Impact Of Climate Change On Climate Suitability Of Winter Wheat In Southern Hebei Province

Winter wheat area in Southern Hebei province (abbr. as Ji Nan) belongs toHuang-Huai winter wheat area, planting winter wheat in7.3×105hm2explaining about32%of planting area of Winter Wheat in Hebei province for normal year. Change ofclimate resources makes increasingly instability of winter wheat production. The changesof climate suitability have positive or negative effect on winter wheat production andcause its yield fluctuation. In this paper, on the basis of previous research results,considering the influence of cloudiness on photosynthetic active radiation and antecedentprecipitation on crop growth, the sunshine suitability model and precipitation suitabilitymodel were established. Accumulated temperature suitability model was also establishedreferring to temperature suitability model. The above models reflected influence onwinter wheat growth and development for changes of light, temperature and rainfall.For providing some basis for the appropriate adjustment of cropping system and cropdistribution, introduction and breeding crop varieties, reasonable arrangement ofagricultural structure and establishing scientific investment plan, based on meteorologicalobservation data of4representative stations, winter wheat yield and diseases and pestdata, the characteristics of climatic change, freezing-injury and climatic suitability wereanalyzed for providing some basis on winter wheat production by using moving-averagemethod, wavelet analysis and Mann-Kendall test. The main results are as follows:1. During1962to2011, there was no obvious changes in rainfall. Mean annualtemperature had a markable rising trend and the annual sunshine hours had a markabledeclining trend. Number of annual dry-hot wind day existing remarkable15-20and5-10year’s periodic variation had a notably decreasing trend and it was in an obviouslyless-than-normal period during2013-2020.The wind speed at14:00, which closely relateto the hazard, declined conspciously, and a climatic mutuation point was found at near1982, which palyed an important role in creating dry-hot wind.All grades dry-hot windhazard was decresing, which was benifical to winter wheat filling.freezing injury inoverwintering would tend to occour lightly and freezing injury caused by late frost wouldtend to occour heavly.2. The temperature suitability of winter wheat from high to low was in order of:sowing-overwintering stage, jointing-flowering stage, overwintering stage, reviving- jointing stage, flowering-maturity stage. The temperature suitability degree and thetemperature suitability variation coefficient was undulation inversely in the differentgrowth and development stages. The temperature suitability with remarkable18-25year’s periodic variation was in an obviously less-than-normal period during2013-2020.As regarded to temperature, agrometeorlogical disaster such as freezing injury anddry-hot wind hazard would tend to occour lightly and it was benifical to winter wheatgrowth and development.3．The precipitation suitability of winter wheat from high to low was in order of:sowing-overwintering stage, flowering-maturity stage, overwintering stage, reviving-jointing stage, jointing-flowering stage. Comparatively speaking, the precipitationsuitability of jointing-flowering stage was the lowest, but its coefficnt of variation wasthe biggest and natural precipitation did not meet the need of winter wheat growth anddevelopment. The precipitation suitability of sowing-overwintering stage was the highest,but its coefficnt of variation was the lowest and natural precipitation was optimum forwinter wheat growth and development.4．The sunshine suitability of winter wheat from high to low was consistent withdevelopmental process form sowing to maturity. The lowest was sowing-overwinteringstage and the highest was flowering-maturity stage. Coefficnt of variation ofoverwintering was the largest and jointing-flowering stage was the lowest.it indicted thatthe sunshine conditions helped to filling and maturing. The sunshine suitability ofdifferent stage had three or more periodic variation including stabley remarkable12-15and10-15year’s stable periodic variation in different growing phases during1962to2011.Small scale periodic variation were not obvious, while alternate features exist.5. In the nineteen eighties, while climate warming, powdery mildew, Fusarium headblight, sheath blight was aggravated. Wheat midge occurrence grade was significantlynegative correlation with the precipitation suitability of jointing-flowering stage，theprecipitation suitability of flowering-maturity stage， the temperature suitability ofoverwintering，the temperature suitability of reviving-jointing stage and the sunshinesuitability of reviving-jointing stage. Aphid occurrence grade was significantly negativecorrelation with the sunshine suitability of flowering-maturity stage. Wheat red miteoccurrence grade was significantly negative correlation with the precipitation suitabilityof reviving-jointing stage and flowering-maturity stage, the temperature suitability ofoverwintering. Aphid occurrence grade was significantly positive correlation with theprecipitation suitability of jointing-flowering stage, the temperature suitability offlowering-maturity stage and the temperature suitability of reviving-jointing stage.6．The precipitation suitability in the whole growth period of winter wheatsuitability, which was great variation between years, was the lowest. Respond to theimpact of precipitation on winter wheat production, it was necessary to improve theefficiency of natural rainfall and irrigation water by biological water-saving technologyand agriculture infrastructure construction. Meanwhile, it was important that varietiesimproving, cultivation management, construction of plant diseases and insect pestsprevention and control system.