不同间套作模式对棉花产量和生物量累积、分配的影响

Effects of different intercropping systems on cotton yield,biomass accumulation,and allocation

发展棉花间套作体系是缓解我国黄河流域棉花与其他作物争地矛盾的主要策略,但目前对棉花间套作体系下棉花的增产机理尚不明确。因此,本研究通过田间试验设置了棉花与小麦、大蒜和花生间套作,并对其根系分别采取塑料膜分隔、尼龙网分隔和不分隔处理,从而研究在隔根处理下不同作物与棉花间作对棉花产量及生物量累积的影响。研究表明:(1)隔根处理下的不同作物与棉花间作的土地当量比(LER)大于1,说明试验中棉花间套作体系均体现出间作优势,且在小麦/棉花套作和大蒜/棉花套作的体系中,小麦和大蒜对于棉花的资源竞争力大于0,小麦和大蒜在共生期内是优势种;花生相对于棉花的资源竞争力小于0,在花生/棉花间作体系中,棉花是优势种。(2)在棉花盛蕾期,单作棉处理的棉花的叶、茎器官的干物质累积量多于其他3个处理,而在花铃期后,间套作体系中的干物质积累量多于单作棉处理,间套作体系中的棉花生殖器官干物质积累量高于单作棉处理。(3)盛蕾期和初花期,单作棉的茎、叶器官的分配率高于小麦套作棉花、大蒜套作棉花和花生间作棉花处理,在盛花期和盛絮期,处理间的差异不显著;不同种植模式下生殖器官干物质分配率的差异与茎、叶器官相反。相关研究结果可为间套作模式下的棉花间作优势的产生机理探究提供理论支持,为间套作体系生产力的提高提供科学依据。

The development of cotton intercropping system is the main strategy to alleviate the conflict between cotton and other crops for land in the Yellow River Basin of China,but the mechanism of cotton yield increases in cotton intercropping system is still unclear.In this study,a two-year field experiment with cotton-based intercropping systems(wheat/cotton,garlic/cotton,and peanut/cotton)and three root partitions(no,mesh,and plastic partitions)to study the effects of different crops intercropped with cotton on yield,biomass accumulation and allocation.The study showed that:(1)The land equivalent ratios(LERs)of different crops intercropped with cotton were greater than 1,indicating that the cotton intercropping system in the experiment had intercropping advantage.The resource competitiveness of wheat and garlic relative to cotton was greater than 0,indicating that wheat and garlic were dominant species in the co-growth period of wheat/cotton intercropping and garlic/cotton intercropping systems,whereas the resource competitiveness of peanuts relative to cotton was less than 0,indicating that cotton was dominant species in peanut/cotton intercropping system.(2)Dry matter accumulation of the leaf and stem in sole cotton cropping system was more than that of intercropping systems at bud stage,while the dry matter accumulation in intercropping systems was more than that in sole cotton cropping after the flowering and boll stages.The reproductive organs dry matter accumulation in intercropping systems was also higher than that in sole cotton cropping system.(3)The distribution rate of the stem and leaf in sole cotton was significantly higher than that in cotton intercropped with wheat,garlic,and peanut at bud stage and initial flowering stage,but the difference was not significant at full-bloom and open boll stages.However,the opposite pattern was observed in dry matter distribution rate of reproductive organs.These results can provide theoretical support for the mechanisms of cotton intercropping advantage and scientific basis for the productivity improvement of intercropping systems.