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).

中文翻译：

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适用于地中海温室的混合被动冷却和加热系统。小气候和甜椒作物反应


地中海地区技术含量低、无暖气的温室的小气候与当地的室外气候有关，在温暖和寒冷的生长季节通常都超出了大多数园艺作物的最佳范围。在珍珠岩种植袋中种植的代表性夏季移植甜椒作物上，对新型被动冷却（蒸发屏）和加热（充水套筒）混合系统的使用以及内部可移动遮阳/隔热屏的使用进行了评估。该实验在阿尔梅里亚（西班牙东南部）IFAPA La Mojonera 研究中心的两个相同的温室中进行：一个温室配有混合被动式冷却和加热系统，并配有遮阳/隔热屏，另一个温室（参考温室）使用当地常见的温室气候管理实践。蒸发幕与可移动遮阳幕相结合，改善了温室气候，特别是空气蒸气压不足，并增加了作物早期的叶面积指数，从而提高了叶和作物的早期产量。与参考温室作物相比，芽干物质和可销售的果实。此外，在冷生长期间结合使用充水套筒和隔热屏提高了温室空气温度（尤其是夜间）和基质温度。 总体而言，通过改善温暖和寒冷生长期的温室小气候，混合被动冷却/加热系统与遮阳/隔热屏相结合，将夏季移栽甜椒作物的可销售产量提高了 25%，减少了灌溉供水量提高了 8%，灌溉用水效率提高了 20%（包括用于加湿蒸发幕的潜在水量）。