轮耕对宁南旱区冬小麦花后旗叶光合性能及产量的影响

Effects of Rotational Tillage on Flag Leaf Photosynthetic Characteristics and Yield After Anthesis of Winter Wheat in Arid Areas of Southern Ningxia

【目的】探索免耕/深松隔年轮耕模式对冬小麦花后光合性能及产量的影响。【方法】采用免耕/深松/免耕、深松/免耕/深松、传统翻耕3种耕作处理,在宁南旱区进行连续4年定位试验,2010年测定小麦花后土壤水分、旗叶面积、叶绿素相对含量、光合特性和产量的变化。【结果】与传统耕作相比(对照),小麦开花期和灌浆期免耕/深松/免耕、深松/免耕/深松处理的0—200 cm土壤贮水量平均分别增加15.24%、23.45%(P<0.05);旗叶面积和相对叶绿素含量平均分别提高12.78%、8.89%和25.20%(P<0.05)、11.19%;旗叶日均净光合速率(Pn)平均分别提高1.55和1.68μmol.m-2.s-1(P<0.05);旗叶日均蒸腾速率(Tr)平均分别提高0.44和0.58mmol.m-2.s-1(P<0.05);而小麦旗叶日均水分利用效率(WUE)差异不显著(P>0.05)。在灌浆期,两种轮耕模式均保持了较高的最大光化学效率(0.52)、PSⅡ实际光化学效率(0.40)和光合电子传递速率(92.67)。两种轮耕模式的小麦籽粒产量分别较传统耕作增加6.88%和11.98%(P<0.05)。【结论】在干旱缺水条件下,不同轮耕模式小麦花后都显示出良好的蓄水保墒能力和较高的光合特性,显著提高小麦的产量,是宁南旱区较为适宜的土壤耕作模式。

[Objective] The objective of the experiment is to seek the effects of no-tillage （NT）/Subsoiling （ST） rotational tillage system every other year on photosynthetic capacity and yield after anthesis of winter wheat. [Method] Based on three tillage treatments of NT/ST/NT, ST/NT/ST and conventional tillage （CT） in arid areas of southern Ningxia, it was investigated by measuring soil water, flag leaf area, chlorophyll relative content, photosynthetic characteristics, chlorophyll fluorescence parameters and yield under different soil tillage treatments after anthesis of wheat in 2010. [Result] Compared with conventional tillage （CK）, the soil water storage in 0-200 cm soil layers of NT/ST/NT and ST/NT/ST was significantly increased by an average of 15.24% and 23.45% at flowering stage and filling stage of wheat, their flag leaf area and chlorophyll relative content were increased by an average of 12.78%, 8.89% and 25.20%, 11.19% （P〈0.05）, respectively; their flag leaf daily average photosynthesis rate （P,） was increased by an average of 1.55 and 1.68 umol·m-2·s-1 （P〈 0.05）, their flag leaf daily average transpiration rate （Tr） was increased by an average of 0.44 and 0.58 mmol·m·s-1 （P〈0.05）, but, their flag leaf daily average water use efficiency （WUE） showed no obvious difference. At filling stage, two rotational tillage treatments had a higher level of maximal photochemical efficiency of PS II in the darkness （0.52）, actual photochemical efficiency of PS II in the light （0.40） and photosynthetic electron transport rate （92.67）. Compared with conventional tillage, the different rotational tillage system achieved wheat grain yield increment of 6.88% and 11.98% （P〈0.05）. [Conclusion] The different rotational tillage systems all showed better soil water conservation ability and high photosynthetic capacity after anthesis of wheat, significantly increased wheat yield under condition of drought and water shortage. So, the different rotational tillage system is a more suitable soil tillage system in arid areas of southern Ningxia.