关中灌区冬小麦混种的产量及农田土壤水分利用效率

Production of mixed planting winter wheat and soil water efficiency in Guanzhong Irrigation Zone

为探明不同冬小麦品种混种对产量和水分利用效率的影响。选用冬小麦西农979、小偃22、矮抗58和西农889,于2013—2014和2014—2015两年在西北农林科技大学斗口试验站开展田间试验,设置4个水平:单播(1L)、2个品种混种(2L)、3个品种混种(3L)和4个品种混种(4L),系统测定并比较不同混种水平群体生物量、子粒产量和农田土壤水分利用效率等。结果表明,灌浆期的混种群体光截获率、旗叶SPAD值、净光合速率和瞬时水分利用效率均显著大于单作群体。混种群体子粒产量和地上生物量均高于单作群体,子粒产量增幅随混种品种数量的增加逐渐降低,两年平均增幅为7.92%(2L)、7.15%(3L)和2.73%(4L),其中2L和3L达显著水平,地上生物量增幅随混种品种数量的增加逐渐升高,两年平均增幅为1.08%(2L)、4.78%(3L)和7.24%(4L),3L和4L达显著水平,通径分析表明混播下子粒产量的增加得益于单位面积穗数和穗粒数增加。混种增加了群体浅层土壤含水量和深层土壤中的根系分布,显著降低群体耗水量,并显著提高群体水分利用效率(WUE),子粒WUE两年平均提高11.93%(2L)、12.39%(3L)和8.72%(4L),地上干物质WUE两年平均提高3.3%(2L)、8.66%(3L)和11.75%(4L)。不同品种冬小麦混种可以提高水分利用效率,增加子粒产量。

The field experiments were conducted in 2013-2014 and 2014-2015 at Doukou Experimental Stationof Northwest A＆F University to explore effects of mixed planting of four cultivated winter wheat varieties （ Xinong 979, Xiaoyan 22, Aikang 58 and Xinong 889） on population yield and water use efficiency. The above-ground biomass of pop-ulation, grain yield, water use efficiency were detemiined with pure stands of each variety （lL ） , mixture of two varieties （2L） , mixture of three varieties （3L） and mixture of four varieties （4L） . Results indicated that the canopy light inter-ception rate, flag leaf SPAD value, net photosynthetic rate and instantaneous WUE of mixed population were significantly higher than those of monoculture group during filling period. Grain yield and above-ground biomass of mixed population were higher than those of monoculture group. The grain yield decreased with the increase in mixed level, and the average increase in two years were 7.92%（2L ） , 7.15% （3L ） and 2.73% （4L ） respectively, with the increase of 2L and 3L reaching significant level. Above-ground biomass showed an rising trend with the increase in mixed level , and the aver-age increase in two years were 1.08 % （2L ） , 4.78%（3L） and7.24%（4L） respectively, with the increase of 3 L and 4L reaching significant level. The increase in grain yield was attributed to the augment of spike number （per area） and ker-nel （per spike） . Mixed planting increased water content of upper soil layer and root distribution in deeper soil layer, and significantly decreased water consumption of population during whole growth period. Besides, mixed planting improved water use efficiency（WUE） , average WUE of grain in two years increased by 11.93% （2L） , 12.39 % （3L） and 8.72% （4L） , and average WUE of above-ground biomass in two years increased by 3.3% （2L ） , 8.66%（3L ） and 11.75% （4L ） respectively. It is concluded that mixed planting of cultivated winter wheat varieties could increase grain yield with better water use efficiency.