Fractionation of phosphorus in soils amended with poultry manure co-composted with sugarcane and cabbage wastes / Fracionamento de fósforo em solos corrigidos com esterco de aves co-compostado com resíduos de cana de açúcar e repolho

Organic waste recycling is a viable option for reducing energy usage, volume of landfills, air and water pollution, greenhouse gas emissions and preserving natural resources for future use. Composting is an easy and natural bio-degradation process that converts organic wastes into available nutrients for plants. We studied the changes in phosphorus (P) fractions in soils amended with poultry manure co-composted with sugarcane and cabbage wastes. The compost was applied to sandy clay and silt loam soils at 10 and 20 t ha-1. Soils were then incubated at room temperature for 8 weeks when mineralization was expected and analyzed for extractable P fractions. The P fractions in the soils varied in the order HCl-P (Ca+Mg-bound) > H2O-P (water soluble) > NaHCO3-P (readily plant-available P) > NaOH-P (Fe+Albound) and the fractions increased significantly as compost application rates increased and decreased as the amount of sugarcane and cabbage wastes in the compost increased. Phosphorus was less concentrated in the compost containing CW than that containing SW and was higher in sandy clay than silty loam soil. The overall results showed that composting reduced the bio-availability of P from poultry litter and would be beneficial for optimizing P fertility in soil and minimizing losses to the environment.

A reciclagem de resíduos orgânicos é uma opção viável para reduzir o uso de energia, o volume de aterros sanitários, a poluição do ar e da água, as emissões de gases de efeito estufa e a preservação dos recursos naturais para uso futuro. A compostagem é um processo fácil e natural de biodegradação que converte resíduos orgânicos em nutrientes disponíveis para plantas. Estudamos as alterações nas frações de fósforo (P) em solos alterados com esterco de aves de capoeira co-compostada com resíduos de cana de açúcar e repolho. O composto foi aplicado em solos arenosos, argilosos e limosos com 10 e 20 t ha-1. Os solos foram então incubados à temperatura ambiente durante 8 semanas quando a mineralização era esperada e analisada para as frações de P extraíveis. As frações de P nos solos variaram na ordem HCl- P (Ca + Mg-bound) > H2O-P (solúvel em água) > NaHCO3-P ( P prontamente disponível para a planta) > NaOH-P (Fe + Al-bound) e as frações aumentaram significativamente à medida que as taxas de aplicação de composto aumentaram e diminuíram à medida que aumentou a quantidade de resíduos de cana de açúcar e de repolho na compostagem. O fósforo estava menos concentrado no composto contendo CW do que o que continha SW e era mais alto em argila arenosa do que o solo limoso. Os resultados globais mostraram que a compostagem reduziu a biodisponibilidade do P vindo do lixo de aves de capoeira e seria benéfica para otimizar a fertilidade do P no solo e minimizar as perdas para o meio ambiente.

Biochar como enmienda en un oxisol y su efecto en el crecimiento de maíz

Hay una creciente preocupación, a nivel mundial, por la declinación de la calidad de los suelos. Numerosos reportes sugieren la adición de biochar, para incrementar la fertilidad del suelo y la productividad de los cultivos. Se evaluó el efecto de la aplicación de diferentes niveles de biochar, en un oxisol representativo de la Altillanura Colombiana y su efecto en el crecimiento del maíz. Las muestras de suelo fueron recolectadas y tratadas con biochar de cuesco de palma africana procesado, en un reactor termoquímico cilíndrico de lecho fijo; se manejó régimen de flujo concurrente y diferentes temperaturas, para priorizar la obtención de biochar. Se utilizaron dosis de biochar (masa/masa) de 0, 2, 5 y 10% y se compararon con tratamiento con cal. Después de incubación por 45 días bajo condiciones ambientales exteriores, cuatro semillas de maíz (Zea maíz L.) variedad Guacavía fueron sembradas en cada recipiente, sin adición de fertilizante o enmienda. Las unidades experimentales fueron contenedores plásticos de 5kg. El material vegetal, aunque se recolectó a los 90 días después de la siembra, presentaba una fase vegetativa V5. Se analizó absorción de nutrientes por el maíz en planta entera. Independiente, se analizaron muestras del biochar, encontrándose que predominaron las cargas negativas. En la mezcla suelo-biochar, se observó incremento de P, Ca, Mg y K, pero el Na no tuvo incremento; se redujo el Al+3 proporcional a la aplicación de biochar. La absorción de Zn y Mg aumentó notablemente en el maíz, pero también la absorción de Fe se incrementó, a niveles tóxicos.

There is growing concern worldwide for the decline of soil quality. Numerous reports suggest the addition of biochar to increase soil fertility and crop productivity. The effect of applying different levels of biochar in a representative oxisol of Colombian Altillanura and its effect on corn growth was evaluated. Soil samples were collected and treated with African palm shell biochar, thermochemically obtained in a cylindrical fixed bed reactor, in a concurrent flow regime. Different temperatures were handled to prioritize obtaining biochar. Doses of biochar (m/m) of 0, 2, 5 and 10% were used and compared with treatment with lime. After 45 days incubation, under external environmental conditions, seeds of maize (Zea mays L.), Guacavía variety were planted in each container, without addition of fertilizer or amendment. The experimental units were plastic containers of 5kg. Although the plant material was collected 90 days after planting, it presented a vegetative phase V5. Nutrient uptake by corn was analyzed in whole plant. Independent biochar samples were analyzed and found predominance negative charges. In the mix biochar-soil increased P, Ca, Mg and K was observed, but did not increase Na. Al+ 3 proportional to the application of biochar was reduced. The Zn and Mg absorption increased significantly in maize, but also Fe uptake increased to toxic levels.

Isolation and 16S rRNA-Based Identification of Benomyl-Degrading Bacteria.

Laboratory experiments were conducted to isolate and identify Benlate- (Benomyl) degrading microorganisms from two soil types collected from different locations in Khartoum State, Sudan. Benomyl degradation was studied at two temperatures (28 and 40ºC) in soil treated with three Benomyl concentrations (0.032, 3.2 and 8.0mg Benomyl/g soil) and incubated for 360 days. Potential degraders were also tested in mineral salt liquid medium using Benomyl as a sole carbon source. Degradation percentages were then determined and the most efficient Benomyl degraders were identified by amplification with 16S rRNA gene, sequencing and alignment with deposited sequences in the international gene bank. A total of 64 isolates were recovered from the two soil types, with 59 (92.2%) isolates recovered from the clay soil. Thirty four isolates were recovered from clay soil treated with 8.0mg Benomyl/g soil and incubated at 28ºC. The most efficient Benomyl degraders, with degradation percentages in the range of 44-59, were identified as Pseudomonas stutzeri (Two different isolates), Pseudomonas putida, Acinetobacter johnsonii, Brevibacillus invocatus, Bacillus clausii, Lysinibacillus sp. and Agrobacterium radiobacter.