Modeling the Emergence of Winter Wheat in Response to Soil Temperature, Water Potential, and Planting Depth

2014 ◽  
pp. 761-775
2019 ◽  
Vol 70 (6) ◽  
pp. 1280-1289 ◽  
Author(s):  
Qiuyan Yan ◽  
Fei Dong ◽  
Junhui Li ◽  
Zengqiang Duan ◽  
Feng Yang ◽  
...  

2002 ◽  
Vol 12 (3) ◽  
pp. 181-191 ◽  
Author(s):  
Amanda J. Ellery

Changes in embryo dormancy of capeweed [Arctotheca calendula (L.) Levyns.] seeds in response to temperature were investigated to determine the nature of seasonal dormancy cycles. Primary embryo dormancy persisted for 2–3 months after seed collection and was then rapidly relieved when seeds were maintained at temperatures simulating summer soil surface temperatures. Embryo dormancy was also rapidly relieved in seeds maintained at constant temperatures, indicating that a daily temperature fluctuation was not necessary for the relief of embryo dormancy in capeweed. Dormancy relief was maximal at 40°C. Secondary dormancy was induced when seeds were maintained at low temperatures and a water potential of –1.5 MPa, suggesting that the onset of winter may postpone germination until a subsequent autumn. These results indicate that the dormancy cycles observed in capeweed seeds maintained on the soil surface are probably driven by seasonal changes in soil temperature.


2017 ◽  
Vol 155 (9) ◽  
pp. 1394-1406 ◽  
Author(s):  
X. M. MAO ◽  
W. W. ZHONG ◽  
X. Y. WANG ◽  
X. B. ZHOU

SUMMARYThe production of winter wheat (Triticum aestivum L.) is affected by crop population structures and field microclimates. This 3-year study assessed the effect of different precision planting patterns and irrigation conditions on relative humidity (RH), air and soil temperature within the canopy, intercepted photosynthetically active radiation (iPAR), evapotranspiration (ET), water productivity (WP) and grain yields. Field experiments were conducted from 2011 to 2014 on a two-factor split-plot design with three replicates. The experiments involved three precision planting patterns (single row, alternating single and twin rows [hereafter ‘single–twin’] and twin row) and three irrigation treatments (0 mm (I0), 90 mm (I90) and 180 mm (I180)). Planting patterns and irrigation treatments exerted a significant effect on RH, air and soil temperature, iPAR, ET, WP and grain yield. The lowest RH and iPAR levels were detected in the single row pattern. When the irrigation treatment was identical, the highest soil and air temperatures were detected in the single row pattern, followed by the single–twin row and twin row patterns. Compared with the single row, the single–twin and twin row patterns increased ET by 0·3 and 1·4, WP by 4·7 and 5·7% and yields by 6·0 and 7·9%, respectively. Compared with I0, the I90 and I180 irrigation treatments increased ET by 0·3 and 1·4%, and WP by 4·7 and 5·7%, respectively. The grain yields of the twin row pattern were 5·8 and 1·7% higher than those of the single row and single–twin row patterns, respectively. Compared with I0, I90 increased yield by 19·3%. The twin row pattern improved crop structure and farmland microclimate by increasing RH and iPAR, and reducing soil and air temperatures, thus increasing grain yield. These results indicated that a twin row pattern effectively improved grain yield at I0. On the basis of iPAR, WP and grain yield, it was concluded that a twin row pattern combined with an I90 irrigation treatment provided optimal cropping conditions for the North China plain.


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