Pod positioning and grain yield of common bean as affected by sowing density, nitrogen fertilization and fertilization depth

The positioning of pods in common bean directly affects grain losses in mechanized harvesting. However, only few studies have assessed facttors that can affect pods positioning. The objective of this work was to determine the effect of plant density, nitrogen fertilization, and fertilization depth on the distribution of pods of the common bean. The field experiments were carried out in two cropping seasons, 2017 and 2018, during the winter period in the Cerrado region. The experimental design was randomized blocks in a 4x2 factorial scheme, with four replications. The treatments consisted of the combination of four sowing densities (5, 10, 15, and 20 plants m-1) with two depths of fertilizer application (6 and 12 cm). The results allowed inferring that the depth of the fertilization does not affect the distribution of pods in the common bean. Plant density does not affect common bean grain yield. More than a quarter of the common bean pods of the BRS FC104 are positioned close to the ground, below 100 mm, in the area where harvester machines operate. Nitrogen fertilization and plant density affect the distribution of pods in common bean plants. At higher doses of N (90 kg ha-1), plant density should be increased. On the other hand, at lower doses (45 kg ha-1), plant density must be reduced. It is concluded that the sowing density can be an efficient strategy to provide the highest positioning of pods in the upper part of the common bean plants, reducing harvest loss.

Screening of Beneficial Microorganisms to Improve Soybean Growth and Yield

Abstract The objective of this research was to identify the best microorganisms, alone or in mixture for total biomass gain (root + shoot), positive change in gas exchange, nutrient uptake (root, shoot and grain) and yield and yield components in the soybean crop. Trial under greenhouse conditions had the experimental design in a completely randomized scheme with 26 treatments and four replicates. The treatments consisted of the rhizobacteria BRM 32109, BRM 32110 and 1301 (Bacillus sp.), BRM 32111 and BRM 32112 (Pseudomonas sp.), BRM 32113 (Burkholderia sp.), BRM 32114 (Serratia sp.), Ab-V5 (Azospirillum brasilense) and 1381 (Azospirillum sp.), and the fungus Trichoderma asperellum (a mix of the isolates UFRA.T06, UFRA.T09, UFRA.T12 and UFRA.T52). Besides, the same isolates were combined in pairs, completing 16 combinations. Control treatments received no microorganism. Microorganisms applied isolated or in combination, provided biomass gain, positive gas exchange, increases in nutrients uptake at the shoot and grain, and improved grain yield and its components than control plants. Stood out the combination Ab-V5 + T. asperellum pool, which provided a 25% improvement in grain yield.

Genotype selection and addition of fertilizer increases grain yield in upland rice in Suriname / Seleção de genótipos e adição de fertilizantes aumenta a produtividade de grãos do arroz de terras altas no Suriname

ABSTRACT The upland rice farmers in Suriname use local varieties and low level technologies in the field. As a result, the upland rice grain yield is low, at about 1 000 kg ha-1. Our objective was to evaluate the use of upland rice cultivars from Suriname and Brazil, and the effect of nitrogen, N, phosphorus, P, and potassium, K, fertilizers on cultivation variables. We undertook four field trials in the Victoria Area, in the Brokopondo District, using a randomized block design each with four replications. The most productive rice varieties were BRS Esmeralda (grain yield 2 903 kg ha-1) and BRS Sertaneja (2 802 kg ha-1). The highest grain yield of 2 620 kg ha-1 was achieved with a top dressing application of 76.41 kg N ha-1 20 days after sowing. For P, the highest grain yield of 3 085 kg ha-1 was achieved with application of 98.06 kg ha-1 P2O5 applied at sowing. An application rate of 31.45 kg ha-1 of K2O at sowing achieved the highest grain yield of 2 952 kg ha-1. Together, these application rates of N, P and K resulted in rice grain yield of about 3 000 kg ha-1, which is three times greater than the national average for upland rice. We demonstrate that the use of improved rice varieties matched to the local conditions, and application of appropriate fertilizers, are management practices that can result in significant increases in rice grain yield in Suriname.

RESUMO Produtores de arroz de terras altas no Suriname usam cultivares locais e baixo nível tecnológico. Assim, a produtividade é baixa (1 000 kg ha-1). Nosso objetivo foi avaliar o uso de cultivares de arroz de terras altas do Suriname e do Brasil, e o efeito de taxas de nitrogênio, N, fósforo, P e potássio, K sobre variáveis de cultivo. Foram instalados quatro ensaios de campo usando em cada experimento o delineamento de blocos casualizados com quatro repetições. As mais produtivas cultivares de arroz foram BRS Esmeralda (produtividade de 2 903 kg ha-1) e a BRS Sertaneja (2 802 kg ha-1). A mais alta produtividade de grãos de 2 620 kg ha-1 foi alcançada pela aplicação em cobertura de 76.41 kg N ha-1, aos 20 dias após a semeadura. Para P, a mais alta produtividade de grãos de 2 620 kg ha-1 foi alcançada com a aplicação de 98.06 kg ha-1 de P2O5 na semeadura. Uma aplicação da dose de 31.45 kg ha-1 K2O na semeadura permitiu o maior rendimento de grãos, 2 952 kg ha-1. Juntas, essas taxas de aplicação proporcionaram rendimento de grãos de arroz em torno de 3 000 kg ha-1, o que é três vezes maior que a média nacional do país para arroz de terras altas. O uso de variedades melhoradas de arroz adaptadas às condições locais, e a aplicação de doses adequadas de nutrientes são práticas de manejo que podem resultar em significativo aumento no rendimento de cultivos de arroz de terras altas no Suriname.

Fertilizers with coated urea in upland rice production and nitrogen apparent recovery / Doses de fertilizantes com ureia revestida na produção de arroz de terras altas e recuperação aparente de nitrogênio

Urea is the most used N fertilizer for upland rice, however, a great percentage of N loss can occur with the use of this fertilizer. The use of products that provide reduction of N loss for urea fertilizers can contribute to increase N use efficiency. The objective of this study was to determine the effect of N rates applied in the form of coated urea in the content and accumulation of N in dry biomass, apparent recovery of nitrogen and grain yield of upland rice. The experimental design was a randomized complete blocks arranged in a 4 x 3 + 1 factorial scheme. The treatments consisted of four sources of N fertilizer [1. Common urea; 2. Polymer-coated urea for slow release of N (PCU); 3. urea with the urease inhibitor N-(n-Butyl) thiophosphoric triamide (NBPT); and 4. urea coated with copper sulfate and boric acid as urease inhibitors (UCCB)], with three fertilization rates (30, 60 and 90 kg ha-1 of N). In addition, we included a control treatment without N application. Coated urea did not provide increases in rice grain yield in relation to common urea. The increasing amount of N resulted in significant increases in rice grain yield (from 3217 to 5548 kg ha-1, 2010/11, and from 3392 to 4560 kg ha-1, 2011/12). The apparent nitrogen recovery rate decreased with the increase in N applied doses.

A ureia é o fertilizante nitrogenado mais utilizado para o arroz de terras altas, no entanto, esse fertilizante tem grande percentual de perda de N. O uso de produtos que proporcionam redução da perda de N em fertilizantes com ureia pode contribuir para aumentar a eficiência de uso do nitrogênio. O objetivo deste estudo foi determinar o efeito de doses de N aplicadas na forma de ureia encapsulada no teor e acúmulo de N na biomassa seca, recuperação aparente de nitrogênio e produtividade de grãos de arroz de terras altas. O delineamento experimental foi em blocos ao acaso no esquema fatorial 4 x 3 + 1. Os tratamentos consistiram de quatro fontes de N fertilizante [1. ureia tradicional; 2. Polímero de ureia revestida para liberação lenta de N (PCU); 3. ureia com o inibidor de urease N- (n-butil) triamida tiofosfórico (NBPT); e 4. ureia revestida com sulfato de cobre e ácido bórico como inibidores de urease (UCCB)], com três doses de fertilizante (30, 60 e 90 kg ha-1 de N). Além disso, incluímos uma testemunha sem aplicação de N. Ureia revestida não forneceu aumentos no rendimento de grãos de arroz em relação à ureia comum. O aumento da quantidade de N resultou em aumentos significativos no rendimento de grãos de arroz (de 3217 para 5548 kg ha-1, 2010/11, e de 3392 para 4560 kg ha-1, 2011/12). A taxa de recuperação aparente de nitrogênio diminuiu com o aumento das doses aplicadas de N.

Adubação silicatada no sulco e nitrogenada em cobertura no arroz de sequeiro e irrigado por aspersão / Silicon in row and nitrogen in topdressing fertilization on rice under dry land and sprinkler irrigation conditions

O objetivo deste trabalho foi avaliar os efeitos da aplicação do silício no sulco de semeadura, combinado com adubação nitrogenada em cobertura, na produtividade de grãos, nos teores de silício no solo, no tecido vegetal e teor de nitrogênio na planta, em condições de sequeiro e irrigado. O delineamento experimental utilizado foi de blocos casualizados com parcelas subdivididas e quatro repetições. Os tratamentos foram constituídos pelos sistemas de cultivo (sequeiro e irrigado) e as subparcelas pela combinação do silício (0 e 100 kg ha-1), tendo como fonte o silicato de Ca e Mg (com 23% de SiO2) e quatro doses de nitrogênio (ureia) em cobertura (0, 30, 60 e 90 kg ha -1). A aplicação de silício no sulco de semeadura demonstrou ser técnica viável, pois proporcionou aumento significativo do teor desse elemento na zona de crescimento radicular da cultura do arroz. A aplicação de silício no sulco não altera o teor do elemento e nem a nutrição nitrogenada em plantas de arroz. A adubação nitrogenada em cobertura reduz os teores de silício e aumenta a nutrição nitrogenada nas plantas de arroz. A aplicação de silício no sulco de semeadura não proporcionou incremento na produtividade de grãos de arroz. Quando não houve limitação hídrica a adubação nitrogenada proporcionou incremento linear na produtividade de grãos, enquanto que sob deficiência hídrica o efeito da fertilização nitrogenada foi limitada.

The objective of this work was to evaluate the effects of silicon application adjusted with nitrogen fertilization via top-dressing on grain productivity, the silicon contents of the soil, in the plant tissue and nitrogen contents in dry and irrigated conditions. The experimental outlining was from designed blocks with subdivided parcels and four repetitions. The treatments consisted of culture system (dry and irrigated) and the under parcels by the combination of silicon (0 and 100 kg ha-1), in magnesium and calcium silicate form (with 23% of SiO2), and four doses of N (urea) via top-dressing (0, 30, 60 and 90 kg ha-1). Silicon application at sowing furrow was a viable technique because it provided significant increase in the content of this element in the root growth of rice. The application of silicon in the sowing furrow did not change the content of the element nor the nitrogen nutrition in rice plants. The nitrogen application reduced the silicon content and increased nitrogen nutrition in rice plants. Silicon application at sowing furrow provided no increase in rice grain yield. When there was no water limitation to nitrogen fertilization enhanced linearly on rice grain yield, whereas under water stress the effect of nitrogen fertilization was limited.