Nueva especie de microalga y su aplicación para consumo animal, humano y en la obtención de carotenoides

Número de publicación: ES2259548 A1 (01.10.2006) También publicado como: ES2259548 B1 (01.10.2007) Número de Solicitud: Consulta de Expedientes OEPM (C.E.O.)P200500374 (18.02.2005)Una nueva cepa de Scenedesmus ha sido aislada en la estación experimental "Las Palmerillas-CAJAMAR", siendo identificada como "microorganismo no previamente registrado" por la Universidad de Gottinghem, y depositada en la Culture Collection of Alagae and Protozoa (CCAP) como Scenedesmus almeriensis. La nueva cepa puede ser utilizada para consumo animal y/o humano, y produce elevadas cantidades de carotenoides, especialmente luteína y betacaroteno. Scenedesmus almeriensis crece adecuadamente en un amplio rango de temperaturas de 10°C a 40°C, a un pH de 7.0 a 9.5, y es tolerante a elevadas concentraciones de cobre, de hasta 1 mg/L. La cepa microalgal, cultivada en un fotobiorreactor de 4000 L en el que el cultivo se impulsa mecánicamente, produce luteína en una cantidad de al menos 4 mg por gramo de materia seca. Esta cepa es muy adecuada para la producción de carotenoides de aplicación en el tratamiento de desordenes de la macular ocular.Universidad de Almerí

Reuse of rockwool slabs and perlite grow-bags in a low-cost greenhouse: Substrates’ physical properties and crop production

Multiannual inert substrates, especially perlite grow-bags and rockwool slabs, are widely used over several cropping seasons in low-cost plastic greenhouses in mild winter climates, such as the Mediterranean coast of South-east Spain. This work analyses how the physical properties of rockwool slabs and perlite grow-bags change with time and use, as well as studying the response of sweet pepper and melon crops grown in new and reused perlite grow-bags and rockwool slabs. The main aims are to reduce expenditure and the environmental impacts of soilless crops grown in low-cost greenhouse areas. The main physical properties, including air capacity and easily available water, of reused rockwool slabs remained quite steady over three cropping years, and no negative effects were found in the fertigation, growth and productivity of sweet pepper and melon crops when grown in reused slabs, compared to new ones. The main physical properties of 5-year-old reused perlite grow-bags also remained steady and had no negative effect on the fertigation, growth and productivity of sweet pepper and melon crops. Therefore, the life-span of rockwool slabs and perlite grow-bags can be extended to 3 or 5 cropping years, respectively, for both crops

Effects of gravel mulch on surface energy balance and soil thermal regime in an unheated plastic greenhouse

This work analyses how a mulch layer of mostly gravel particles affected the soil thermal dynamics in an unheated plastic greenhouse in a Mediterranean area (South-East Spain), where suboptimal regimes of soil temperature usually prevail in winter crop cycles. Soil temperature and heat flux profiles were measured in two soil types: (i) a 0.1-m thick gravel mulch (GM) placed at the top of a 0.30-m layer of imported loamy soil and (ii) the latter without gravel mulch (NM). These measurements were conducted during a winter period (14–28 January) when the dominant source of energy in the soil root-zone was the heat from deeper soil layers. The higher albedo of the GM and its higher long-wave radiation losses reduced substantially the daily net radiation at the mulch surface by ca. 77% with respect to NM. However, the soil root-zone maintained warmer under the GM than with NM in a period when soil temperatures are usually below the optimum. This was mainly caused by the insulating property of the mulch, which acted as heat barrier and increased the resistance to heat transmission from deep soil horizons towards the surface. This passive heating of the soil root-zone by using a gravel mulch was later confirmed in a summer–winter cycle of sweet pepper grown in an unheated plastic greenhouse. The gravel mulch also reduced the soil evaporation and increased the reflected short-wave radiation towards the plants, but the air temperature above the mulch fluctuated more strongly than in the absence of the mulch

How plastic mulches affect the thermal and radiative microclimate in an unheated low-cost greenhouse

Suboptimal regimes of air and soil temperature usually occur under unheated greenhouses during winter crop cycles. This work analyses the effects of three soil surface treatments (no plastic mulch, NM; transparent mulch, TM, and black mulch, BM) on the air-soil heat exchanges and the resulting soil and aerial microclimate. Experiments were conducted in unheated greenhouse compartments located in an area of mild winter climate (South-East Spain) during autumn and winter periods. In all treatments, the soil consisted of an artificial layer of 0.10 m gravel-sand material placed above a 0.3 m layer of imported loamy soil. When vents were closed, soil heat flux, ground net radiation and both air and root-zone temperature were higher in BM than in TM, while NM presented intermediate performances between BM and TM. When vents were open, heat storage and soil warming were substantially reduced with respect to unventilated conditions. This reduction was greater in BM, and so the advantages of BM with respect to the other treatments were only marginal under ventilated conditions. The main conclusions were: (i) The combination of black mulch + greenhouse appears to be a simple and low-cost passive heating system that can be recommended for the early stages of crop cycles starting at the end of autumn or in winter, when canopy leaf area index is small and most of the soil surface is free of vegetation; and (ii) ventilation had a negative effect on the benefits of mulching, implying that greenhouse ventilation management should reflect a compromise between maximizing greenhouse heat storage and fulfilling ventilation requirements for suitable crop growth

How mulching and canopy architecture interact in trapping solar radiation inside a Mediterranean greenhouse

This work evaluates roles and interactions of ground albedo (ag) and canopy architecture in capturing solar radiation inside Mediterranean greenhouses. Both incident and reflected solar radiation were measured over the ground surface and the greenhouse roof cover during a series of greenhouse experiments where common types of mulch and crop architecture were combined. In the experiments without crop around winter, changes in the daily mean ag from 0.06 to 0.38 induced changes in the greenhouse cover albedo (ac), which ranged from about 0.20 to 0.42. In measurements carried out around winter, both the ag and ac decreased when the ratio of the outdoor diffuse-to-solar radiation increased, independently of the ground surface, indicating that a higher percentage of solar radiation was trapped by the greenhouse under diffuse than under sunny conditions. In crops grown horizontally (not vertically trained), the effect of ground mulching over ag vanishes progressively with the increase in leaf area of the crops, resulting in an asymptotic trend of ag close to 0.23 at full ground covering, independently of the mulch type. In crops grown with high-wire production systems (plants grown in separated rows with the canopy distributed vertically up to 1.5–4.0 m high), asymptotic ag values were also reached but they were lower and dependent on the mulch type and the canopy architecture (0.08 for with black mulch and 0.12 to 0.19 with a gravel mulch). Then, crops with high-wire production systems, common in greenhouses, presented a higher efficiency in trapping solar radiation inside greenhouses. A model, which predicts fairly well the ac from the knowledge of ag and the cover shortwave reflectance, was proposed and used

Hybrid passive cooling and heating system for Mediterranean greenhouses. Microclimate and sweet pepper crop response

The microclimate of low-tech, unheated greenhouses in Mediterranean areas, associated with the local outdoor climate, is often outside the optimal range for most horticultural crops during both the warm and cold growing season. The use of a new hybrid system of passive cooling (evaporative screens) and heating (water-filled sleeves), in combination with an internal movable shading/thermal screen, was evaluated on a representative summer transplanted sweet pepper crop grown in perlite growing bags. The experiment was carried out in two identical greenhouses at the IFAPA La Mojonera research center in Almeria (SE Spain): one greenhouse with the hybrid passive system of cooling and heating, in combination with a shading/thermal screen, and another (reference greenhouse) using common local greenhouse climate management practices. Evaporative screens, in combination with a movable shading screen, improved the greenhouse climate, in particular the air vapour pressure deficit, and increased the leaf area index in the early stages of the crop, which, in turn, increased the early production of leaf and shoot dry matter and marketable fruit, compared to the reference greenhouse crop. In addition, the combined use of water-filled sleeves and thermal screen during the cold growth period increased greenhouse air temperatures, especially at night, and substrate temperatures. Overall, by improving the greenhouse microclimate during the warm and cold growth periods, the hybrid passive cooling/heating system, in combination with the shading/thermal screen, increased the marketable yield of a summer transplanted sweet pepper crop by 25 %, reduced the irrigation water supply by 8 %, and improved the irrigation water use efficiency by 20 % (including the potential water used to humidify the evaporative screens)

Sistemas pasivos de calefacción en invernaderos mediterráneos.

El libro es un compendio de las técnicas de calefacción pasiva de interés para los invernaderos de clima mediterráneo. Se analizan seis técnicas: materiales de cubierta, acolchados, dobles techos, pantallas térmicas, mangas de agua y “tunelillos”, nombre popular con el que se conoce el pequeño túnel que cubre las hileras de plantas en las primeras fases de cultivo