中耕时间和深度对大豆光合特性及产量形成的影响

Effects of Intertillage Time and Depth on Photosynthetic Characteristics and Yield Formation of Soybean

【目的】针对东北北部地区大豆主产区早春低温、保墒能力差,导致单产水平较低等问题,探究玉米大豆轮作模式下不同中耕时间和深度对大豆田土壤温湿度、大豆光合特性指标和产量的影响,为大豆产量稳定提升提供有力支撑。【方法】试验于2019—2020年在黑龙江省鹤山农场进行,采用田间小区试验方法,以当地主栽品种黑河43为试验材料,设置4种不同的中耕处理:常规培土(T1)、提前培土(T2)、常规深松(T3)和提前深松(T4),研究中耕时间和深度对土壤温湿度、大豆叶面积指数、株高、气体交换参数、光合产物积累与分配和产量的影响。【结果】(1)在相同中耕深度的基础上,提前培土处理(T2)较常规培土处理(T1),盛花期(R2期)土壤温度和湿度分别提高5.88%—6.54%、3.57%—4.03%(P<0.05),鼓粒期(R6期)叶面积指数、株高和SPAD值分别提高9.48%—16.86%、5.40%—10.57%、2.39%—6.81%(P<0.05);与常规深松处理(T3)相比,提前深松处理(T4)显著提高R6期叶面积指数、株高、净光合速率(P_(n))籽粒干物质积累量及大豆产量。(2)在相同中耕时间的条件下,与T1处理相比,T3处理R2期土壤温度、湿度和R6期株高分别提高4.14%—6.42%、10.08%—13.19%和7.43%—8.29%(P<0.05),R5期后干物质积累量和同化贡献率分别提高49.75%和32.95%(P<0.05);与T2处理相比,T4处理各时期土壤温度、R6期叶面积指数、净光合速率(P_(n))、结荚期(R5期)后干物质积累量、同化贡献率和产量均显著增加,其中产量增幅度达5.03%—6.02%(P<0.05)。(3)比较不同中耕措施,与T1处理相比,T4处理R2期土壤温度和湿度分别提高11.68%—17.15%和4.70%—8.66%(P<0.05),R6期叶面积指数、株高、SPAD分别提高12.64%—27.42%、11.67%—13.50%、5.43%—6.87%(P<0.05);T2、T3、T4处理提高R6期气体交换参数和大豆产量,其中T4处理净光合速率(P_(n))提高14.25%—29.68%(P<0.05)、产量增幅达10.69%—18.71%(P<0.05)。【结论】提前深松处理(T4)能够改善土壤温度和湿度,提高气体交换参数,促进植株净光合产物积累,延缓叶片衰老,提高大豆产量,适宜于东北北部旱作农业区推广应用。

【Objective】Aiming at the low temperature in early spring and poor moisture retentionability of main soybean producing areas in the northern part of Northeast China,the effects of different intertillage times and depths on soil temperature and humidity,photosynthetic characteristics and yield of soybean field under maize-soybean rotation mode were explored to provide a strong support for the stable improvement of soybean yield.【Method】The experiment was carried out in Heshan farm,Heilongjiang province from 2019 to 2020.The plot experiment method was adopted,and Heihe 43,the main local cultivator,was used as the test material.Four different intertillage treatments were set up:conventional earthing-up(T1),advanced earthing-up(T2),conventional subsoiling(T3),and advanced subsoiling(T4).The effects of intertillage time and depth on soil temperature and humidity,plant leaf area index and height,gas exchange parameters,accumulation and distribution of photosynthetic products and yield of soybean were studied.【Result】(1)On the basis of the same intertillage depth,compared with T1,soil temperature and humidity in flowering stage(R2 stage)under T2 increased by 5.88%-6.54%and 3.57%-4.03%(P<0.05),respectively,and leaf area index,plant height and SPAD values in seed-filling stage(R6 stage)were increased by 9.48%-16.86%,5.40%-10.57%and 2.39%-6.81%(P<0.05),respectivley.Compared with T3,T4 significantly increased leaf area index,plant height,net photosynthetic rate(P_(n)),grain dry matter accumulation and soybean yield at R6 stage.(2)Compared with T1,T3 increased soil temperature and humidity in R2 stage by4.14%-6.42%,10.08%-13.19%and plant height in R6 stage by 7.43%-8.29%(P<0.05),respectively.After pod-setting stage(R5stage),dry matter accumulation and assimilation contribution rate increased by 49.75%and 32.95%(P<0.05),respectively.Compared with T2,T4 significantly increased soil temperature,leaf area index at R6 stage,net photosynthetic rate(P_(n)),dry matter accumulation after R5 stage,assimilation contribution rate and yield,among which the yield increased by 5.03%-6.02%(P<0.05).(3)Compared with T1,T4 increased soil temperature and humidity by 11.68%-17.15%and 4.70%-8.66%in R2 stage(P<0.05),respectively.Leaf area index,plant height and SPAD in R6 stage were increased by 12.64%-27.42%,11.67%-13.50%and5.43%-6.87%(P<0.05),respectively.T2,T3 and T4 increased gas exchange parameters and yield in R6 stage,and net photosynthetic rate(P_(n))under T4 treatment increased by 14.25%-29.68%,and yield increased by 10.69%-18.71%(P<0.05).【Conclusion】T4 could improve soil temperature and humidity,increase gas exchange parameters,promote plant net photosynthate accumulation,and delay leaf senescence,finally increase soybean yield,which was suitable for the promotion and application of dry farm areas in the north of Northeast China.