, base saturation, and coffee cherry production. The sole application of the recommended limestone dose (RPTN 100%) can reduce responses compared to more complex limestone managements.
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