密度和修剪对冬小麦根系时空分布和产量的影响  

Effects of seeding rate and root pruning at different growth stages on spatiotemporal root distribution,soil water use and grain yield of winter wheat in Loess Plateau

作　　者：方燕[1,2] 徐炳成[1] 谷艳杰 刘倩倩[2] 李凤民[2] 

机构地区：[1]黄土高原土壤侵蚀与旱地农业国家重点实验室,水土保持研究所,西北农林科技大学,杨凌712100 [2]兰州大学生命科学学院,草地农业系统国家重点实验室,兰州730000

出　　处：《生态学报》2015年第6期1820-1828,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金(30625025);中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室基金(10501-1216)

摘　　要：田间试验研究了种植密度和不同时期根修剪对黄土旱塬冬小麦(Triticum aestivum L.)根系时空分布、土壤水分利用以及产量的影响。供试材料为该地区广泛种植的冬小麦品种长武135。试验设定4个密度处理:SR1、SR2、SR3和SR4,分别为180、225、280和340株/m2,其中SR2为常规密度;以及4个根修剪处理:CK(不剪根处理)、W(越冬期根修剪)、S(返青期根修剪)和B(越冬期根修剪+返青期根修剪)。研究结果表明,冬小麦返青期、孕穗期和花期根系总干重随种植密度的增加而增加。根修剪处理显著降低了各生育期冬小麦根系总干重,不同处理间排序为CK>W>S>B。种植密度和根修剪对冬小麦根系总长度的影响与根系总干重类似,各处理间根系总干重和根系总长度的差异主要来自于0—20 cm表土层。冬小麦表土层(0—20 cm)中的根干重密度(DRWD)和根长密度(RLD)都随种植密度的提高而增加。根修剪降低了返青期、孕穗期和花期冬小麦DRWD和RLD在0—20 cm表土层中的分布,但增加了花期60—100 cm深土层中的DRWD和RLD。整个生育期土壤水分消耗随种植密度增加而增加,而根修剪显著减少土壤水分的消耗。冬小麦的产量和水分利用效率随着种植密度增加而显著提高。根修剪处理显著增加了冬小麦的产量,且W处理的产量最高,同时根修剪也显著提高了冬小麦的水分利用效率。由此可见,越冬期根修剪(W)可以最大程度提高冬小麦产量。考虑到经济效益,建议旱地雨养农业区在较高的密度下进行越冬期根修剪处理,从而达到生产上高产高效的目的。This study was to investigate the effects of combined application of actinomycetes Act12 bio-control agents and potassium humate on growth and microbial flora in rooting zone of Salvia miltiorrhiza Bge. Taking conventional transplantation treatment as control,we used root dipping with actinomycetes Act12 bio-control agents and potassium humateto evaluate survival rate,biomass and resistance to root-knot nematode of S. miltiorrhiza; The abundances of soil bacteria（B）,fungi（F） and actionmycetes（A） were determined using the dilution plating technique. Predominant microorganisms were identified using 16 S rRNA and ITS sequence analysis. Results were used to evaluate the microecological changes in soil microflora of S. miltiorrhiza root zones with combined application of actinomycetes Act12 bio-control agents and potassium humate. The results showed that： 1） Under Act12 combined with potassium humate treatment（ T20）,emergence rate increased by 8. 7% compared with the control treatment,and mortality rate decreased by 39. 0%; Stem-leaf natural weight,root natural weight,root natural weight per plant,root dry weight and root dry weight per plant were 6. 1% 、28.6% 、11. 1% 、36. 3% and 9. 0% higher than the control,respectively. 2） Combined application of Act12 agents and potassium humate can adjust soil microecological balance,modify microflora and microbial community composition. In rhizoplane soil,compared with the control treatment,A / F increased by 95. 0% under Act12 combined with potassium humate treatment. In S. miltiorrhiza roots,under Act12 combined with potassium humate treatment,the number of bacteria was 195. 0% higher than the control. While fungi and actinomyctes were not detected. 3） In rhizosphere and rhizoplane soil with Act12 and potassium humate,6 predominant microorganisms might be beneficial,which included 3 bacteria isolates namely A. nitroguajacolicus, R. radiobacter and P. frederiksbergensis, 3 actinomycetes isolates namely S.diastatochromogenes,S. lateritius and S. cav

关 键 词：冬小麦(Triticum AESTIVUM L.) 根系 垂直分布 土壤含水量 黄土旱塬 

分 类 号：S512.11[农业科学—作物学]