稻秸还田年数和氮肥运筹对小麦出苗和幼苗形态及生理特性的影响

为探究稻秸还田条件下培育小麦壮苗的技术措施,设计稻秸还田年数和氮肥运筹方式二因素试验,研究稻秸还田年数和氮肥运筹组合对小麦扬辐麦4号幼苗和相关生理特性的影响。结果表明,稻秸还田后小麦出苗率较不还田(CK)降低5.4～10.6个百分点(2017-2018,F=5.96^**)、4.9～8.6个百分点(2018-2019,F=15.79^**),稻秸还田还影响小麦3叶期幼苗的正常生长,随着稻秸还田年数的增加不利影响有所减轻,但不能消除;稻秸还田年数及氮肥运筹对小麦6叶期幼苗质量有一定影响,稻秸还田减少小麦6叶期幼苗的叶面积指数(LAI)、单株分蘖数、苗高和单株干物重,抑制小麦正常生长,但随着还田年数的增加,不利影响逐渐减弱,还田年数最高处理的LAI、单株分蘖数、苗高和单株干物重较还田1 a处理分别提高0.2～0.4、0.2～0.4、1.3～1.9 cm和26.3～55.6 mg/株;稻秸还田条件下,适量提高壮蘖肥的施用量能够提高小麦根系活力,增加叶片SPAD值,增加叶鞘、叶片中的可溶性糖含量,减少丙二醛(MDA)的累积,且随着还田年数增加,影响随之增...

Effects of Rice Straw Returning and Nitrogen Fertilizer on Seedling Emergence and Morphological and Physiological Characteristics of Wheat

In order to study the ways of cultivating strong seedlings of wheat under the condition of rice straw returning, Yangfumai 4 was selected as the experimental material, and the years of rice straw returning and the methods of nitrogen fertilizer management were designed to study their effects on the quality and related physiological characteristics of wheat seedlings. The results showed that the emergence rate of wheat seedlings in the rice straw returning treatment was lower than that of no straw returning treatment by 5.4~10.6 percentage points (2017-2018, F=5.964**) and 4.9~8.6 percentage points (2018-2019, F=15.79**). Rice straw returning also had an effect on the growth of three-leaf stage wheat seedlings. The effects decreased slightly with the extension of rice straw returning years, but could not be completely eliminated. Rice straw returning lasting for different years and nitrogen fertilizer management had an impact on the quality of six-leaf stage wheat seedlings. Rice straw returning reduced the LAI value, the number of tillers, seedling height, and dry matter weight per plant of wheat seedlings at 6-leaf stage, in addition to affect the growth of wheat. However, with the years of straw returning increasing, the adverse influence on wheat seedling growth gradually decreased. The LAI value, the number of tillers, seedling height and dry matter weight per plant of wheat seedlings in the highest returning year treatment were 0.2~0.4, 0.2~0.4, 1.3~1.9 cm and 26.3~55.6 mg higher than those in the lowest returning year treatment, respectively. Under the condition of rice straw returning, appropriately increasing the application amount of strong fertilizer could increase the root activity of wheat, the chlorophyll content of leaves, the soluble sugar contents in leaf sheaths and leaves, and reduce the accumulation of MDA, which was beneficial to the growth of wheat seedlings, which was enhanced with the increasing years of straw returning. Rice straw returning for over four years, combined with nitrogen application mode (the ratio 5:2:2:1 of base fertilizer, strong tiller fertilizer, jointing fertilizer and booting fertilizer), was conducive to the cultivation of strong seedlings. The results of the study provide appropriate measures for rice-straw returning, so as to achieve strong seedlings and high yield.