长江流域不同种植区气候因子对冬油菜产量的影响

气象因子对长江流域油菜（Brassica napus L.）主产区影响很大。为明确长江流域影响油菜生长的关键气象因子,基于长江流域259个气象站1961-2015年的气象数据及1437个田间试验冬油菜产量数据,分析5个不同区域（长江上游低海拔区、长江上游高海拔区、长江中游二熟区、长江中游三熟区和长江下游）冬油菜生育期内气候因子的时空分布特征,结合产量数据分析不同种植区油菜产量的气候限制因子。结果表明：长江流域冬油菜生育期 内平均气温为13.2℃,≥0℃积温为3620℃,昼夜温差7.8℃,总日照时数984h,太阳辐射量为2631 MJ·m-2。油菜生育期内热量资源呈现增加的趋势,平均气温每10年升高0.37℃,而昼夜温差每10年缩小0.21℃;而日照资源则逐年降低,每10年日照时数降低45h。油菜全生育期总降水量平均为680 mm,且呈现逐年增加的趋势。长江流域气象因 子与油菜产量的关系主要表现为：平均气温和≥0℃积温与产量呈现负相关关系,其中长江中游二熟区生育前期（9 月-11月）和长江中游三熟区生育后期（3月-5月）平均气温每增加0.1℃,油菜分别减产53和40 kg·hm-2;昼夜温差大有利于油菜增产,其中长江上游低海拔区后期昼夜温差每增加0.1℃,产量增幅为39 kg·hm-2;降水量与产量主要呈现负相关关系,尤其是后期降水量每增加10 mm,油菜减产约12～39 kg·hm-2。从整个生育期来看,长江上游（低海拔区、高海拔区）主要影响油菜产量的气象因子为昼夜温差、降水量和日照时数;长江中游二熟区主要受气温、积温、降水量和太阳辐射的影响;长江中游三熟区的限制因子为气温和积温;而长江下游则受到降水量、日照时数和太阳辐射的影响。

Climate impacts on yield of winter oilseed rape in different growth regions of the Yangtze River Basin

Meteorological factors strongly affected oil rape (Brassica napus L.) growth in the Yangtze River Ba? sin, the most important rapeseed growth area in China. To better understand the key factors in different regions of the basin area, spatial and temporal distribution features of climatic factors in 5 different regions were analyzed based on 1961-2015 data from 259 meteorological stations and 1437 field experiments. Results showed that climate condition during the growing period of winter rapeseed in the Basin was on the average of 13.2 °C, 3620 °C of accu? mulated temperature above 0 °C, 7.8 °C of diurnal temperature variation, 984 h of sunshine duration, and 2631 MJ· m-2 of solar radiation. Heat resources increased during rapeseed growth period, with an average increase of 0.37 °C in every decade, and diurnal temperature variation decrease by 0.21 °C during every decade. Sunshine duration de? creased in each year with 45 h less in every decade. Total precipitation in whole growth period was 680 mm on aver? age and increased in each year. The relationship between meteorological factors and rapeseed yield were analyzed. Negative correlation was found between different average temperature and accumulated temperature above zero. Ev? ery 0.1 °C increase of average temperature led to 53 kg·hm-2 yield loss in double cropping system areas of the mid? 2019,41（6）：894-903 dle reaches from Sept. to Nov., and 40 kg·hm-2 yield loss in triple cropping system areas of the middle reaches from the next Mar. to May. On the contrary, every 0.1 °C increase of diurnal temperature variation led to yield increase of 39 kg·hm-2 especially in the low altitude areas in upper reaches. There was negative correlation between yield and precipitation. Especially in late stage, yield decreased 12-39 kg·hm-2 when late precipitation increased by 10 mm. Considering the 4 regions in the whole period, yield were affected mainly by diurnal temperature variation, precipita? tion and sunshine durations in low and high altitude areas in upper reaches; by temperature, accumulated tempera? ture, precipitation and solar radiation on the middle reaches; and by precipitation, sunshine durations and solar radi? ation on the lower reaches.