Understanding the relationships between topographic indices and crop yield variability is important for soil manage- ment and crop production in rolling landscape. Two agricultural fields at Alvena and Hepburn, Saskat...Understanding the relationships between topographic indices and crop yield variability is important for soil manage- ment and crop production in rolling landscape. Two agricultural fields at Alvena and Hepburn, Saskatchewan, Canada were selected to examine how topographic indices were related to wheat yield under two topographic and weather conditions in the Canadian prairies. The landscapes of the two sites are classified as hummocky and the dominant soil type is an Aridic Ustoll. The relationships among yield, topography, soil, and weather were analyzed using wheat (Triticum aestivum L.) grain yield from Alvena in 2001 (dry year) and 2004 (wet year) and from Hepburn in 1998 (dry year). Topographic/soil indices included relative elevation, wetness index, upslope length, curvature, soil organic matter, and soil moisture storage before seeding. The results indicated that, in the dry years, the correlation coefficients between upslope length and grain yield were 0.79 for the typical rolling landscape (Alvena) in 2001 and 0.73 for shallow gentle rolling landscape (Hepburn) in 1998. In the wet year (2004), the relationships between yield and topographic/soil attributes were not as strong as in dry years. Therefore, upslope length was the best yield indicator for the two landscapes in dry years, whereas no topographic indices were highly correlated to crop yield in wet years. Those topographic indices seemed useful in identifying the yield variability and delineating the proper management zone.展开更多
The physiological effect of new FA antitranspirant on winter wheat was studied by field trial. The new FA antitranspirant was sprayed at ear filling stage, using the following concentrations： 0.5, 1.0, 1.5 and 2.0 mL...The physiological effect of new FA antitranspirant on winter wheat was studied by field trial. The new FA antitranspirant was sprayed at ear filling stage, using the following concentrations： 0.5, 1.0, 1.5 and 2.0 mL L^-1. The results indicated that new FA antitranspirant increased nitrate reductase activity （NRA）, free proline content, chlorophyll content and water content of leaf, thus drought stress can be mitigated. The new FA antitranspirant increased photosynthesis, enlarged stomatal conductance and reduced transpiration rate, thus led to growth stimulation and water loss reduction. New FA antitranspirant caused an increase of grain yield by 7.2%, under the optimal concentration 1.5 mL L^-1.展开更多
基金Project supported by the National Science and Engineering Research Council (NSERC) of Canada.
文摘Understanding the relationships between topographic indices and crop yield variability is important for soil manage- ment and crop production in rolling landscape. Two agricultural fields at Alvena and Hepburn, Saskatchewan, Canada were selected to examine how topographic indices were related to wheat yield under two topographic and weather conditions in the Canadian prairies. The landscapes of the two sites are classified as hummocky and the dominant soil type is an Aridic Ustoll. The relationships among yield, topography, soil, and weather were analyzed using wheat (Triticum aestivum L.) grain yield from Alvena in 2001 (dry year) and 2004 (wet year) and from Hepburn in 1998 (dry year). Topographic/soil indices included relative elevation, wetness index, upslope length, curvature, soil organic matter, and soil moisture storage before seeding. The results indicated that, in the dry years, the correlation coefficients between upslope length and grain yield were 0.79 for the typical rolling landscape (Alvena) in 2001 and 0.73 for shallow gentle rolling landscape (Hepburn) in 1998. In the wet year (2004), the relationships between yield and topographic/soil attributes were not as strong as in dry years. Therefore, upslope length was the best yield indicator for the two landscapes in dry years, whereas no topographic indices were highly correlated to crop yield in wet years. Those topographic indices seemed useful in identifying the yield variability and delineating the proper management zone.
文摘The physiological effect of new FA antitranspirant on winter wheat was studied by field trial. The new FA antitranspirant was sprayed at ear filling stage, using the following concentrations： 0.5, 1.0, 1.5 and 2.0 mL L^-1. The results indicated that new FA antitranspirant increased nitrate reductase activity （NRA）, free proline content, chlorophyll content and water content of leaf, thus drought stress can be mitigated. The new FA antitranspirant increased photosynthesis, enlarged stomatal conductance and reduced transpiration rate, thus led to growth stimulation and water loss reduction. New FA antitranspirant caused an increase of grain yield by 7.2%, under the optimal concentration 1.5 mL L^-1.
