Maximum soil density of Entisols as a function of silt content / Densidade máxima de Neossolos em função do teor de silte

ABSTRACT: Degradation that occursin agricultural soils causes compaction.Soil density (DS) analysis has been reported to be an unreliable method of measuring the extent of soil compaction, because it varies with the soil granulometric composition and organic matter (OM)content. However, soil relative density (DR) is a good indicator that facilitates the measurement of the degree of compaction and thus, soil comparison and management techniques. Quotient between the DS and its maximum density (Dsmax) gives the DR. This study aimed to assess the effect of the granulometric composition on the physical-hydrological properties of the high-silt containing soils,under no tillage. Samples from disturbed and undisturbed structures of 18 soils were collected from the state of Rio Grandedo Sul following the no-tillage system. Once the granulometric size, OM content, soil density, maximum soil density and relative density were determined,the results indicated a drop in the Dsmax value when silt and MO were added;however, the addition of clay and clay-plus-silt revealed no significant effect. When the silt and MO content increased the soil density decreased. The DR, however, was not affected by either the granulometric composition or OM content. A difference was observed between the DR calculated from the determined Dsmax and that estimated by the Dsmax assessed based on the clay levels.Silt content was reported to exert a different influence on the physical-water properties of the silt soils than the clayey ones.

RESUMO: A compactação é causa de degradação em solos agrícolas. Para mensuração do grau de compactação de um solo a análise da densidade do solo (DS) é insuficiente por ser variável em função da sua composição granulométrica e do seu teor de matéria orgânica do solo (MO). Porém, a densidade relativa (DR) do solo é um indicador que permite a identificação do grau de compactação e, assim, comparar solos e manejos. A DR é obtida pelo quociente entre a DS e a sua densidade máxima (Dsmáx). O objetivo desse trabalho foi avaliar o efeito da composição granulométrica, sobre as propriedades físico-hídricas de solos sob plantio direto com elevado teor de silte. Foram coletadas amostras com estrutura preservada e não preservada de 18 solos do estado do Rio Grande do Sul, sob sistema plantio direto. Determinou-se a composição granulométrica, o teor de MO, a densidade do solo, a densidade do solo máxima e a densidade relativa. Os resultados mostraram que a Dsmáx decresceu com o acréscimo de silte e MO, enquanto argila e argila+silte não tiveram efeito significativo. A densidade do solo diminuiu com o aumento de silte e MO. A DR não foi influenciada pela composição granulométrica e teor de MO. Houve diferença entre a DR determinada a partir da Dsmáx determinada e da calculada pela Dsmáx estimada pelo teor de argila. O teor de silte afeta as propriedades físico-hídricas de solos siltosos de forma distinta do que em solos argilosos.

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.

Experience in Treating Intractable Rheumatism by Yang-palm Therapy / 中国中医药信息杂志

Yang-palm, through early systematic Zhan-zhuang training to raise qi, pats the affected area to extract pathological product outer surface using the distal of 2-5 fingers in palm dorsal. This therapy emphasizes infusing qi and extract silt. The treatment continues when pathological product scatters and disappears, so the short-term and long-term efficacy is significant, and especially suitable for the treatment of TCM arthralgia. This article introduced the clinical therapy in treating two rheumatism patients by Yang-palm, explained process and study method of Yang-palm therapy, and shared treatment experience and explored the basic principles of treatment, with a purpose to provide a new treatment for rheumatism.

Clinical study on treatment of chronic renal failure(blood silt and damp pathogen syndrome) with Shenkang Bolt / 中成药

AIM: To observe the curative efficacy of Shenkang Bolt(SKB) in treating chronic renal failure(CRF) with blood silt and damp pathogen syndrome. METHODS: The randomized,parallel and controlled trial were used.38 cases in treatment group were treated with SKB,and 40 cases in control group were clystered with Chinese herbal medicine.The changes of the cumulative scores of traditional Chinese medicine(TCM) syndrome,the levels of serum creatinine(SCr) and creatinine clearance rate(CCr) before and after treatment in both groups were observed. RESULTS: The total effective rate was 81.5% in the treatment group,but 75% in the control group.The scores of TCM syndrome and the levels of SCr were both significantly decreased(P(0.05)). CONCLUSION: SKB can markedly improve the clinical manifestations of CRF with blood silt and damp pathogen syndrome,decrease the levels of SCr,but increase CCr.There was no difference between Chinese herbal clysis and Shenkang Bolt in curative effect,but it is convenent to take Shenkang Bolt.