不同降水年型下播期对晋南旱地小麦产量和水分利用率的影响

根据近54年来山西省临汾市逐日降水量,将7个试验年份分为丰水年型、平水年型和枯水年型,研究了不同年型不同播期对旱地小麦关键生育期持续时间、降水、积温、日照时数、小麦产量及籽粒水分利用效率的影响,并进行相关、多元回归和通径分析,为旱地小麦稳产高产提供理论依据和技术支撑。结果表明,播期对小麦生育期持续时间的影响主要表现在苗期、分蘖期和起身拔节期,而对抽穗期和成熟期影响最多仅相差1 d。旱地小麦全生育期持续时间与积温显著正相关。降水年型显著影响旱地小麦产量及其构成因素,相同降水年型下降水分布不同小麦产量也有较大差异,丰水年型旱地小麦产量较平水年型和枯水年型分别提高100.0%和135.9%。籽粒水分利用率为丰水年型枯水年型平水年型,丰水年型和枯水年型下,籽粒水分利用率随播期推迟而升高,平水年型下,籽粒水分利用率随播期推迟先升高后降低。在拔节—抽穗期,小麦产量与积温显著负相关,与日照时数极显著负相关,与降水量极显著正相关;在抽穗—成熟期,产量与积温、日照时数均呈极显著正相关。年降水量及其分布是影响旱地小麦稳产高产的关键,丰水年型适播期在10月4日左右,产量构成因素协调,可获得高产,同时生育期耗水量最少,水分利用率较高;平水年型和枯水年型适播期应在9月28日左右,产量最高,水分利用率也较高。随播期推迟,应适当加大播量。

Impact of sowing date on yield and water use efficiency of wheat in different precipitation years in dryland of South Shanxi

Sowing date affects individual development before winter, population quality and yield of wheat. Planting area of wheat in dryland of South Shanxi accounts for 60% total area of the province. The precipitation in the area plays an important role in ensuring agriculture production and food security in Shanxi Province. Under global warming conditions, research on proper sowing date of wheat in Shanxi Province is significant for sustainable development of agriculture. Seven years from 2008 to 2015 were divided into three kinds of precipitation year types-wet precipitation year (2012, 2014 and 2015, precipitation of 527.8-597.2 mm), normal precipitation year (2011, 2013, precipitation of 450.7-483.3 mm) and dry precipitation year (2009, 2010, precipitation of 293.4-385.4 mm), based on the average annual precipitation of Linfen in Shanxi Province in the past 54 years. Precipitation, accumulated temperature, sunshine duration during wheat growth season, as well as wheat growth duration, yield and water use efficiency (WUE) under three sowing dates (Sep. 20, 30 and Oct. 5 in 2008-2009; Sep. 22, 28, and Oct. 4 in 2009-2015) were analyzed to provide a theoretical basis and technological support for high and stable yield production of dryland wheat. The relationship between yield, yield components, WUE and meteorological factors were also analyzed by correlation, multiple regression and path analysis. Results showed that sowing dates significantly affected seedling, tillering and jointing period duration, while no significant effect was observed at booting and maturing stages. There was a significantly positive relationship between wheat growth duration and accumulated temperature. Precipitation year and precipitation distribution in wheat growth season affected wheat yield and yield components significantly. Yield in wet precipitation years were 100.0% and 135.9% higher than those in normal and dry precipitation years, respectively. For different precipitation year types, WUE of grain were wet precipitation year > dry precipitation year > normal precipitation year. WUE of grain were increased with the delay of sowing date in wet and dry precipitation years, but was increased when sowed before Sep. 28 and then decreased in the normal precipitation year. From jointing to heading stage, wheat yield was negatively related with accumulated temperature and sunshine duration, positively related with precipitation. From heading to maturing stage, it positively correlated with accumulated temperature and sunshine duration. There was a positive relationship between yield, yield components and water consumption, but no significant relationship between WUE and meteorological factors and yield components. Annual precipitation and its distribution were the key factors determining high and stable wheat yield in dryland. In wet years, Oct. 4 was a suitable sowing date, which was beneficial for coordinative yield components, high yield and WUE, and low water consumption of wheat. In normal and dry years, Sep. 28 was more suitable for higher yield and WUE of wheat.