Synthesis of enriched biochar as a vehicle for phosphorus in tropical soils

Phosphorus (P) is one of the nutrients that most limits agricultural productivity, especially in tropical soils. Enriched biochar has been proposed to increase the bioavailability of P and other nutrients in the soil. Thus, the objective of this study was to evaluate the availability of P in phosphate biochar (composed of biomass and soil) as a function of the triple superphosphate mixture before and after the pyrolysis process. We produced eight types of enriched biochar via pyrolysis by combining sandy or clayey soil with rice or coffee husk, and by adding triple superphosphate before or after pyrolysis. The heating of the phosphate fertilizer during the pyrolysis process resulted in a higher crystallinity of the phosphates, lower content of labile fractions of P and lower content of available P in phosphate biochars than when the superphosphate was added after pyrolysis. (AU)

Effect of nitrogen, phosphorus and potassium fertilizers on Flos Sophorae Immaturus yield and quality in hilly area of Chongqing / 中国中药杂志

With Sophora japonica at the flowering stage as the object, the effect of nitrogen, phosphorus and potassium fertilizers on the yield composition factors, yield and quality of Flos Sophorae Immaturus (FSI) was studied. The results indicated that in early spring, nitrogen, phosphorus and potassium fertilizer on the amplification rate of S. japonica, FSI yield composition, yield and quality were different significantly, middle to high nitrogen (1.5-2.0 kg/plant) significantly increased the level of panicled clusters, raceme and flower bud number and yield. Phosphorus (1.5-2.0 kg/plant) could significantly increase the total buds of flower number and yield, potassium showed no significant increase in yield and yield components. Comprehensively considering yield and quality of FSI, nitrogen 1.5-2.0 kg/plant, phosphorus 1.5-2.0 kg/plant and potassium 0.6-0.9 kg/plant are appropriate.

Total biomass and essential oil composition of Ocimum gratissimum L. in response to broiler litter and phosphorus / Produção de biomassa e composição do óleo essencial de Ocimum gratissimum L. cultivado em solo com cama-de-frango e fósforo

The aim of this experiment was to evaluate the biomass yield and chemical composition of the essential oil of clove basil in response to doses of broiler litter (0, 5, 10, 15 and 20 t ha-1) added in presence of triple superphosphate (200 kg ha-1) or without it. Before the first harvest, the height of the plants increased significantly (34.42 cm) when 15 tonnes ha-1 broiler litter were added to the soil. However, after resprouting, the plant heights ranged only as a function of the vegetative cycle, with maximum height (76.0 cm) observed at 60 days. Phosphate fertilization also significantly influenced the leaf area (1.771 cm2 plant-1) during the first harvest. The fresh weight of leaves increased linearly in response to the addition of broiler litter (20 ton ha-1) with maximum yields of 1,709 and 7,140 kg ha-1 during the first harvest and regrowth, respectively. On average, the oil content of the leaves was 0.7%, with maximum performance (3.8 L ha-1) when 20 tonnes ha-1 of broiler litter were added on the soil. Eugenol was found to be the major compound of the essential oil (71.65%).

O objetivo do trabalho foi avaliar a produção de biomassa e a composição do óleo essencial da alfavaca-cravo cultivada com adição ao solo de cama-de-frango de corte, na ausência ou presença de fósforo. Foram estudadas cinco doses de cama-de-frango semi-decomposta (0, 5, 10, 15 e 20 t ha-1), na ausência ou presença de fósforo (200 kg ha-1), na forma de superfosfato triplo. A altura das plantas na primeira colheita foi maior sob a dose de 15 t ha-1 de cama-de-frango (34,42 cm), ou sem o uso de fósforo (32,4 cm); na rebrota, a altura variou apenas em função do ciclo, sendo máxima (76,0 cm) aos 60 dias após a rebrota. A adubação fosfatada influenciou significativamente a área foliar da primeira colheita, que foi maior com fósforo (1.771 cm2 planta-1). As produções de massas frescas de folhas cresceram linearmente com as doses de cama-de-frango, com máximas de 1.709 e 7.140 kg ha-1 na primeira colheita e na rebrota, respectivamente, sob 20 t ha -1. O teor de óleo essencial foi em média de 0,7% e o rendimento máximo de 3,8 L ha-1 sob a dose de 20 t ha-1 de cama-de-frango; o principal constituinte foi o eugenol, com teor médio de 71,65%.

Dissolving mechanism of strain P17 on insoluble phosphorus of yellow-brown soil

Strain P17 was a bacterial strain identified as Bacillus megaterium isolated from ground accumulating phosphate rock powder. The fermentation broth of strain P17 and the yellow-brown soil from Nanjing Agricultural University garden were collected to conduct this study. The simulation of fixed insoluble phosphorous forms after applying calcium superphosphate into yellow-brown soil was performed in pots, while available P and total P of soil were extremely positive correlative with those of groundwater. Then the dissolving effect of strain P17 on insoluble P of yellow-brown soil was studied. Results showed that Bacillus megaterium strain P17 had notable solubilizing effect on insoluble phosphates formed when too much water-soluble phosphorous fertilizer used. During 100 days after inoculation, strain P17 was dominant. Until the 120th day, compared with water addition, available P of strain P17 inoculation treated soil increased by 3 times with calcium superphosphate addition. Besides available P, pH, activity of acid and alkaline phosphatase and population of P-solubilizing microbes were detected respectively. P-solubilizing mechanism of P-solubilizing bacteria strain P17 seems to be a synergetic effect of pH decrease, organic acids, phosphatase, etc.

Desempenho ponderal de bovinos Nelore suplementados com fontes alternativas de fósforo / Weight gain of Nelore cattle supplemented with different phosphorus sources

O desempenho produtivo e a possível interferência do flúor sobre a saúde dos animais foram investigados em bovinos Nelore suplementados, por 866 dias, com distintas fontes alternativas de fósforo com diferentes relações fósforo:fluor (P:F). Os tratamentos experimentais foram: Controle negativo (CONTNEG, sem qualquer suplementação com P), fosfato bicálcico (FB 120:1, FB 30:1 e FB 10:1), fosfato monobicálcico (FMBC 60:1), superfosfato triplo (SFT 30:1) e fosfato de rocha de Cajati (FR 10:1). Foram utilizados 49 novilhos, desmamados aos oito meses de idade, castrados e com 230 kg de peso médio, distribuídos em sete piquetes com água e mistura mineral formulada sem P. A dieta padrão foi feita com bagaço de cana (0,03% de P) como volumoso e um concentrado contendo 0,239 % de P oferecido na base de 1% do peso dos animais para permitir um ganho de peso aproximado de 0,50 kg/dia. Até o dia 134, não houve diferença estatística entre os diversos lotes, inclusive para o tratamento CONTNEG, que não recebeu fósforo suplementar na dieta e ganhou 71,6 kg de peso ou 0,633 kg/dia. Após 866 dias de confinamento (2,37 anos), os animais suplementados com o fosfato bicálcico padrão (120:1) ganharam menos peso que os suplementados com as fontes FMCB 60:1, FB 30:1 e SFT 30:1. Até um ano de suplementação fosfórica com fosfato bicálcico padrão (120:1) artificialmente fluoretado com NaF ou com o fosfato de rocha não se detectou danos à saúde ou ao ganho de peso dos animais. As análises de fósforo nos ossos mostraram diferença estatística apenas entre o tratamento CONTNEG e os que tinham fosfato bicálcico. As concentrações de flúor nos ossos se mostraram intimamente associadas à quantidade de flúor disponível nas fontes utilizadas. Conforme a proporção P:F na dieta foi diminuindo, características relacionadas à fluorose dentária ficaram mais evidentes, sendo que os animais que receberam fontes com relação 10:1, apresentaram, ao final do experimento, dentes incisivos permanentes mal formados, quebradiços e com manchas esbranquiçadas.

Weight gain and possible interference of fluoride on animal health was investigated in Nellore cattle supplemented during 866 days with alternative sources of phosphorus with different phosphorus:fluor (P:F) ratios. The five treatments were: (1) Negative control (NC, without any supplemental P), (2) dicalcium phosphate (DCP 120:1, DCP 30:1 and DCP 10:1), (3) monodicalcium phosphate (MDCP 60:1), (4) triple superphosphate (TSF 30:1), and (5) cajati rock phosphate (RP 10:1). We used 49 oxen weaned with 8 months of age and an average weight of 230 kg, distributed into seven paddocks with water and mineral mixture formulated without P. A standard diet consisting of sugar cane bagasse (0.03% P) as roughage and a concentrate containing 0.239% P was provided on 1% of live weight to allow a weight gain of about 0.50 kg/day. Until day 134, there was no statistical difference between the various groups, including the treatment NC which received no supplemental phosphorus in the diet and gained weight of 71.6 kg or 0.633 kg/day. After 866 days of confinement (2.37 years), the oxen supplemented with dicalcium phosphate standard (120:1) gained less weight than those supplemented with sources MDCP 60:1, DCP 30:1 and TSF 30:1. Up to one year of supplementation with dicalcium phosphate artificially fluoridated with NaF or with rock phosphate did not result in damage to health or in weight gain of the animals. Analyses of phosphorus in bones showed statistical difference between treatments, and group NC that did not receive any supplemental P showed the lowest values. The concentration of fluoride in bones proved to be closely related to the amount of fluoride available in the sources used. As the ratio P:F in the diet decreased, characteristic signs related to dental fluorosis became more evident, and the animals that received P supplies with 10:1 ratio showed at the end of the experiment permanent malformed incisor teeth, brittle and whitish stained.

Resposta do feijão-caupi à doses e formas de aplicação de fósforo em Latossolo Amarelo do Estado de Roraima / Response of cowpea (Vigna unguiculata (L. ) Walp. ) to phosphorus fertilization levels and application forms in Yellow Latosol of Roraima State/Brazil

A adubação fosfatada e as formas de aplicação de fertilizantes fosfatados são fatores importantes no manejo das culturas. O objetivo do presente trabalho foi avaliar os efeitos de doses de fósforo e formas de aplicação de fertilizante fosfatado na cultura do feijão-caupi (Vigna unguiculata (L.) Walp) em solo de cerrado do Estado de Roraima. O experimento foi realizado em condições de campo, em Latossolo Amarelo distrocoeso, no Campus do Cauamé da Universidade Federal de Roraima. O delineamento experimental foi o de parcelas subdivididas, com as parcelas principais organizadas em blocos casualizados, com três repetições. As parcelas foram constituídas pelas formas de aplicação do fertilizante fosfatado: a) Lanço - L; b) Sulco simples - SS e c) Sulco duplo - SD. As subparcelas corresponderam às doses da adubação fosfatada: 0; 0,5; 1,0; 1,5 e 2,0 vezes a dose recomendada para adubação de manutenção do feijão-caupi. Houve efeito das doses de fósforo sobre o crescimento e absorção de fósforo pelas plantas. O maior crescimento, produção de vagem por planta, de grãos e absorção de fósforo ocorreu com a aplicação do fertilizante fosfatado aplicado em sulcos duplos.

Phosphorus fertilization and ways of phosphate fertilizers application are important factors considering crop management. This study aimed at assessing the effect of phosphorus rates and phosphate fertilizers application forms on growth and phosphorus uptake of cowpea plants cropped on cerrado soil in the State of Roraima, Brazil. An experiment took place under field conditions, on a Yellow Latosol, at Cauamé Campus of Roraima's Federal University, located in the municipality of Boa Vista/RR. The experimental design was split-plot, in a completely randomized blocks, with three replicates. The plots consisted of the following phosphoric fertilizers application forms: a) broadcasting; b) single furrow and c) double furrow. Sub-plots corresponded to phosphorus doses: 0, 0,5; 1,0; 1,5, and 2,0 times the recommended dose for cowpea maintenance fertilization (60 kg ha-1 of P2O5). There was a significant effect of P rates over plant growth and plant uptake. Application of fertilizer in double furrows promoted higher plant growth, grain yield, and plant phosphorous uptake.