[CH4 emission features of leading super-rice varieties and their relationships with the varieties growth characteristics in Yangtze Delta of China].

A pot experiment was conducted to study the CH4 emission features of fourteen leading super-rice varieties (six Japonica rice varieties and eight Indica hybrid rice varieties) and their relationships with the varieties growth characteristics in Yangtze Delta. Two distinct peaks of CH4 emission were detected during the entire growth period of the varieties, one peak occurred at full-tillering stage, and the other appeared at booting stage. The average total CH4 emission of Japonica rice varieties was 37.

[Effects of nighttime warming on winter wheat root growth and soil nutrient availability].

Climate warming has an obvious asymmetry between day and night, with a greater increment of air temperature at nighttime than at daytime. By adopting passive nighttime warming (PNW) system, a two-year field experiment of nighttime warming was conducted in the main production areas of winter wheat in China (Shijiazhuang of Hebei Province, Xuzhou of Jiangsu Province, Xuchang of Henan Province, and Zhenjiang of Jiangsu Province) in 2009 and 2010, with the responses of soil pH and available nutrient contents during the whole growth periods and of wheat root characteristics at heading stage determined. As compared with the control (no nighttime warming), nighttime warming decreased the soil pH and available nutrient contents significantly, and increased the root dry mass and root/shoot ratio to a certain extent.

[Effects of asymmetric warming on the growth characteristics and yield components of winter wheat under free air temperature increased].

In 2007-2009, a field warming experiment was performed in Nanjing of Jiangsu Province, China to investigate the effects of asymmetric warming (all-day warming, AW; daytime warming from 6:00 to 18:00, DW; and nighttime warming from 18:00 to 6:00, NW) on the growth and development of winter wheat under free air temperature increase (FATI). Asymmetric warming increased the effective tillers and decreased the ineffective tillers. In CK plot, the ineffective tillers were 2.

[Passive nighttime warming (PNW) system, its design and warming effect].

Based on the technique of passive nighttime warming (PNW), a convenient and energy-saving PNW facility was designed for a rice-wheat cropping system in Danyang, Jiangsu Province. The facility could guarantee 15.75 m2 effective sampling area, with a homogeneous amplitude of increased temperature, and making the nighttime canopy temperature during whole rice growth season increased averagely by 1.

[Temperature differences of air-rice plant under different irrigated water depths at spiking stage].

With rice cultivars Yangdao 6, Yangjing 9538 and Wuxiangjing 14 as test materials, field experiment was conducted to study the effects of 3 irrigated water depths (0 cm, 2-4 cm, and > 10 cm) on the temperature of different parts of rice plant at spiking stage. The results showed that from 10:30 to 15:00 on sunny days, irrigated water depth on paddy field had significant effects on the temperature of field surface, middle part of rice plant, and rice spike. The higher the water depth on field surface, the lower the temperature of rice plant and rice spike.