https://socictopen.socict.org/files/original/f4ee0312675f7ecd8971697635744cf6.pdf 1a9af1e545c5191e41523a236a3002c3 Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Agricultura sostenible Description An account of the resource Dominio científico: Agricultura sostenible Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Nitrogen fixation by groundnut and velvet bean and residual benefit to a subsequent maize crop Fixação de nitrogênio por amendoim e mucuna e benefício residual para uma cultura de milho Creator An entity primarily responsible for making the resource Bruno José Rodrigues Alves, Segundo Urquiaga, Ambate Okito, Robert Michael Boddey Description An account of the resource Chemical fertilisers are rarely avaiable to poor farmers, for whom the nitrogen (N) is often the most limiting element for cereal grain production. The objective of this study was to quantify the contribution of biological nitrogen fixation (BNF) to groundnut (Arachis hypogaea) and velvet bean (Mucuna pruriens) crops using the 15N natural abundance (delta15N) technique and to determine their residual effect and that of a natural fallow, on growth and N accumulation by two rustic maize varieties. The contribution of BNF calculated from delta15N data was 40.9, 59.6 and 30.9 kg ha-1, for groundnut, velvet bean and the natural fallow, respectively. The only legume grain harvested was from the groundnut, which yielded approximately 1.000 kg ha-1. The subsequent maize varieties ('Sol de Manhã' and 'Caiana Sobralha') yielded between 1.958 and 2.971 kg ha-1, and were higher after velvet bean for both maize varieties and 'Sol da Manhã' groundnut, followed by 'Caiana' after groundnut and, finally, the natural fallow. For a small-holder producer the most attractive system is the groundnut followed by maize, as, in this treatment, both groundnut and maize grain harvest are possible. However, a simple N balance calculation indicated that the groundnut-maize sequence would, in the long term, deplete soil N reserves, while the velvet bean-maize sequence would lead to a build up of soil nitrogen.Fertilizantes químicos raramente estão disponíveis aos agricultores com poucos recursos econômicos, e assim o N é, freqüentemente, um elemento mais limitante para a produção de grãos. O objetivo deste trabalho foi quantificar a contribuição da fixação biológica de nitrogênio (FBN) às culturas de amendoim (Arachis hypogaea) e mucuna (Mucuna pruriens), por meio da técnica de abundância natural de 15N e determinar o efeito residual das leguminosas e do pousio sobre o crescimento e acumulação de N em duas variedades de milho. A contribuição da FBN calculada a partir dos dados de delta15N, foi de 40,9, 59,6 e 30,9 kg ha-1, respectivamente, para amendoim, mucuna e o pousio. A única leguminosa de grão colhida foi amendoim que produziu aproximadamente 1,000 kg ha-1. A produtividade da cultura de milho (variedades Caiana e Sol da Manhã) variou de 1,958 a 2,971 kg ha-1 de grãos, sendo mais alta após mucuna em ambas as variedades de milho e após amendoim na Sol da Manhã, seguida por Caiana após amendoim e por último o pousio normal. Para pequenos agricultores o sistema mais atrativo é o que inclui amendoim seguido pelo milho, uma vez que duas colheitas de grãos são possíveis. Contudo, o cálculo do balanço de N indicou que a seqüência amendoim-milho diminuiria, a longo-prazo, a reserva de N do solo, enquanto a seqüência mucuna-milho ajudaria a aumentar a reserva de N do solo. Date A point or period of time associated with an event in the lifecycle of the resource 2004 Subject The topic of the resource 15N natural abundance technique, Agricultura Familiar, Arachis hypogaea, Mucuna pruriens, N balance, abundancia natural de 15N, adubos verdes, balanço de N, green manures, rotação de culturas, small-holder producers, zea mays Identifier An unambiguous reference to the resource within a given context 10.1590/S0100-204X2004001200004 Source A related resource from which the described resource is derived Pesquisa Agropecuária Brasileira Publisher An entity responsible for making the resource available Embrapa Informação Tecnológica Coverage The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant Agriculture (General) Relation A related resource <a href="http://www.scielo.br/scielo.php?script=sci_arttext&amp;pid=S0100-204X2004001200004" target="_blank" rel="noreferrer noopener">http://www.scielo.br/scielo.php?script=sci_arttext&amp;pid=S0100-204X2004001200004</a>