{"id":116593,"date":"2009-04-17T13:39:00","date_gmt":"2009-04-17T13:39:00","guid":{"rendered":"http:\/\/weblogs.madrimasd.org\/\/universo\/archive\/2009\/04\/17\/116593.aspx"},"modified":"2010-01-22T03:51:47","modified_gmt":"2010-01-22T02:51:47","slug":"las-granjas-del-futuro-policultivos-suelos-agua","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/universo\/2009\/04\/17\/116593","title":{"rendered":"Las Granjas del Futuro: Policultivos Suelos-Agua"},"content":{"rendered":"

Resulta cada vez m\u00e1s habitual leer este tipo de noticias en la prensa cient\u00edfica de EE.UU. <\/span>Mientas<\/span><\/b> por estos lares hispanos olvidamos <\/span>la agricultura diversificada de nuestros antepasados, en Estados Unidos la reinventan<\/span><\/b>. Ya os hemos comentado en otros post, como en este<\/font><\/a>, que la<\/span> agricultura industrial cada vez se encuentra m\u00e1s cuestionada<\/span><\/b>, incluso frente a policultivos bien planificados. No hablamos tan solo del medio ambiente, sino incluso de <\/span>productividad<\/span><\/b>. En la noticia de <\/span>Sciencedaily<\/span><\/b> que os mostramos abajo, se muestra como los cient\u00edficos de aquel pa\u00eds, <\/span>ante la urgencia de los agricultores de Carolina del Norte, por sufrir un descenso en la demanda de tabaco, y <\/span><\/b>desear un aumento en la diversificaci\u00f3n de sus plantaciones, se pusieron a \u201cpensar\u201d. Y he te aqu\u00ed que algunos descubrieron que en las <\/span>charcas (Pozas, albercas) que utilizaban para el riego pod\u00edan criarse unos \u201ccangrejos azules\u201d<\/span><\/b>, que tambi\u00e9n viven por el litoral y son <\/span>muy demandados por los estadounidenses<\/span><\/b>. Al parecer pueden proporcionar <\/span>tres cosechas al a\u00f1o y no son baratos<\/span><\/b> precisamente. Su sabor, al parecer, tampoco desmerece a los que actualmente comen. <\/span>De este modo, el agricultor deviene a su vez en mariscador, como pudiera hacerlo tambi\u00e9n en acuicultor<\/span><\/b>. <\/o:p><\/span><\/p>\n

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Policultivo Agua-Suelo. Fuente: It\u2019s a Working Farm<\/font><\/a><\/o:p><\/span><\/p>\n

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He le\u00eddo otra noticia similar de la FAO, respecto <\/span>al cultivo de carpas, tambi\u00e9n muy apreciadas<\/span><\/b> en el sureste asi\u00e1tico, y que pueden vivir en aguas estancadas y algo polucionadas. Hace m\u00e1s tiempo, <\/span>tuve noticia de otros peces que se cultivaban desde anta\u00f1o entre los arrozales encharcados<\/span><\/b> del continente mentado. Obviamente, <\/span>no se trata de ninguna novedad, por cuanto tanto la etnoagricultura, como el conocimiento campesino local<\/span><\/font><\/a>, han hecho uso, de una u otra forma, de este tipo de producciones diversificadas<\/span><\/b>. <\/o:p><\/span><\/p>\n

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Durante los <\/span>\u00faltimos decenios<\/span><\/b>, lamentablemente <\/span>hemos asistido al fomento de los monocultivos<\/span><\/b>. Estos, <\/span>al margen de contaminar el ambiente, comienzan a ser cuestionados, en lo que respecta a sus rendimientos<\/span><\/b>, incluso despu\u00e9s de sembrar cultivares <\/span>gen\u00e9ticamente modificados<\/span><\/b> (ya hablaremos de ello en otro post). Reiteramos una vez m\u00e1s que <\/span>la diversificaci\u00f3n es demandada en econom\u00eda, con vistas a<\/span><\/b> que los empresarios y sus<\/span> compa\u00f1\u00edas no corran muchos riesgos al \u201capostar\u201d por un solo producto<\/span><\/b>.<\/o:p><\/span><\/p>\n

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Acuicultura y cultivos terrestres: Fuente. FAO<\/font><\/a><\/o:p><\/span><\/p>\n

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Obviamente, <\/span>cada ambiente, requerir\u00eda la introducci\u00f3n o reintroducci\u00f3n de animales adaptados a sus caracter\u00edsticas, tras valorarse previamente su rentabilidad<\/span><\/b>. Existen pues <\/span>muchas alternativas posibles<\/span><\/b>. En este caso hablamos de la <\/span>presencia de agua y suelos h\u00eddricos, aunque no resulta<\/span><\/b> estrictamente <\/span>necesario<\/span><\/b>. Bien pudieran utilizarse animales o plantas que no requieran abundancia de este l\u00edquido elemento. Por ejemplo, en las <\/span>Dehesas de la Pen\u00ednsula Ib\u00e9rica<\/span><\/b>, de las que ya os hemos hablado, <\/span>existe una seta<\/span><\/b> (emparentada con las trufas) subterr\u00e1nea (en su totalidad) <\/span>muy apreciada y que crec\u00eda en el suelo de los montes con arbolado m\u00e1s denso<\/span><\/b> (y por lo tanto que puede llegar a ofrecer beneficios nada despreciables si terminamos por entender como fomentar su crecimiento). Hablamos de las <\/span>creadillas de tierra<\/span><\/b>. T<\/span>odo consiste en pensar y planificar, dando alternativas rentables a los campesinos que no causen da\u00f1os ecol\u00f3gicos, diversificando as\u00ed sus producciones y minimizando riesgos<\/span><\/b>. Rescatar el conocimiento campesino, al margen de otras posibilidades, ser\u00eda una gran fuente de inspiraci\u00f3n.  <\/span>Seguiremos hablando de estos asuntos. <\/o:p><\/span><\/p>\n

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Juan Jos\u00e9 Ib\u00e1\u00f1ez    <\/span> <\/span><\/o:p><\/span><\/p>\n

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Researchers Turning Freshwater Farm Ponds Into Crab Farms<\/font><\/a><\/span><\/b><\/o:p><\/span><\/p>\n

by Staff Writers; <\/span>Raleigh<\/span><\/st1:city> <\/span>NC<\/span><\/st1:state><\/st1:place> (SPX) <\/span>Oct 22, 2008<\/span><\/st1:date><\/o:p><\/span><\/p>\n


<\/span>Work by researchers at <\/span>North Carolina<\/span><\/b><\/st1:placename> <\/span><\/b>State<\/span><\/b><\/st1:placetype> <\/span><\/b>University<\/span><\/b><\/st1:placetype><\/st1:place> is leading to a new kind of crab harvest – blue crabs grown and harvested from freshwater ponds<\/span><\/b>,<\/span> <\/span>instead of from the sea. <\/o:p><\/span><\/span><\/p>\n

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With the rapid rate of growth for pond-raised crabs<\/span><\/b>, Eggleston expects that in a given year, a farm could produce two to three harvests<\/span><\/b>, as crabs don’t do well in freshwater during the winter months. Crab lovers shouldn’t worry, researchers say, because the pond-raised crabs look and taste just like their ocean-raised brethren<\/span><\/b>.  <\/span><\/span>North Carolina<\/span><\/span><\/b><\/st1:place><\/st1:state>‘s native blue crab population has been at historic lows since 2000<\/span><\/b>. Dr. Dave Eggleston, director of NC State’s Center for Marine Sciences and Technology (CMAST) and professor of marine, earth and atmospheric sciences, looked at <\/span>various methods for helping the population recover<\/span><\/b>.  <\/span><\/span>He hit upon a solution which not only reduces pressure on existing crab populations, but also benefits farmers<\/span><\/b> <\/span>looking to diversify their crops<\/span><\/b>: <\/span>using irrigation ponds on farms to grow blue crabs<\/span><\/b>. <\/span>\u00abWe started out by catching small crabs in the wild and stocking them into farm ponds loaded with bass and bluegill predators, and were still able to get 12 percent survival,\u00bb Eggleston says. <\/o:p><\/span><\/p>\n

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\u00abSo we teamed with the University of Maryland’s Center of Marine Biotechnology <\/span><\/b>who had the expertise to growth hatchery-reared blue crabs, and stocked these blue crabs in freshwater experimental aquaculture ponds<\/span><\/b> at NC State’s Vernon James Research and <\/span>Extension<\/span><\/st1:placename> <\/span>Center<\/span><\/st1:placetype><\/st1:place> in <\/span>Plymouth<\/span><\/st1:city>, <\/span>N.C.<\/span><\/st1:state><\/st1:place>, where the crabs exhibited some of the highest growth rates on record<\/span><\/b>.\u00bb <\/o:p><\/span><\/p>\n

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Eggleston then noticed that a lot of farmers in <\/span><\/b><\/span>Eastern<\/span><\/b><\/st1:city> <\/span><\/b>N.C.<\/span><\/b><\/st1:state><\/st1:place> were trying to diversify their crop offerings in response to the decline in tobacco demand<\/span><\/b>. \u00abA lot of these farms have irrigation ponds, and we thought if crabs can live in fresh water, this would take some pressure off the coastal crab population and give farmers another crop<\/span><\/b>, by letting their ponds work for them,\u00bb he says. Eggleston and his fellow researchers discovered that crabs can tolerate a salinity level of only .3 parts per thousand, which is about the same level found in coastal tap water<\/span><\/b>. <\/span>They did further work to determine the best set of circumstances for raising crab: population density, food rations, and habitat structure in ponds<\/span><\/b>.<\/o:p><\/span><\/p>\n

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This past July, Eggleston and Ray Harris, NC State director of cooperative extension for Carteret County, had the opportunity for a large-scale test when they stocked a 10-acre lake with 40,000 hatchery-raised crabs, and a smaller pond with 4,000 crabs. <\/span>The crabs will take approximately 105 days to reach maturity, and so far the endeavor looks successful<\/span><\/b>. With the rapid rate of growth for pond-raised crabs,<\/span><\/b> Eggleston expects that in a given year, a farm could produce two to three harvests, <\/span><\/b>as crabs don’t do well in freshwater during the winter months. \u00abIf you look at a 2 1\/2 -acre pond, you could stock it with 50,000 hatchery-raised crabs and expect to harvest around 20 percent, or 10,000 fully grown crabs. <\/span><\/b><\/span>At $3 per crab, that’s $30,000<\/span><\/b> – and multiply that times three. It definitely adds up.\u00bb <\/o:p><\/span><\/p>\n

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Funding for this research was provided by the N.C. Blue Crab Research Program that was established by the N.C. General Assembly and is administered by North Carolina Sea Grant. <\/o:p><\/span><\/p>\n

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<\/span>Related Links<\/o:p><\/span><\/b><\/p>\n

North Carolina State University<\/font><\/span><\/a><\/span><\/o:p><\/span><\/p>\n

Farming Today – Suppliers and Technology<\/font><\/span><\/a><\/span><\/o:p><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Resulta cada vez m\u00e1s habitual leer este tipo de noticias en la prensa cient\u00edfica de EE.UU. Mientas por estos lares hispanos olvidamos la agricultura diversificada de nuestros antepasados, en Estados Unidos la reinventan. Ya os hemos comentado en otros post, como en este, que la agricultura industrial cada vez se encuentra m\u00e1s cuestionada, incluso frente a policultivos bien planificados. No hablamos tan solo del medio ambiente, sino incluso de productividad. En la noticia de Sciencedaily que os mostramos abajo, se muestra como los cient\u00edficos de aquel pa\u00eds, ante la urgencia de los agricultores de Carolina del Norte, por sufrir un\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[599,613,587],"tags":[],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/116593"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=116593"}],"version-history":[{"count":2,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/116593\/revisions"}],"predecessor-version":[{"id":134894,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/116593\/revisions\/134894"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=116593"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=116593"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=116593"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}