Changing Characteristics of Major Ecological Factor in Semi- underground Solar-greenhouse at Shouguang, Shandong Province
YU Jun-hui1, DONG Xu-bing1, WEI Jia-peng2, AI Xi-zhen1*
1State Key Laboratory of Crop Biology, Ministry of Agriculture, Key Laboratory of Horticultural Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian 271018, Shandong, China; 2Seedlings Limited Company of New Century in Shouguang City, Shouguang 262702, Shandong, China
Abstract：Major ecological factors in semi-underground and ground solar-greenhouse at Shouguang region were investigated from Sep 2009 to May 2010. The results showed that the air temperature（Ta）in day and night changes from 14.8 ℃ to 40.6 ℃, and soil temperature（Ts）was 19.0-25.0 ℃. Ta and Ts were the lowest in Jan and the highest in May. The relative humidity（RH）changed from 42.6 % to 97.7 %. Again it was the higher in Jan and Mar, the lowest in May. Ta changed with the similar rule to Ts in day and night. Ta came to the lowest at 5：30-7：30, and to the highest at 12：00-13：30. The lowest and highest value of Ts appeared at 8：30-10：30 and 17：30-20：00, respectively. RH in day and night changed contrary to Ta, its lowest value appeared at 12：00-15：00, and the highest appeared at 7：00- 9：00. The photon flux density（PFD）changed from 211.0 μmolm-2?s-1 to 1 304.7 μmolm-2?s-1. The CO2 concentration was 207-1 219 μl?L-1. The PFD increased in the morning, and decreased in the afternoon, but the CO2 concentration was changed oppositely in clear day. Their peaks or valleys appeared at 11：00-14：00. Compared with the ground solar-greenhouse, the semi-underground one showed higher Ta, Ts and RH and almost the same PFD and CO2. During the day, time with higher than 35 ℃Ta and higher than 90 % RH was longer and time with Ta lower than 20 ℃ and RH lower than 70 % was shorter.