Agronomic efficiency and genome mining analysis of the wheat-biostimulant rhizospheric bacterium Pseudomonas pergaminensis sp. nov. strain 1008T.

Pseudomonas sp. strain 1008 was isolated from the rhizosphere of field grown wheat plants at the tillering stage in an agricultural plot near Pergamino city, Argentina. Based on its in vitro phosphate solubilizing capacity and the production of IAA, strain 1008 was formulated as an inoculant for bacterization of wheat seeds and subjected to multiple field assays within the period 2010-2017. Pseudomonas sp. strain 1008 showed a robust positive impact on the grain yield (+8% on average) across a number of campaigns, soil properties, seed genotypes, and with no significant influence of the simultaneous seed treatment with a fungicide, strongly supporting the use of this biostimulant bacterium as an agricultural input for promoting the yield of wheat. Full genome sequencing revealed that strain 1008 has the capacity to access a number of sources of inorganic and organic phosphorus, to compete for iron scavenging, to produce auxin, 2,3-butanediol and acetoin, and to metabolize GABA. Additionally, the genome of strain 1008 harbors several loci related to rhizosphere competitiveness, but it is devoid of biosynthetic gene clusters for production of typical secondary metabolites of biocontrol representatives of the Pseudomonas genus. Finally, the phylogenomic, phenotypic, and chemotaxonomic comparative analysis of strain 1008 with related taxa strongly suggests that this wheat rhizospheric biostimulant isolate is a representative of a novel species within the genus Pseudomonas, for which the name Pseudomonas pergaminensis sp. nov. (type strain 1008T = DSM 113453T = ATCC TSD-287T) is proposed.

Interfaces between biodegradable organic matrices coating and MAP fertilizer for improve use efficiency.

Improving phosphorus (P) use efficiency is a challenge to promote a circular economy and greening the phosphorus cycle towards planetary sustainability. The disruptive innovation for phosphate fertilizers may help to reduce some unwelcome reactions that occur to P in soils. Monoammonium phosphate (MAP) coating with biodegradable organic polymers and the addition of magnesium (Mg) - a nutrient with a synergistic effect on the uptake of P, zinc (Zn), and boron (B) - emerge as a smart strategy to applying these micronutrients uniformly in soils. The objectives of this study were: to characterize the coated-MAP with biodegradable organic polymers, quantify the diffusion and availability of P in the soil, and evaluate the corn crop nutrition and yield during two crop seasons. The treatments were: MAP, MAP coated with biodegradable organic polymer (BOP), MAP + BOP + 1.3% of Zn + 0.33% of B, and MAP + BOP + 1.76% of Mg. The laboratory tests showed that the diffusion of MAP-based fertilizers was: MOMg (7.86 mm) = MO (8.82 mm) = MAP (8.84 mm) = MOM (8.51 mm) after 432 h. Coatings did not cause delays in the P-release in water at 25 °C since more than 95% of P was released within 24 h. In the field trials, the application of Mg, Zn, and B in the MAP coating did not increase nutrient leaf concentration. In the summer crop season, grain yield increased up to the P-rates of 85 kg of P2O5 ha-1, reaching the value of 6731 kg ha-1. Physical and chemical characteristics of MAP-fertilizers tend to improve with the coatings. The addition of biodegradable organic polymers, Mg, B, and Zn, as MAP-coatings did not enhance P diffusion, release, and availability in the soil and the crop nutrition. Coated-MAP improved corn yield only in the 2nd crop season.

Maize-Brachiaria intercropping: A strategy to supply recycled N to maize and reduce soil N2O emissions?

Nitrogen use in agriculture directly impacts food security, global warming, and environmental degradation. Forage grasses intercropped with maize produce feed for animals and or mulch for no-till systems. Forage grasses may exude nitrification inhibitors. It was hypothesized that brachiaria intercropping increases N recycling and maize grain yield and reduces nitrous oxide (N2O) emissions from soil under maize cropping. A field experiment was set up in December 2016 to test three cropping system (maize monocropped, maize intercropped with Brachiaria brizantha or with B. humidicola) and two N rates (0 or 150 kg ha-1). The grasses were sown with maize, but B. humidicola did not germinate well in the first year. B. brizantha developed slowly during the maize cycle because of shading but expanded after maize was harvested. The experiment was repeated in 2017/2018 when B. humidicola was replanted. N2O and carbon dioxide (CO2) emissions, maize grain yield and N content were measured during the two seasons. After the first maize harvest, the above- and below-ground biomass, C and N content of B. brizantha grown during fall-winter, and the biological nitrification inhibition potential of B. brizantha were evaluated. Maize yield responded to N fertilization (5.1 vs. 9.8 t ha-1) but not to brachiaria intercropping. B. brizantha recycled approximately 140 kg N ha-1 and left 12 t dry matter ha-1 for the second maize crop. However, the 2017/18 maize yields were not affected by the N recycled by B. brizantha, whereas N2O emissions were higher in the plots with brachiaria, suggesting that part of the recycled N was released too early after desiccation. Brachiarias showed no evidence of causing nitrification inhibition. The strategy of intercropping brachiarias did not increase maize yield, although it added C and recycled N in the system.

Efficiency of nitrogen use by sesame genotypes under brazilian semi-arid conditions

Nitrogen (N) is an essential macronutrient for plant growth and rate applications can influence the performance of sesame, and when applied in excess can cause nitrogen loss in the environment, and consequently make the cost of production more costly to the producer. Therefore, the objective of this work was to evaluate the efficiency of nitrogen use by different cultivars of irrigated sesame seeds under the edaphoclimatic conditions of the northeastern semi-arid region in two harvests. The experiments were carried out from February to May (1st harvest) and from July to October (2nd harvest) in 2016. The treatments were arranged in a split plot scheme, in which the plots were the five nitrogen doses (0, 30, 60, 90 and 120 kg ha-1), and in the subplots, the four sesame genotypes (CNPA G2, CNPA G3, CNPA G4 and BRS Seda), the design was in randomized complete blocks with four replications. The nitrogen use efficiency assessments evaluated were: agronomic efficiency (AE), physiological efficiency (PE), agrophysiological efficiency (APE), recovery efficiency (RE) and efficiency of use (EU). The rate that provided the greatest efficiency of use was 30 kg ha-1 of N applied. The cultivar BRS Seda had greater efficiency of use in relation to the other cultivars studied. The crop that had better efficiency of use was the 2nd agricultural harvest.

Efficiency in the use of phosphorus by cowpea genotypes / Eficiência do uso de fósforo por genótipos de caupi

Cowpea (Vigna unguiculata (L.) Walp.) is an edible legume with good ability to fix nitrogen and not demanding soil fertility. However, some genotypes may have a greater ability to utilize the nutrients available in the soil for their growth. Thus, the objective of this work was to evaluate the efficiency of phosphorus (P) use in genotypes of cowpea. The experiment was conducted in the field and the experimental design was a randomized complete block design with four replicates arranged in a 2 x 5 factorial scheme. The treatments consisted of two P doses (0 and 60 kg ha-1 of P2O5) and five bean genotypes (Paulistinha, BRS Xiquexique, Pingo de Ouro, Corujinha, and Costela de Vaca). Each plot was formed by four plant rows, measuring 3.0 m in length, spaced 1.0 x 0.3 m, and with two plants per hole. The genotypes responded significantly to the increase in P levels in the soil, with increases in the number of seeds per pod, number of pods per plant, productivity, dry mass, and plant P accumulation. "BRS Xiquexique" was efficient and responsive, and it could be indicated as the most appropriate for cultivation in the region. "Corujinha" is the most suitable cultivar for production in high levels of P among the creole genotypes evaluated. "Costela de Vaca" and "Paulistinha" can be indicated for low P production in the soil.

O feijão-caupi (Vigna unguiculata (L.) Walp.) é uma leguminosa comestível com boa capacidade de fixar nitrogênio e pouco exigente em fertilidade do solo. No entanto, alguns genótipos podem apresentar uma maior capacidade em utilizar os nutrientes disponíveis no solo para seu crescimento. Assim, o objetivo deste trabalho foi avaliar a eficiência do uso de fósforo em genótipos de feijão-caupi. O experimento Non-efficient and non-responsive Efficient and non-responsive Pingo de Ouro BRS Xiquexique PaulistinhaCostela de Vaca Efficient and responsiveCorujinha Non-efficient and responsive foi conduzido em campo, e o solo classificado como Argissolo Vermelho-Amarelo. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, disposto em um esquema fatorial 2 x 5. Os tratamentos foram constituídos pela combinação de duas doses de fósforo (0 e 60 kg ha-1 de P2O5) e cinco genótipos de feijão-caupi (Paulistinha, BRS Xiquexique, Pingo de Ouro, Corujinha e Costela de Vaca). Cada parcela foi formada por quatro fileiras de planta, medindo 3,0 m de comprimento, espaçadas de 1,0 x 0,3 m, com duas plantas por cova. Os genótipos responderam de forma significativa ao aumento do nível de fósforo no solo, com incrementos no número de sementes por vagem, número de vagens por planta, produtividade, massa seca e acúmulo de P da planta. O BRS Xiquexique foi eficiente e responsivo, podendo ser indicado como o mais apropriado para o cultivo na região. Corujinha é a cultivar mais indicada para produção em níveis alto de fósforo entre os genótipos crioulos avaliados. Os genótipos crioulos costela de Vaca e Paulistinha podem ser indicados para produção em baixo nível de fósforo.

Agronomic performance of carrot fertilized with roostertree [Calotropis procera (Ait.) R. BR.] in two growing seasons / Desempenho agronômico da cenoura adubada com flor-de-seda [Calotropis procera (Ait.) R. BR.] em duas épocas de cultivo

Because vegetables have a fast production cycle, they require fertilization in quantities and at ideal times to obtain maximum productivity, and green manure is an alternative practice to the use of mineral fertilizers. This study was conducted to evaluate the effects of different amounts of roostertree [Calotropis procera (Ait.) R. Br.] biomass and its incorporation times in two growing seasons, in the agronomic performance of carrots. The experiment was conducted on an experimental farm at the Universidade Federal Rural de Pernambuco (UFRPE) in the autumn-winter period (March-July 2012) and the spring-summer period (September-December 2012). The experimental design was a randomized block design with three replications. The treatments were arranged in a factorial 4 x 4 design; the first factor consists of four amounts of roostertree biomass (5.4, 8.8, 12.2 and 15.6 t ha-1 on a dry basis), and the second factor consists of four times of incorporation of this manure into the soil (0, 10, 20 and 30 days before sowing the carrots). The carrot cultivar used was Brasília. The following traits were evaluated: plant height, number of leaves per plant, root dry mass, total and commercial yield of roots. The best agronomic performance of carrot cultivar Brasília was found with the amount of roostertree biomass of 15.6 t ha-1, in the time of incorporation into the soil of 10 days before seeding. The cultivation in the autumn-winter showed higher total and commercial productivities of carrot roots fertilized with roostertree.

As hortaliças, por possuírem ciclo rápido de produção, demandam adubações em quantidades e momentos ideais para a obtenção da máxima produtividade, sendo a adubação verde uma prática alternativa ao uso de fertilizantes minerais. O presente estudo foi realizado com o objetivo de avaliar os efeitos de diferentes quantidades de biomassa de flor-de-seda [Calotropis procera (Ait.) R. Br.] e seus tempos de incorporação, em duas épocas de cultivo, no desempenho agronômico da cenoura. O experimento foi conduzido em campo experimental pertencente à Universidade Federal Rural de Pernambuco (UFRPE), nos períodos outono-inverno (março a julho de 2012) e primavera-verão (setembro a dezembro de 2012). O delineamento experimental utilizado foi em blocos casualizados, com três repetições. Os tratamentos foram arranjados em esquema fatorial 4 x 4, com o primeiro fator constituído por quatro quantidades de biomassa de flor-de-seda (5,4; 8,8; 12,2 e 15,6 t ha-1 em base seca), e o segundo fator, por quatro tempos de incorporação ao solo deste adubo (0, 10, 20 e 30 dias antes da semeadura da cenoura - DAS). A cultivar de cenoura utilizada foi a Brasília. Foram avaliados a altura de plantas, número de folhas por planta, massa seca de raízes, produtividades total e comercial de raízes. O melhor desempenho agronômico da cenoura cv. Brasília foi obtido com a quantidade de flor-deseda de 15,6 t ha-1, no tempo de incorporação ao solo de 10 dias antes da semeadura. O cultivo no outono-inverno promoveu maiores produtividades total e comercial às raízes de cenoura adubada com flor-de-seda.

Agronomic and environmental implications of using a By-Product of the Intermediate Tanning Processes as Nitrogen Fertilizer

Nitrogen (N) is an important nutrient for agriculture, and Brazil is heavily dependent on N imports. A by-product of the intermediate processes of tanning (BPIPT) may be used as an N fertilizer which will reduce this dependency, but its chromium (Cr) content is a matter of concern. This work assessed Cr (III, VI) and N (total, inorganic) contents in four soil samples with contrasting characteristics (especially with respect to their content of manganese (Mn), a potential Cr(III) oxidant), following the addition of the BPIPT. Chemical and microbiological indicators of soil quality were measured to assess the agronomic and environmental implications of the BPIPT addition in Brazilian soils. Our results indicate that the BPIPT is a promising source of N. The originally available Mn content in the soil did not influence the effect of the BPIPT on soil Cr(VI) content. Finally, microbial activity was generally stimulated after BPIPT addition to the soil. This information is relevant because: 1) it shows that the beneficial use of the BPIPT as an N fertilizer is important for adding value to a by-product with agronomic potential; and 2) it indicates that, at the dosage of the BPIPT used in this study (2.5 g kgsoil-1), the typical increases in the soil concentration of labile Cr (0-25 mg kgsoil-1) and Cr(VI) (0-0.8 mg kgsoil-1) due to the application of the BPIPT are not detrimental to biological activity in the soil. However, further investigations are still necessary to evaluate the mobility of these Cr species in the soil and possible risks of groundwater contamination, which were not addressed in this study.

Agronomic and environmental implications of using a By-Product of the Intermediate Tanning Processes as Nitrogen Fertilizer

Nitrogen (N) is an important nutrient for agriculture, and Brazil is heavily dependent on N imports. A by-product of the intermediate processes of tanning (BPIPT) may be used as an N fertilizer which will reduce this dependency, but its chromium (Cr) content is a matter of concern. This work assessed Cr (III, VI) and N (total, inorganic) contents in four soil samples with contrasting characteristics (especially with respect to their content of manganese (Mn), a potential Cr(III) oxidant), following the addition of the BPIPT. Chemical and microbiological indicators of soil quality were measured to assess the agronomic and environmental implications of the BPIPT addition in Brazilian soils. Our results indicate that the BPIPT is a promising source of N. The originally available Mn content in the soil did not influence the effect of the BPIPT on soil Cr(VI) content. Finally, microbial activity was generally stimulated after BPIPT addition to the soil. This information is relevant because: 1) it shows that the beneficial use of the BPIPT as an N fertilizer is important for adding value to a by-product with agronomic potential; and 2) it indicates that, at the dosage of the BPIPT used in this study (2.5 g kgsoil-1), the typical increases in the soil concentration of labile Cr (0-25 mg kgsoil-1) and Cr(VI) (0-0.8 mg kgsoil-1) due to the application of the BPIPT are not detrimental to biological activity in the soil. However, further investigations are still necessary to evaluate the mobility of these Cr species in the soil and possible risks of groundwater contamination, which were not addressed in this study.(AU)

Nitrogen during the establishment period of Mombasa grass / Nitrogênio em períodos do estabelecimento de capim Mombaça

The aim of this study was to investigate the effect of nitrogen (N) concentration during the establishment period of Mombasa grass (Panicum maximum Jacq.). The experiment was conducted using four different N concentrations (0, 30, 60 and 90 kg N/ha) during the establishment period in order to evaluate the effect of nitrogen on the plant. These effects were assessed using different indexes, including the efficiency of nitrogen use and agricultural, physiological and nutritional efficiencies. We also determined the total dry matter and nitrogen accumulation in the plant. The recovery of applied N and the agronomic efficiency of Mombasa grass were found to be greater with increasing N concentrations, and all indexes tested were found to be affected by the concentration of applied N. Based on the indexes studied, 90 kg N/ha was found to be most suitable for Mombasa grass during the establishment period.(AU)

O presente trabalho teve como objetivo estudar o efeito de doses de nitrogênio (N) em pasto de capimMombaça (Panicum maximum Jacq.) durante o período de estabelecimento. Foi realizado experimento com quatro doses de N (0, 30, 60, 90 kg.ha-1), durante o período de estabelecimento, para avaliação do efeito do nitrogênio na planta, através de índices de eficiência de utilização, eficiência agronômica, fisiológica e nutricional, avaliou-se ainda a matéria seca total e o acúmulo de nitrogênio na planta. Concluiu-se que a recuperação do N aplicado e a eficiência agronômica pelo capim Mombaça aumentou com o incremento das doses. Sendo que, para todos os índices ocorreu influência das doses aplicadas. A dose de 90 kg de N.ha-1, com base nos índices estudados, é a mais indicada para o período de estabelecimento do capim-Mombaça.(AU)

Nitrogen during the establishment period of Mombasa grass / Nitrogênio em períodos do estabelecimento de capim Mombaça

The aim of this study was to investigate the effect of nitrogen (N) concentration during the establishment period of Mombasa grass (Panicum maximum Jacq.). The experiment was conducted using four different N concentrations (0, 30, 60 and 90 kg N/ha) during the establishment period in order to evaluate the effect of nitrogen on the plant. These effects were assessed using different indexes, including the efficiency of nitrogen use and agricultural, physiological and nutritional efficiencies. We also determined the total dry matter and nitrogen accumulation in the plant. The recovery of applied N and the agronomic efficiency of Mombasa grass were found to be greater with increasing N concentrations, and all indexes tested were found to be affected by the concentration of applied N. Based on the indexes studied, 90 kg N/ha was found to be most suitable for Mombasa grass during the establishment period.

O presente trabalho teve como objetivo estudar o efeito de doses de nitrogênio (N) em pasto de capimMombaça (Panicum maximum Jacq.) durante o período de estabelecimento. Foi realizado experimento com quatro doses de N (0, 30, 60, 90 kg.ha-1), durante o período de estabelecimento, para avaliação do efeito do nitrogênio na planta, através de índices de eficiência de utilização, eficiência agronômica, fisiológica e nutricional, avaliou-se ainda a matéria seca total e o acúmulo de nitrogênio na planta. Concluiu-se que a recuperação do N aplicado e a eficiência agronômica pelo capim Mombaça aumentou com o incremento das doses. Sendo que, para todos os índices ocorreu influência das doses aplicadas. A dose de 90 kg de N.ha-1, com base nos índices estudados, é a mais indicada para o período de estabelecimento do capim-Mombaça.

Nitrogen during the establishment period of Mombasa grass / Nitrogênio em períodos do estabelecimento de capim Mombaça

The aim of this study was to investigate the effect of nitrogen (N) concentration during the establishment period of Mombasa grass (Panicum maximum Jacq.). The experiment was conducted using four different N concentrations (0, 30, 60 and 90 kg N/ha) during the establishment period in order to evaluate the effect of nitrogen on the plant. These effects were assessed using different indexes, including the efficiency of nitrogen use and agricultural, physiological and nutritional efficiencies. We also determined the total dry matter and nitrogen accumulation in the plant. The recovery of applied N and the agronomic efficiency of Mombasa grass were found to be greater with increasing N concentrations, and all indexes tested were found to be affected by the concentration of applied N. Based on the indexes studied, 90 kg N/ha was found to be most suitable for Mombasa grass during the establishment period.

O presente trabalho teve como objetivo estudar o efeito de doses de nitrogênio (N) em pasto de capim-Mombaça (Panicum maximum Jacq.) durante o período de estabelecimento. Foi realizado experimento com quatro doses de N (0, 30, 60, 90 kg.ha-1), durante o período de estabelecimento, para avaliação do efeito do nitrogênio na planta, através de índices de eficiência de utilização, eficiência agronômica, fisiológica e nutricional, avaliou-se ainda a matéria seca total e o acúmulo de nitrogênio na planta. Concluiu-se que a recuperação do N aplicado e a eficiência agronômica pelo capim Mombaça aumentou com o incremento das doses. Sendo que, para todos os índices ocorreu influência das doses aplicadas. A dose de 90 kg de N.ha-1, com base nos índices estudados, é a mais indicada para o período de estabelecimento do capim-Mombaça.

Eficiência de genótipos de Brachiaria brizanthaStapf. (Syn: Urochloa brizantha) na produção de biomassa sob aplicação de fósforo / Efficiency of genotypes of Brachiaria brizanthaStapf. (Syn: Urochloa brizantha) in biomass production under phosphorus application

Este trabalho teve como objetivo avaliar a produção de biomassa e a eficiência agronômica em função do fornecimento de fósforo em diferentes genótipos de Brachiaria brizantha. O delineamento experimental utilizado foi inteiramente casualizado, em que os oito tratamentos consistiram em cinco variedades (Arapoty, Capiporã, Marandu, Piatã e Xaraés) e três acessos do banco de germoplasma do Centro Nacional de Pesquisa em Gado de Corte (B5, B10 e B12), em função da aplicação ou não de fósforo. As plantas foram cultivadas sob solo originalmente com 4,1mg dm-3 de fósforo. Avaliou-se a massa seca da raiz (MSR), folha (MSF), parte aérea (MSPA) e a eficiência agronômica (EA). Os dados obtidos foram submetidos ao teste de Doon ao nível de 5% de probabilidade. A produção de MSR foi incrementada pela aplicação de P nas variedades Arapoty, Capiporã, Piatã e Xaraés, em que os valores médios sem P foram de 5,1; 7,4; 7,2 e 5,8g vaso-1, enquanto com aplicação de P foram de 9,4; 10,6; 11,9 e 8,4g vaso-1, respectivamente. Para as variáveis MSF e MSPA, o P promoveu incremento da produção de todos os genótipos, produzindo em média 2,1 e 2,8g vaso-1, respectivamente, sem o fornecimento de P, ao passo que, com o fornecimento de P, produziu 3,8 e 5,5g vaso-1, respectivamente, para MSF e MSPA. Os genótipos Arapoty e B5 foram os mais eficientes no uso de P. O genótipo B12 apresentou maior adaptação para cultivo em solos com baixas concentrações de P, enquanto a variedade Arapoty sobressaiu-se quando realizada aplicação de adubo fosfatado. A variedade Arapoty e o genótipo B5 apresentaram maior eficiência no uso de P, podendo-se indicar esses materiais para programas de melhoramento dessa espécie.

This study aimed to evaluate biomass production and agronomic efficiency as a result of the supply of phosphorus in different genotypes of Brachiaria brizantha. The experimental design was completely randomized, with eight treatments consisting of five varieties (Arapoty, Capiporã, Marandu, and Piata Xaraés) and three accessions of the genebank of the Centro Nacional de Pesquisa em Gado de Corte (B5, B10 and B12) with the application or not of phosphorus. The plants were grown in soil originally with 4.1 mg dm-3phosphorus. We evaluated the root dry mass (MSR), leaf (MSF), shoot (MSPA) and agronomic efficiency (EA). Data were tested for Doon's at 5% probability. MSR production was increased by the application of P in Arapoty, Capiporã, and Piata Xaraés varieties, where the average values without phosphorus were 5.1, 7.4, 7.2 and 5.8g pot-1 while with P application they were 9.4, 10.6, 11.9 and 8.4g pot-1, respectively. For both variables MSF and MSPA, P promoted increased production of all genotypes, producing on average 2.1 and 2.8g pot-1 respectively, without the supply of P, whereas with the supply of P it produced 3.8 and 5.5g pot-1, respectively for MSF and MSPA. Both genotypes Arapoty and B5 were the most efficient in the use of P. The B12 genotype showed greater adaptation for growing in soils with low concentrations of P, while the Arapoty variety excelled when performed applying phosphate fertilizer. The genotypes B5 and Arapoty had higher P use efficiency, being able to indicate these materials for breeding programs of this species.

Eficiência de genótipos de Brachiaria brizanthaStapf. (Syn: Urochloa brizantha) na produção de biomassa sob aplicação de fósforo / Efficiency of genotypes of Brachiaria brizanthaStapf. (Syn: Urochloa brizantha) in biomass production under phosphorus application

Este trabalho teve como objetivo avaliar a produção de biomassa e a eficiência agronômica em função do fornecimento de fósforo em diferentes genótipos de Brachiaria brizantha. O delineamento experimental utilizado foi inteiramente casualizado, em que os oito tratamentos consistiram em cinco variedades (Arapoty, Capiporã, Marandu, Piatã e Xaraés) e três acessos do banco de germoplasma do Centro Nacional de Pesquisa em Gado de Corte (B5, B10 e B12), em função da aplicação ou não de fósforo. As plantas foram cultivadas sob solo originalmente com 4,1mg dm-3 de fósforo. Avaliou-se a massa seca da raiz (MSR), folha (MSF), parte aérea (MSPA) e a eficiência agronômica (EA). Os dados obtidos foram submetidos ao teste de Doon ao nível de 5% de probabilidade. A produção de MSR foi incrementada pela aplicação de P nas variedades Arapoty, Capiporã, Piatã e Xaraés, em que os valores médios sem P foram de 5,1; 7,4; 7,2 e 5,8g vaso-1, enquanto com aplicação de P foram de 9,4; 10,6; 11,9 e 8,4g vaso-1, respectivamente. Para as variáveis MSF e MSPA, o P promoveu incremento da produção de todos os genótipos, produzindo em média 2,1 e 2,8g vaso-1, respectivamente, sem o fornecimento de P, ao passo que, com o fornecimento de P, produziu 3,8 e 5,5g vaso-1, respectivamente, para MSF e MSPA. Os genótipos Arapoty e B5 foram os mais eficientes no uso de P. O genótipo B12 apresentou maior adaptação para cultivo em solos com baixas concentrações de P, enquanto a variedade Arapoty sobressaiu-se quando realizada aplicação de adubo fosfatado. A variedade Arapoty e o genótipo B5 apresentaram maior eficiência no uso de P, podendo-se indicar esses materiais para programas de melhoramento dessa espécie.(AU)

This study aimed to evaluate biomass production and agronomic efficiency as a result of the supply of phosphorus in different genotypes of Brachiaria brizantha. The experimental design was completely randomized, with eight treatments consisting of five varieties (Arapoty, Capiporã, Marandu, and Piata Xaraés) and three accessions of the genebank of the Centro Nacional de Pesquisa em Gado de Corte (B5, B10 and B12) with the application or not of phosphorus. The plants were grown in soil originally with 4.1 mg dm-3phosphorus. We evaluated the root dry mass (MSR), leaf (MSF), shoot (MSPA) and agronomic efficiency (EA). Data were tested for Doon's at 5% probability. MSR production was increased by the application of P in Arapoty, Capiporã, and Piata Xaraés varieties, where the average values without phosphorus were 5.1, 7.4, 7.2 and 5.8g pot-1 while with P application they were 9.4, 10.6, 11.9 and 8.4g pot-1, respectively. For both variables MSF and MSPA, P promoted increased production of all genotypes, producing on average 2.1 and 2.8g pot-1 respectively, without the supply of P, whereas with the supply of P it produced 3.8 and 5.5g pot-1, respectively for MSF and MSPA. Both genotypes Arapoty and B5 were the most efficient in the use of P. The B12 genotype showed greater adaptation for growing in soils with low concentrations of P, while the Arapoty variety excelled when performed applying phosphate fertilizer. The genotypes B5 and Arapoty had higher P use efficiency, being able to indicate these materials for breeding programs of this species.(AU)

Sistemas de cultivo antecessores e doses de nitrogênio em cobertura no feijoeiro em plantio direto / Cover crop systems and nitrogen topdressing on common bean in no tillage

O objetivo do trabalho foi avaliar a formação de palhada e recobrimento do solo em sistemas de cultivo representados por milho, Urochloa ruziziensis e consórcio entre ambos, e sua influência no desempenho produtivo e eficiência agronômica do feijoeiro em sucessão submetido a diferentes doses de nitrogênio em cobertura. Os experimentos foram conduzidos em Latossolo Vermelho eutróférrico, no segundo ano após implantação do sistema de plantio direto, em Jaboticabal (SP). Foi utilizada a cultivar de feijoeiro IPR 139 em parcelas subdivididas, com três repetições, dispostas em blocos casualizados. As parcelas foram compostas por três sistemas de cultivos, representados por milho exclusivo, milho consorciado com U. ruziziensis e U. ruziziensis exclusiva (verão 2009/10) antecedendo a cultura do feijão irrigado, tendo como subparcelas cinco doses de nitrogênio (0, 40, 80, 120 e 160 kg ha-1) aplicadas em cobertura no estádio V4-4. O uso de U. ruziziensis num sistema de sucessão de culturas, seja de forma exclusiva ou consorciada com o milho favorece a formação de palhada suficiente para o total recobrimento da superfície do solo, possibilitando produtividade de grãos similar ao milho exclusivo. O feijoeiro em sucessão ao consórcio não respondeu à adubação nitrogenada em cobertura, diferentemente ao observado na sucessão com milho exclusivo, onde a produtividade de grãos foi positivamente influenciada pela adubação nitrogenada em cobertura. Observou-se redução na eficiência de uso do nitrogênio com incremento da dose do nutriente em cobertura.

The objective of this work was to evaluate the grass cover crop production in crop systems involving maize and Urochloa ruziziensis, and the influence of topdressing nitrogen rates in the yield and agronomic efficiency on common-bean cultivated in succession in no-tillage. The experiments were conducted in Jaboticabal-SP, in a eutrophic red latosol, in the second year of no-tillage system implementation. The IPR 139 cultivar was used in split plot design with three replications, in randomized block. The plots had been composed for three crop systems in the summer season, with maize exclusive, maize intercropped with U. ruziziensis and U. ruziziensis exclusive. The subplots had been constituted for five nitrogen rates (0, 40, 80, 120 and 160 kg ha-1), applied as topdressing at V4-4 in irrigated common-bean cultivated in the winter-spring season. The use of U. ruziziensis in crops systems, exclusive or intercropped with maize favors the grass cover crop production sufficiently to total soli surface covered, possibility similar grain yield compared to maize exclusive. The topdressing nitrogen application doesn't affect the common-bean yield in succession to maize and U. ruziziensis intercropped. The increase of nitrogen rates in common-bean in succession to maize exclusive improves the yield, although decreases the agronomic efficiency.

Doses de potássio em cobertura na primeira soca da cultura da cana-de-açúcar cultivada no norte matogrossense / Doses of potassium in coverage in the first cane ratoon of sugar cane crop cultivated in north matogrossense

A cultura da cana-de-açúcar vem sendo cultivada em todas as regiões do país, ocupando diferentes tipos de solos. A região norte Matogrossense possui condições climáticas muito propícias para a cultura, porém tem-se alcançado baixas produtividades em função da não aplicação de fertilizantes ou de doses ineficientes. Sendo o potássio o elemento mineral absorvido em maiores quantidades pela cultura, objetivou-se com este trabalho avaliar o efeito de doses crescentes do nutriente aplicadas em cobertura no segundo ciclo da variedade de cana-de-açúcar IAC86-2480. O delineamento experimental utilizado foi o de blocos casualizados com quatro repetições. As doses de potássio foram: 0; 60; 120; 180 e 240 kg ha-1 de K2O. Avaliou-se o ºBrix, diâmetro, massa, altura e produtividade de colmos. Não houve efeito significativo para a variável ºBrix em resposta às doses de potássio, já as demais, apresentaram resposta quadrática. A dose de máxima eficiência agronômica foi de 150 kg ha-1 de K2O obtendo produtividade de 85 t ha-1 de colmos, representando 25% de acréscimo de produtividade.

The sugar cane crop has been cultivated in all regions of the Brazil, occupying different soil types. The north region of Mato Grosso has favorable climate conditions for the culture, however, has been achieved low productivity due to the not application of fertilizer and inefficient doses. Being the potassium the mineral element absorbed in large amount by culture. Aimed to with this work to evaluate the effect of growing doses of the nutrient applied in coverage in the second cycle of the variety of sugar cane IAC86-2480. The experimental design was randomized blocks, with four replications. The Potassium doses were: 0; 60; 120; 180 e 240 kg ha-1 of K2O. Was evaluated the oBrix, diameter, weigth, height and productivity of stalk. No was significant effects for the variable oBrix in response to potassium doses, since to others had response quadratic. The dose of maximum agronomic efficiency was of 150 kg ha-1 de K2O obtaining productivity of 85 t ha-1 of stalk, representing 25% increase in productivity.

Economic analysis of cucumber and lettuce intercropping under greenhouse in the winter-spring

The economical analysis complements the evaluation of the intercrop systems efficiency, considering besides the physical production of crops, the price of products according to their quality classification and time of the year. Intercropping systems of lettuce and cucumber in two plant populations under greenhouse were economically evaluated in winter-spring, in Jaboticabal City, São Paulo State, Brazil. The total operating cost (TOC) of cucumber and lettuce as sole crop and intercropping were estimated, as well as gross revenue (GR) and operating profit (OP). The labor for the crops was the component with greater participation in the TOC of crops in intercropping and single crop. Greater GR and OP were observed in intercrops established by transplanting lettuce and cucumbers on the same day. Considering the operating profit and the land efficient ratio, it is recommended the intercropping of lettuce transplanted until 10 days after the transplanting (DAT) of cucumber with two rows per plot, and at 0 DAT of cucumber grown with a row plot.

A análise econômica complementa a avaliação da eficiência dos cultivos consorciados, considerando além da produção física das culturas, o preço dos produtos segundo sua classificação qualitativa e época do ano. Avaliou-se economicamente consórcios de alface crespa e pepino, em duas populações de plantas, no inverno-primavera, em casa de vegetação, em Jaboticabal, SP, Brasil. Foram calculados o custo operacional total (COT), a receita bruta (RB) e o lucro operacional (LO) das culturas do pepino e alface em monocultura e em consórcio. A mão-de-obra foi a componente com maior participação no COT das culturas em consórcio e monocultura. Maiores RB e LO foram observadas nos cultivos consorciados estabelecidos com o transplante da alface e do pepino no mesmo dia, independente da densidade populacional. Considerando-se o lucro operacional e o índice de uso eficiente da área, recomenda-se o cultivo consorciado com transplante da alface até 10 dias após o transplante (DAT) do pepino, com duas linhas, e ao 0 DAT do pepino cultivado com uma linha no canteiro.

Productivity and efficiency of nitrogen fertilization in maize under different levels of urea and NBPT-treated urea / Produtividade e eficiência da adubação nitrogenada em milho sob doses de uréia comum e com NBPT

The management of nitrogen fertilization is complex due to the various transformations of the nitrogen that occur in the soil-plant-atmosphere system, reducing the efficiency of the fertilization, productivity and the profit margin of the maize production areas. This study aimed to evaluate the effect of different levels of common urea and urea treat with NBPT [N-(n-butyl) thiophosphoric triamide] on the productivity and efficiency of the nitrogen fertilization in maize, correlated with simple economic analysis. The design of the field experiment was in randomized complete blocks with six repetitions, in a 2 x 4 factorial outline, made up of by two sources of nitrogen (urea and NBPT-treated urea) and four levels of nitrogen as top dressing (60, 120, 180 and 240 kg ha-1). The sources and applied nitrogen levels influenced the productivity and the leaf and grain nitrogen contents, while the production components (size and diameter of the ear, and percentage of straw and cob) were not altered. The agronomic efficiency of the nitrogen fertilization decreased with the increase of the applied nitrogen levels. The highest gross profit margin in the maize culture is obtained with 180 kg ha-1 of nitrogen supplied in the NBPT-treated urea.

O manejo da adubação nitrogenada é complexo em razão das diversas transformações do nitrogênio que ocorrem no sistema solo-planta-atmosfera, diminuindo a eficiência da adubação, produtividade e a margem de lucro das áreas de produção de milho. Neste trabalho, objetivou-se avaliar o efeito de diferentes doses de uréia comum e com NBPT [N-(n-butyl) thiophosphoric triamide] na produtividade e eficiência da adubação nitrogenada na cultura do milho, correlacionado com análise econômica simples. O delineamento experimental foi em blocos completos casualizados com seis repetições, em esquema fatorial 2 x 4, constituídos por duas fontes de N (uréia comum e uréia tratada com NBPT) e quatro doses de nitrogênio em cobertura (60, 120, 180 e 240 kg ha-1). As fontes e doses de nitrogênio influenciaram na produtividade e nos teores de N da folha e dos grãos, enquanto que os componentes de produção (tamanho e diâmetro da espiga e porcentagem de palha e sabugo) não foram alterados. A eficiência agronômica da adubação nitrogenada diminuiu com o aumento das doses de N aplicadas em cobertura. A maior margem bruta de ganho da cultura do milho é obtida com aplicação de uréia tratada com NBPT, na dosagem de 180 kg ha-1.

Crescimento e produção de grãos da soja sob diferentes doses e fontes de fósforo em solos distintos / Soybean growth and yield under different doses and sources of phosphorus on distinct soils

A fertilidade dos solos das regiões tropicais é limitada pela baixa disponibilidade de fósforo e pela indisponibilização de boa parte do mesmo fornecido na adubação. Ainda existem muitas divergências sobre a melhor forma de utilização das diversas fontes fosfatadas disponíveis no Brasil. Objetivou-se, neste experimento, avaliar a produção de soja, sob a aplicação de diferentes doses e adubos fosfatados em dois tipos de solo. O trabalho foi realizado em casa de vegetação do Departamento de Ciência do Solo da Universidade de Lavras, em vasos de 3 dm³. Utilizaram-se dois solos sob cerrado: Neossolo Quartzarênico e Latossolo Vermelho Distroférrico típico. Foram testadas oito fontes (superfosfato triplo-ST, termofosfato magnesiano-TF, quatro fosfatos reativos importados: FR1, FR2, FR3 e FR4 e dois fosfatos naturais nacionais- FN1 e FN2) e quatro doses (0, 100, 300 e 600 mg dm-3) de fósforo, utilizando-se a soja como planta-teste. As fontes de solubilidade mais elevada ocasionaram as maiores produções e índices de eficiência em relação aos fosfatos naturais. Os fosfatos naturais importados e o FN2 apresentaram-se mais promissores em fornecer P para a cultura da soja, em relação ao superfosfato triplo, mesmo no primeiro cultivo, principalmente em solo com maior poder tampão de fósforo. A capacidade tampão de fósforo dos solos influenciou a eficiência das fontes de fósforo na cultura da soja.

The fertility of soils in tropical areas is limited by the low availability of phosphorus as well as by the unavailability of a great proportion of phosphorus supplied with fertilization. There are still some divergences about the best way of using the different sources of phosphorus available in Brazil. The aim of this experiment was to evaluate the soybean production as a result of the application of different phosphorous doses and fertilizers on two types of soils. The work was carried out in a greenhouse at Soil Science Department, Federal University of Lavras, in vases of 3 dm³ using two kinds of soils: Dystroferric Red Latosol and Quartzarenic Neosols. Eight sources (triple superphosphate-TF, four foreign reactive rock phosphate: FR1, FR2, FR3, and FR4 and two national rock phosphate FN1 and FN2) and four doses (0, 100, 300, and 600 mg dm-3) were applied. Soybeans were used as test plant. Sources with higher solubility showed the highest production and efficiency than natural phosphate. The natural phosphate imported from other countries and FN2 showed good results in supplying P for the soybeans, when compared to the triple superphosphate, even at the first year of culture, mainly on the soil with higher P buffer power. The phosphorus buffer capacity of the soils affected the efficiency of phosphorus sources on the soybean culture.

Crescimento e nutrição da braquiária em função de fontes de fósforo / Growth and nutrition of marandu-grass as a function of phosphorus sources

Avaliaram-se, em casa de vegetação, as contribuições de diferentes fontes de fósforo (P) aplicadas em amostras de Latossolo Vermelho distroférrico (LVdf) (350 mg dm-3 de P2O5) e de Neossolo Quartzarênico (NQ) (200 mg dm-3 de P2O5), coletadas nos municípios de Lavras (MG) e Itutinga (MG), respectivamente, na produção de matéria seca, no teor e acúmulo de P na parte aérea e raiz da Brachiaria brizantha cv. Marandu. Também foi avaliado o índice de eficiência agronômica (IEA) das fontes. O experimento foi conduzido em um delineamento experimental inteiramente casualizado, em esquema fatorial 2x4 (dois solos e quatro fontes de fósforo (Superfosfato Triplo (ST), Fosfato Reativo de Arad (FR), Fosfato Natural de Araxá (FA), e uma mistura ST+FR - na relação (1:1), com quatro repetições. A dose de fósforo foi baseada no teor de P2O5 total das fontes. Para a produção total de matéria seca e o acúmulo total de P, as fontes de maior solubilidade, como o ST, FR e a mistura ST/FR foram mais eficientes, principalmente no primeiro, terceiro e quarto cortes no LVdf e em todos os cortes no NQ. O teor total de P na braquiária ao final do último corte foi maior quando se aplicaram as fonte FR e ST+FR para o LVdf e, ST e ST+FR para o NQ. As fontes de fósforo influenciaram o IEA nos dois solos, que foi maior para as fontes de maior solubilidade.

The contribution of different phosphorus (P) sources applied, under greenhouse conditions, in a clayey dystrophic Red Latosol - Oxisol (LVdf)(350 mg dm-3 of P2O5) and a sandy Neosol - Entisol (NQ)(200 mg dm-3 of P2O5), collected from Lavras (MG) and Itutinga (MG) counties, respectively, on Braquiaria's (Brachiaria brizantha cv. Marandu) dry matter production, P content and accumulation were evaluated. Also agronomic efficiency index (AEI) of the P sources applied was measured. The experiment was carried out under a completely randomized 4x2 factorial, comparing four P sources (Triple superphosphate - TS, Arad reactive phosphate - RP, Araxá rock phosphate - AP, and a 1:1 ratio mixture TS+RP), with four replicates. The amount of P applied was based on the P2O5 content of each source. The forage was cultivated for four cuts. For total dry matter production and P accumulation, P sources of higher solubility, as TS, RP and TS+RP were more efficient, especially for the first, third and forth cuts in the LVdf soil and for all cuts for the NQ soil. By the last cut, Braquiaria's total P content was higher when RP and TS+RP sources were applied for the LVdf soil and TS and TS+RP for the NQ soil. The different P sources had influence on AEI on both soils, for the LVdf soil as for the NQ soil P sources of higher solubility (RP and TS+RP) presented higher AEI.

Biosolids effectiveness to yield ryegrass based on their nitrogen content

Biosolids have been reported to increase yields and supply plant nutrients. However, complying with health and environmental standards is necessary before applying biosolids to land. Thus, sludge stabilization is required to make biosolids safe enough for their agricultural use. Side effects of stabilization processes on agronomic features of sewage sludge are not quite known, although their understanding is essential for biosolids management. Based on a model equivalent to the Mitscherlich equation, effects of the most common processes for sludge stabilization were evaluated (composting, liming, heat-drying and solar irradiation) in relation to the agronomic effectiveness of biosolids to yield Lolium perenne L. on two tropical soils, with NH4H2PO4 as a reference. Sewage stabilization processes have affected the ability of biosolids to promote plant growth. Their effectiveness was usually higher than fertilizer in a Spodosol and lower in an Oxisol. Solar-irradiated sludge presented the highest effectiveness among the biosolids and reached peak yields at the lowest application rate independent on soil type. Biosolids could efficiently substitute fertilizers and even yield more plant dry matter than the NH4H2PO4 reference, depending on the biosolid and soil type.

Biossólidos têm sido citados como capazes de aumentar a produção de culturas e suprir nutrientes para plantas. Questões sanitárias e ambientais demandam que eles sejam estabilizados para que sejam usados na agricultura. Os efeitos dos processos de estabilização sobre as propriedades agronômicas de biossólidos não são completamente conhecidos, apesar de essenciais para o seu manejo. Baseado em um modelo equivalente à equação de Mitscherlich, este trabalho avaliou os efeitos dos processos mais comuns para a estabilização de lodos de esgotos (compostagem, caleação, secagem térmica e irradiação solar) sobre a eficiência agronômica de biossólidos na produção de Lolium perenne L. em um Esposossolo Carbico órtico arenoso e um Latossolo Vermelho perférrico argiloso, usando NH4H2PO4 como referência. Os processos de estabilização afetaram a eficiência agronômica do lodo de esgoto, sendo freqüentemente mais alta que o tratamento com NH4H2PO4 em um solo arenoso, e mais baixa que a referência em um solo argiloso. O lodo irradiado por sol mostrou a mais alta eficiência agronômica entre os biossólidos testados nos dois solos, e o azevém alcançou a produção de pico com a menor dose de aplicação. Os biossólidos puderam substituir fertilizantes e produzir mais matéria seca que o NH4H2PO4, a depender do tipo de biossólido e do solo.