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Accueil du site → Doctorat → Chine → 2014 → Climate Sensitivity and Adaptation Flexibility for Five Dominant Crops in Agro-pastoral Ecotone in Inner Mongolia

Université de l’agriculture de Chine (2014)

Climate Sensitivity and Adaptation Flexibility for Five Dominant Crops in Agro-pastoral Ecotone in Inner Mongolia

杨宁;

Titre : Climate Sensitivity and Adaptation Flexibility for Five Dominant Crops in Agro-pastoral Ecotone in Inner Mongolia

Auteur : 杨宁;

Grade : Doctoral Dissertation 2014

Université : Université de l’agriculture de Chine

Résumé
Agro-pastoral ecotone is very sensitive to climate change. The warmer and drier climate change would have a profound effect on the rain-fed crops. The research on the response of the main crops to the climate change and the reasonable measures accordingly are crucial important to the sustainable development of agricultural areas. To clarify the climate sensitivity and adaptation flexibility of growing seasons for main crops, five regional representative crops, including two cereal crops (spring wheat and oats), two oil-bearing crops (rapeseed and sunflower), and Starchy crops (potato) were selected for the different sowing date experiments conducted from2009to2013at Wuchuan Scientific Observing and Experimental Station of Agro-Environment, Inner Mongolia.The main conclusions are as follows :(1) The accumulated temperature required completing a certain growth stage and the whole growth period, and the physiological development time (the growing days under the optimum temperature conditions) were determined in this article. The results showed that:spring wheat needs95.3physiological development days and1941℃-d to complete the whole growing season ; oats needs74.6physiological development days and1664℃-d to complete the whole growing season ; rapeseed needs103.9physiological development days and2180℃-d to complete the whole growing season ; sunflower needs112.9physiological development days and2180℃-d to complete the whole growing season ; potato needs97.7physiological development days and2202℃·d to complete the whole growing season.(2) The relationships between crop growth and development of different organs and the heat time (accumulated temperature) were discussed. The relationships between the dry matter distribution ratio of spring wheat spike and oats spike and the accumulated temperature were:y=50.9661n(x)-340.17, R2=0.7581, y=1.7614e00019x, R2=0.5077, respectively. The relationships between the dry matter distribution ratio of rapeseed pods and sunflower seeds and the accumulated temperature were : y=1.7575e0002x, R2=0.5638and y=0.1922e00029x, R2=0.7817, respectively. The relationship between the dry matter distribution ratio of potato tubers and the accumulated temperature was : y=3.4985e00019x,R2=0.6794.(3) The yields of spring wheat, oats, rapeseed, sunflower, and potato for different years and different sowing dates were1999±849kg/ha,2925±954kg/ha,2189±526kg/ha,2175±325kg/ha, and19440±2539kg/ha, respectively. After Mid-May sowing, the yield and1000kernel weight of spring wheat and sunflower decreased significantly. There was no significant relationship between the rapeseed yield and the sowing date, which was the same as the oats yield, while with delayed sowing date, the1000kernel weight decreased significantly. There was no significant difference between different sowing dates for potato, while the ratio of commercial potato got decreased with the delayed sowing date. Among these five crops, water utilization efficiency and heat utilization efficiency of oats and potato were higher than other three crops.(4) Combining the meteorological data from1960to2013with the results obtained from this study, the flexible sowing ranges of spring wheat, oats, rapeseed, sunflower and potato were determined. Compared with the1960s, during the past ten years, the average of suitable sowing interval of spring wheat, oats, rapeseed, sunflowers and potatoes increased by13,13,16,25and22days, respectivelyIn conclusion, under the background of climate warming, it showed a warmer and drier trend in northern China, which resulted in an increasing trend for the flexible sowing range for spring crops at northern Agro-pastoral ecotone. The yield and resource use efficiency of different crops were different due to different climate conditions. It is one of the important measures to realize the agricultural sustainable development to choose the high stability species like oats and potato and to sow during a proper range

Mots clés : sowing time; physiological development time (PDT); flexible sowing windows;

Présentation (CNKI)

Page publiée le 19 novembre 2017