Hung Kuo-An, Hsu Yi-Wei, Chen Yu-Cheng, Lin Tzu-Ping
Department of Architecture, National Cheng Kung University, 1 University Rd., East Dist., Tainan, 701, Taiwan.
Department of Architecture and Landscape Design, Nanhua University, No. 55, Sec. 1, Nanhua Rd., Dalin Township, Chiayi County, 62249, Taiwan.
Int J Biometeorol. 2023 Jul;67(7):1225-1235. doi: 10.1007/s00484-023-02490-8. Epub 2023 May 13.
High temperatures have become common in cities in Taiwan, and this phenomenon has spread to surrounding agricultural areas. Tainan, a city located in a tropical climate zone with agriculture as its primary development industry, is one of the cities considerably affected by the high temperature. High temperatures can reduce crop yields and even cause plant death, especially for vulnerable high-value crops, which are severely to microclimate conditions. Asparagus is a high-value crop that has long been cultivated in the Jiangjun District of Tainan. Recently, asparagus has been planted in greenhouses to protect against pests and natural disasters. However, the greenhouses can overheat. To identify the optimal growth environment for asparagus, this study applies vertical monitoring to record the temperature in the greenhouse and the soil moisture content of a control (canal irrigation) and an experimental (drip irrigation) group. When the surface layer of the soil exceeds 33°C, the tender stems of asparagus bloom readily, reducing its commercial value. Therefore, drip irrigation was conducted with cool water (26°C) to reduce soil temperature in summer and warm water (28°C) to increase soil temperature in winter. The study also recorded the growth of asparagus using daily yields measured by farmers during weighing and packing to understand the benefits of controlling the greenhouse microclimate. This study reports a correlation of 0.85 between asparagus yield and temperature and a correlation of 0.86 between asparagus yield and soil moisture content. The use of a drip irrigation system with a water temperature adjustment function not only saves up to 50% of water but also resulted in an average yield increase of 10% through maintaining stable soil moisture content and temperature. Therefore, the findings of this study can be applied to asparagus yields affected by high temperature and can solve the problems of poor quality in summer and low yield in winter.
高温在台湾城市已很常见，且这一现象已蔓延至周边农业地区。台南是位于热带气候区、以农业为主要发展产业的城市，是受高温影响较大的城市之一。高温会降低作物产量，甚至导致植物死亡，尤其是对于易受影响的高价值作物，它们对小气候条件极为敏感。芦笋是一种长期在台南将军区种植的高价值作物。近年来，芦笋被种植在温室中以抵御病虫害和自然灾害。然而，温室可能会过热。为确定芦笋的最佳生长环境，本研究采用垂直监测来记录温室温度以及对照组（渠道灌溉）和实验组（滴灌）的土壤湿度。当土壤表层温度超过33°C时，芦笋的嫩茎容易开花，从而降低其商业价值。因此，夏季用冷水（26°C）进行滴灌以降低土壤温度，冬季用温水（28°C）进行滴灌以提高土壤温度。该研究还通过农民在称重和包装时测量的日产量记录芦笋的生长情况，以了解控制温室小气候的益处。本研究报告称芦笋产量与温度的相关性为0.85，芦笋产量与土壤湿度的相关性为0.86。使用具有水温调节功能的滴灌系统不仅可节水达50%，还通过保持稳定的土壤湿度和温度使平均产量提高了10%。因此，本研究的结果可应用于受高温影响的芦笋产量，并可解决夏季品质差和冬季产量低的问题。
