深松措施下磷肥下移提高春玉米磷效率的生理机制汇报人:张瑞富内蒙古民族大学一、研究背景1.玉米生产的重要性2.玉米磷肥施用情况3.土壤有效磷垂直分布4.深松是玉米高产栽培的有效措施5.高产玉米根系特征1.玉米生产的重要性西辽河平原是我国为数不多的井灌玉米区。玉米种植面积在1500万亩以上,总产在150亿斤左右,约占本地区粮食总产的85%以上,占内蒙古自治区玉米产量的30%左右,平均单产较全国高近40%。在种植业结构调整的背景下,玉米削减主要是粮改饲,改种其他作物选择余地不大。2.玉米磷肥施用情况西辽河平原为石灰性土壤,土壤有效磷含量相对较低,高量施磷成为玉米高产栽培的必然行为,玉米高产与磷高效的矛盾突出。玉米纯磷施量一般在6公斤/亩左右,有的高达10公斤/亩。3.土壤有效磷垂直分布处理0-10cm10-20cm20-30cm旋耕玉米地(21块)12.386.885.84秸秆还田地(5块)8.417.787.91休闲草地(1块)22.1116.9215.83玉米生产中长期采用小动力农机具旋耕灭茬和机械带肥播种,磷肥施用深度只有6-7cm,多年的累积效应导致磷素养分在土壤表层富积而下层不足。4.深松是玉米高产栽培的有效措施西辽河平原地区土壤耕层深度仅为13.7cm。深松打破犁底层,改善土壤的通透性,促进根系生长,是玉米高产高效的主要技术措施之一。5.高产玉米根系特点当代玉米品种的根系呈现“横向紧缩,纵向延伸”的特点(王空军等,2001);玉米新品种在深层土壤中的根系分布增加,根系下扎能力增强(Campos等,2004;Hammer等,2009);超高产栽培玉米(密度)较普通高产栽培玉米的下层根系分布比例更高(张玉芹等,2011;齐文增等,2012)。根系对磷的活跃吸收层大口期在10-20cm,乳熟期下移到20-40cm土层(陈学留等,1986)。磷肥下移调控可实现磷素养分供需在时空上的耦合,提高春玉米对磷肥的吸收和利用效率。科学假设二、试验设计1.深松对玉米根系影响试验2.土柱栽培下施磷深度试验3.土柱栽培下分层施磷试验4.大田栽培下分层施磷试验5.大田栽培下施磷深度试验测定项目根系形态特征根冠生理特性物质积累与转运磷含量及积累量产量及其构成因素磷效率0.01.02.03.04.05.06.07.0V6V12R1R3R6生育时期Growthstage叶面积指数LAIRS+R0.01.02.03.04.05.06.07.0V6V12R1R3R6生育时期Growthstage叶面积指数LAIRS+R0.01.02.03.04.05.06.07.0V6V12R1R3R6生育时期Growthstage叶面积指数LAIRS+R0.01.02.03.04.05.06.07.0V6V12R1R3R6生育时期Growthstage叶面积指数LAIRS+R深松提高了春玉米大喇叭口期后的叶面积指数,叶面积指数高值维持期变长,叶片衰老减缓。三、结果与分析图1深松对春玉米叶面积指数的影响aaaaaaaabaab0510152025102030102030土层深度Soildepth根幅(cm)RootwidthRS+Raaaaaaaaaaab0510152025102030102030土层深度SoildepthRS+R郑单958郑单958先玉335先玉335a.2013年株间b.2013年行间c.2014年株间郑单958先玉335先玉335郑单958aaaaaabaabab0510152025102030102030土层深度Soildepth根幅(cm)RootweidthRR+SAbaaaaBaabaa0510152025102030102030土层深度SoildepthRR+Sd.2014年行间30cm土层处根幅均表现为深松处理低于旋耕处理。旋耕措施下犁底层使得根系垂直下扎困难而被迫侧向伸展,是导致30土层处根幅旋耕处理低于深松处理的主要原因。图2深松对春玉米根幅的影响品种Varetiy时期Stage耕作方式Tillage根干重Rootdryweight总和Total0~2020~4040~6060~8080~100郑单958V12R10.69±0.20A0.83±0.05a0.35±0.11a----11.87±0.27aS+R9.69±0.31B0.95±0.17a0.36±0.08a----11.00±0.24bR1R16.75±1.38a0.76±0.09a0.34±0.08b0.20±0.07a0.17±0.09a18.22±1.13aS+R16.27±0.62a0.75±0.11a0.61±0.12a0.22±0.10a0.19±0.06a18.04±0.91aR3R12.07±0.21B0.71±0.05b0.30±0.05b0.22±0.05b0.14±0.04b13.44±0.39BS+R14.03±0.59A0.87±0.06a0.49±0.10a0.34±0.09a0.25±0.03a15.98±0.79AR6R9.55±0.47b0.33±0.06B0.12±0.03b0.06±0.03b--10.06±0.51BS+R11.38±0.44a0.74±0.12A0.35±0.07a0.28±0.11a0.15±0.0412.90±0.75A先玉335V12R8.84±0.56a1.05±0.12a0.44±0.04b----10.33±0.98aS+R8.89±0.27a0.99±0.14a0.56±0.07a----10.44±0.51aR1R17.49±0.35A0.87±0.13a0.54±0.08a0.25±0.04b0.22±0.03a19.37±0.26aS+R16.38±0.22B0.91±0.21a0.58±0.19a0.38±0.04a0.29±0.07a18.54±0.34bR3R11.59±0.91a0.77±0.13a0.36±0.08b0.29±0.08B0.10±0.03b13.11±0.12bS+R11.64±1.02a0.81±0.10a0.65±0.05a0.63±0.07A0.27±0.06a14.00±0.42aR6R8.85±0.76b0.40±0.07b0.17±0.05b0.08±0.01B--9.50±0.58bS+R9.70±1.03a0.71±0.13a0.45±0.11a0.29±0.07A0.16±0.0711.30±0.88a表1深松对春玉米不同土层根干重的影响品种Variety时期Stage耕作方式Tillage土层深度Soildepth(cm)0~2020~4040~6060~8080~100郑单958V12R90.066.992.95----S+R88.098.643.27----R1R91.934.171.871.100.93S+R90.194.263.281.221.05R3R89.815.282.231.641.04S+R87.805.443.072.131.56R6R94.933.281.190.60--S+R88.225.742.712.171.16先玉335V12R85.5810.164.26----S+R85.159.485.36----R1R90.294.492.791.291.14S+R88.354.913.132.051.56R3R88.415.872.752.210.76S+R83.145.794.644.501.93R6R93.164.211.790.84--S+R85.766.283.982.561.41表2深松对春玉米不同土层根干重分布比例的影响0204060801000-2020-4040-6060-8080-1000-2020-4040-6060-8080-100根系活力(ug·g-1·h-1)Rootvigor土层深度SoildepthRS+R0204060801000-2020-4040-6060-8080-1000-2020-4040-6060-8080-100土层深度SoildepthRS+R0204060801000-2020-4040-6060-8080-1000-2020-4040-6060-8080-100根系活力(ug·g-1·h-1)Rootvigor土层深度SoildepthRS+R0204060801000-2020-4040-6060-8080-1000-2020-4040-6060-8080-100土层深度SoildepthRS+R郑单958先玉335郑单958先玉335郑单958先玉335郑单958先玉335图3深松对春玉米根系活力的影响品种Variety酶Enzyme耕作方式Tillage酶活性Activityofenzyme0~2020~4040~6060~8080~100郑单958SOD(U·g−1)R157.10±38.11a138.13±12.68a103.65±21.23a96.18±8.36a116.32±1.53aS+R152.57±15.75a134.24±6.89a119.12±8.69a102.12±19.13a126.85±9.69aPOD(U·g−1)R67.00±6.32a64.00±5.31a60.00±3.23a52.85±5.61a50.50±2.36bS+R73.00±7.18a60.88±4.16a64.00±1.96a59.50±7.13a77.50±1.82aMDA(μmol·g−1)R7.88±1.31a6.77±0.96a6.62±1.01a5.90±0.36a5.67±0.12aS+R7.14±0.64a6.52±1.21a5.89±0.28a5.81±0.28a5.04±0.37b先玉335SOD(U·g−1)R152.97±23.68a142.96±31.60a130.74±41.35a107.99±1.68a128.28±13.13aS+R164.44±8.53a156.32±28.36a136.88±10.13a118.96±10.26a133.70±10.26aPOD(U·g−1)R74.50±1.93a72.00±9.10a71.00±8.78a42.19±6.54b47.00±6.39aS+R75.38±10.28a78.00±1.22a71.50±6.77a67.00±1.68a55.00±5.68aMDA(μmol·g−1)R7.18±0.98a6.97±0.91a6.51±1.26a5.95±0.55a5.48±0.22aS+R6.98±2.01a6.94±1.22a6.37±0.37a5.77±0.64a5.17±1.01a表3深松对春玉米吐丝期不同土层根系酶活性的影响品种Variety年份Year耕作方式Tillage有效穗数EffectiveSpike/(104·hm-2)穗粒数Grainnumberperspike千粒重1000-grainWeight/g产量ActualYield/(t·hm-2)郑单9582013R6.96±0.50a478.68±12.10a338.13±7.20b11.01±0.14BS+R6.71±0.07a496.96±33.41a361.66±11.36a11.93±0.09A2014R6.76±0.09a498.41±23.31a333.36±3.66b11.17±0.13BS+R6.67±0.15a530.82±20.46a354.75±9.31a12.19±0.17A先玉3352013R6.98±0.25a469.36±12.09a329.68±6.57b10.36±0.30bS+R6.87±0.71a478.78±11.15a346.31±6.82a11.02±0.10a2014R6.95±0.20a514.63±12.08b321.25±2.27B11.14±0.06bS+R6.76±0.14a545.22±24.46a334.67±3.56A11.99±0.03a