2 resultados para [NH4]
em Bioline International
Resumo:
O nitrognio e um dos nutrientes mais demandados pelas espcies vegetais, sua presena no solo, sob formas orgnicas ou minerais disponveis para as plantas, est vinculada qualidade e quantidade dos resduos vegetais aportados ao solo. O estudo teve o objetivo de avaliar a influncia do cultivo do eucalipto e da accia na composio das formas orgnicas e inorgnicas de N e, na abundncia natural de 15N em um Argissolo Amarelo. Para isso, foram coletadas amostras de solo e serapilheira em monocultivos do Eucalyptus urograndis (clone do Eucalyptus urophylla S. T. Blake x Eucalyptus grandis W. Hill ex Spreng) de ciclo curto (sete anos), sistemas de cultivo de rotao com accia ( Acacia mangium Willd.) aps monocultivo de eucalipto, monocultivo de eucalipto de ciclo longo (24 anos) e mata nativa (Mata Atlntica) como condio original de solo do litoral Norte do Esprito do Santo. Foram avaliados os teores de C orgnico total, N total, N-NH4+, N-NO3-, relao C/N, fracionamento do N orgnico e abundncia natural de 15N no solo e serapilheira. Das formas de N-orgnico hidrolisado, o N-amino foi a frao que apresentou maior contribuio (39%), seguida pela frao de N-no identificado (27%), da frao N-amida (18%) e N-hexosamina (15%). O povoamento de accia promoveu menor abundncia natural de 15N e maiores teores de N total e C orgnico no solo e aumentou as formas orgnicas de N-hidrolisado, quando comparado queles de eucalipto de ciclo curto. Isso indica o aumento de formas lbeis de N orgnico no solo para as plantas e reduo da humificao da matria orgnica do solo (MOS) de accia. Nesse sentido, a rotao de cultivos florestais com accia aps eucalipto de ciclo curto contribuiu para o aumento de formas orgnicas no solo, importantes para a nutrio de plantas, por serem potenciais fontes de nutrientes s plantas em curto perodo de tempo.
Resumo:
Biogas can be a clean cooking alternative where biomass is the dominant source of cooking energy and where feedstock for anaerobic digestion is available. By substituting woody biomass for energy, biogas may reduce local deforestation. Tanzania has more than 15.6 million goats. Dairy goats of different breeds are found in the mid- to high altitudes of the country. Population density has made firewood increasingly scarce and there are few energy alternatives in mountainous areas such as in the Uluguru Mountains. In Mgeta ward, Morogoro region, introduction of Norwegian dairy goats in the 1980s has improved livelihoods in the area. In this study, goat manure was assessed as feedstock for biogas and as fertilizer. Field work among small-holder dairy goat farmers in Mgeta was conducted to measure daily manure production, and to provide a basic model for prediction of the quantity of droppings which may be collected by farmers. Biogas and fertilizer potential from goat manure was compared to cow and pig manure. Buswells formula was used to calculate approximate methane yield. The results show that goat manure from Mgeta can yield 167 lkg Volatile Solids-1 (VS). Compared with other substrates approximate methane yield can be ranked as pig > guatemala grass > cow > goat. The average goat of 25 kg in Mgeta leaves 61 kg Total Solids (TS) droppings per year. It was estimated that 15 goats capita-1 would be required to meet the total cooking energy needs of small-holder households in the study location. N:P:K content in goat manure (TS) is 2:1:1, similar to cow and pig manure. Goat droppings had to be macerated to reduce particle size for anaerobic digestion. Biogas from dairy goats could be combined with the year-round irrigated horticulture production in Mgeta. Vegetable gardens in the slope below the digesters could be fertilized by gravitation with the NH4+-rich bioslurry, to save labour and increase yields.
