减氮节水对宁夏引黄灌区春小麦光合特性与产量的影响. (Chinese)

Excessive input of nitrogen fertilizer and low water use efficiency have posed a great threat to the spring wheat production in Yellow River Irrigation District of Ningxia Hui Autonomous Region, Western China. Therefore, this study aims to explore the effects of water-saving irrigation on the population dynamics, photosynthetic characteristics, and the yield of spring wheat under the background of nitrogen reduction. Taking the Ningchun No. 4 as the test material, a systematic field test was carried out at three nitrogen application levels: conventional nitrogen application (270 kg/hm², NC), reduced nitrogen fertilizer 25% (202.5 kg/hm², NJ), and no nitrogen fertilizer (0 kg/hm², N0). Three irrigation scenarios were also set with the water quotas: conventional irrigation (400 mm, WC), water saving 20% (320 mm, W1), and water saving 40% (240 mm, W2). The results showed that: 1) There were no significant differences in the total number of stems in different irrigation treatment groups at the same nitrogen fertilizer level. Nevertheless, an outstanding increase was found in the total number of stems in the population with the conventional nitrogen application and nitrogen reduction level under the same irrigation quotas, compared with the non-nitrogen treatment. The nitrogen reduction and water-saving treatment also maintained a far higher total number of group stems, thereby improving the incidence of tillers. 2) There was no outstanding effect of 25% less nitrogen on the growth and development of spring wheat, compared with the conventional nitrogen application. More importantly, the 20% saving water greatly contributed to the plant height and leaf area of spring wheat for the higher accumulation of dry matter. 3) The 20% reduced nitrogen and saving water were also beneficial for the soil plant analysis development (SPAD) value and photosynthetic characteristics of the leaves, particularly significantly higher than that in the water saving by 40%. There was no significant difference between the nitrogen reduction level and the conventional nitrogen application in the SPAD value and photosynthetic index of spring wheat leaves. 4) The maximum number of grains per ear (42.87 grains) and 1 000-grain mass (54.28 g) were achieved by the saving 20% of water at the nitrogen reduction level among all the water and nitrogen treatments. The highest yield of spring wheat also reached 8 092.52 kg/hm². The yield was not significantly decreased during the water saving of 20%, respectively, compared with the conventional nitrogen application and conventional irrigation treatment. Consequently, the 25% reduced nitrogen and 20% saving water can be expected to obtain a higher yield during spring wheat production with fewer nitrogen resources in the Ningxia Yellow River irrigation area. Therefore, it is suggested to be an effective local nitrogen irrigation scheme for the higher yield of spring wheat production. [ABSTRACT FROM AUTHOR]

针对宁夏引黄灌区春小麦生产中氮肥投入过量及水资源利用效率低的问题，探究减氮背景下节水灌溉对春小麦 群体动态、光合特性及产量的影响。2021 年以宁春4 号为供试材料，分别设置3 个施氮水平（常规施氮270 kg/hm²、减 施氮肥25%和不施氮）和3 个灌溉定额（常规灌溉400 mm、节水20%和节水40%）。结果表明：1）同一氮肥水平下不 同灌溉处理的群体总茎数均无显著性差异；同一灌溉定额水平下常规施氮和减氮水平处理的群体总茎数均显著高于不施 氮处理，但二者无显著差异，减氮节水处理亦能维持较高的群体总茎数和茎蘖成穗率。2）与常规施氮相比，减氮25%对 春小麦的生长发育无明显影响，在此基础上节水20%并不会降低春小麦株高，叶面积的生长，不会减少春小麦干物质累 积量。3）减氮水平与常规施氮处理的春小麦叶片SPAD 值和光合指标无明显差异，减氮水平下节水20%处理的叶片SPAD 值和光合指标同常规灌溉无显著差异，但显著高于节水40%处理。4）所有水氮处理中减氮水平下20%节水处理的穗粒数 和千粒质量最高，春小麦产量达8 092.52 kg/hm²，与常规施氮常规灌溉处理的产量无显著差异。减氮25%节水20%处理 的灌溉施肥模式，既可获得较高产量又可以节约水氮资源，达到了宁夏引黄灌区春小麦生产中减氮、节水、稳产的目的。 因此，可作为当地适宜的施氮灌溉方案。 [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)