灌溉和施氮方式对甘肃陇中黄土高原春小麦产量和土壤含水量与有效氮含量的影响

旨在研究影响小麦产量的最佳灌溉与施氮方式组合。以‘定西42号’春小麦为材料,采用水氮互作的方法,设4种灌溉量（单位面积水深50 mm、100 mm、150 mm、200 mm）和3种施肥方式（拔节期施纯氮肥40 kg/hm ²、开花期施纯氮肥40 kg/hm ²、拔节期和开花期施纯氮肥40 kg/hm ²和50 kg/hm ²）。（1）灌溉量150 mm与开花期施氮肥40 kg/hm ²处理时,小麦产量都最高。（2）灌溉量150 mm时各个土层含水量最高,不同施氮处理,各个土层含水量高低顺序为分蘖期<开花期<拔节期。（3）小麦植株耗水量随灌溉量增加而增加、水分利用效率随灌溉量增加而减少。（4）分蘖期灌溉量150 mm时各个土层硝态氮含量最高;拔节期,0~10 cm土层铵态氮和硝态氮含量最高;开花期,灌溉量150 mm和追施纯氮肥40 kg/hm ²时各个土层硝态氮和铵态氮含量最高。灌溉量150 mm和开花期施纯氮肥40 kg/hm ²方式搭配,对甘肃陇中黄土高原春小麦产量、土壤有效氮含量和水分节约最有益。

Effects of Irrigation and Nitrogen Application on Spring Wheat Yield, Soil Water Content and Available Nitrogen Content in Loess Plateau of Central Gansu

The aim is to study the best combination of irrigation and nitrogen application affecting the yield of wheat. Spring wheat ‘Dingxi 42’ was used as material. Water-nitrogen interaction method was adopted with four kinds of irrigation quantities (water depth per unit area 50 mm, 100 mm, 150 mm and 200 mm) and three fertilizer application methods (40 kg/hm ² pure nitrogen fertilizer at jointing stage, 40 kg/hm ² pure nitrogen fertilizer at flowering stage, 40 kg/hm ² and 50 kg/hm ² pure nitrogen fertilizer at jointing stage and flowering stage). (1) The yields of wheat were all the highest when the irrigation amount was 150 mm and the nitrogen fertilizer was 40 kg/hm ² at flowering stage. (2) The water content of the three soil layers were the highest when the irrigation amount was 150 mm, the order of water content in three soil layers was tillering stage < flowering stage < jointing stage under different nitrogen application treatments. (3) The water consumption of wheat plant increased with the increase of irrigation, water use efficiency decreased with the increase of irrigation amount. (4) When irrigation amount was 150 mm at tillering stage, nitrate nitrogen content in three soil layers was the highest; at jointing stage, the content of ammonium nitrogen and nitrate nitrogen in 0-10 cm soil layer was the highest; at flowering stage, nitrate and ammonium nitrogen contents in three soil layers were the highest when the irrigation amount was 150 mm and pure nitrogen fertilizer was 40 kg/hm ². The combination of 150 mm irrigation depth per unit area and 40 kg/hm ² pure nitrogen fertilizer application at flowering stage is the most beneficial to the yield of spring wheat, soil available nitrogen content and water conservation in Loess Plateau of Central Gansu.