【作者】 靳奇峰；

【导师】 牛俊义；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2003， 硕士

【摘要】 通过管栽模拟试验，研究了施肥深度对地膜栽培春小麦根系生长，根冠关系及叶片衰老的影响，取得的主要研究结果有： (1)氮、磷施肥深度加深导致地膜春小麦全生育期不同层次根长、根干重及总根长、总根重变化不同。从各土层根长，根干重在不同生育期的变化看，局部施肥使根系在施肥土层明显增多。随氮、磷施肥深度的相对加深，中下层根长与根干重均大于表层施氮、磷，总根长与总根干重也显著增加。在开花至成熟期间，70cm以下土层，20～40cm施氮处理的根长比0～20cm施氮处理长56.95～34.94％，根干重高28.32～42.61％，总根长大16.1～12.94％，总根干重高10.57～16.70％；40～60cm施氮处理根长比0～20cm施氮长35.00～52.18％，根干重高32.29～57.58％，总根长大14.96～12.39％，总根干重高8.88～16.95％；20～40cm施磷处理比0～20cm施磷根长大23.30～15.01％，根干重高38.32～28.04％，总根长大6.18～9.45％，总根干重多11.53～14.15％；40～60cm施磷处理比0～20cm施磷根长大34.26～21.03％，根干重高56.44～37.8％，总根长大7.75～9.29％，总根干重高13.59～13.73％。在氮、磷相同施肥深度下，70cm以下各土层根长与根干重始终为施磷大于施氮，且施磷处理的总根长与总根干重始终大于施氮处理。 (2)随氮、磷施肥深度的相对加深，深层施氮与施磷均改变了根系在土壤中的分布，使根系生长下移，有利于根系吸收深层土壤中的水分和养分，且施磷处理中下层根系的分布大于施氮。从不同层次根长占各自总根长的百分数来看，在开花期，上层根(0～40cm)0～20cm施氮(50.96％)＞20～40cm施氮(45.84％)＞40～60cm施氮(39.58％)，0～20cm施磷(45.28％)＞20～40cm施磷(39.57％)＞40～60cm施磷(31.34％)，下层根(70～100cm)40～60cm施氮(21.23％)＞20～40cm施氮(20.28％)＞0～20cm施氮(17.47％)，40～60cm施磷(34.65％)＞20～40cm施磷(31.2％)＞0～20cm施磷(25.16％)。在成熟期，上层根0～20cm施氮占40.6％，大于20～40cm施氮7.23％，大于40～60cm施氮15.92％；0～20cm施磷占33.75％，大于20～40cm施磷3.01％，大于40～60cm施磷9.06％，下层根0～20cm施氮为28.33％，小于20～40cm施氮5.52％，小于40～60cm施氮10.04％；0～20cm施磷为38.35％，小于20～40cm施磷1.95％，小于40～60cm施磷4.12％。 (3)从分蘖期至开花期，根冠比表层施氮、磷大于深层施氮、磷处理；灌浆到成熟期，深层施氮、磷根冠比大于表层施氮、磷。在成熟期，20～40cm施氮大于0～20cm施氮2.99％，40～60cm施氮大于0～20cm施氮3.29％，20～40cm施磷根冠比大于0一20em施磷1 .3%，40一60em施磷大于0一20em施磷5.46%。施氮处理根冠比在各时期始终小于施磷处理，根冠比在分孽期施磷处理大于施氮处理巧.92%，在开花期大于巧.67%，在成熟期大于7.犯%。在相同施肥深度下，施磷处理根冠比大于施氮根冠比。 (4)深层施用氮、磷肥，均提高了叶片廿卜绿素、蛋白质含量，降低了叶片丙二醛含量，减小了细胞膜透性。在开花期，20一40cm施氮叶片叶绿素、蛋白质含量分别大于0~20cm施氮5.52%和2.33%，40一6Ocm施氮分别大于0一20cm施氮2.76%和1 .81%;20一4Ocm施磷叶片叶绿素、蛋白质含量分别大于0一20cm施磷4.12%和3.11%，40~60em施磷分别大于0一20em施磷5.94%和1.62%。滩月同施肥深度下，施氮处理叶片叶绿素、蛋白质含量大于施磷处理，丙二醛含量小于施磷处理，细胞膜透性大于施磷处理。 (5)深施氮、磷肥均提高了单株叶面积，在相同施肥深度下，施氮处理叶面积大于施磷处理2.680k一9.02%。随施肥深度的加深，在地膜春小麦生育期，单株干物质产量均大于表层施氮、磷，施氮处理干物重大于施磷处理。施肥处理花后干物质来源占籽粒的百分数，40一60cm施磷为73 .33%，大于20一40cm施磷2.30%，大于0~20em施磷4.10%;40一60cm施氮为72.13%，大于20~40em施氮2.23%，大于O一20cm施氮5.25%，深施磷肥对后期小麦的生长与产量的形成影响更大。在成熟期，o一20cm施氮处理籽粒产量为1 .549/株，比20一40cm和40一60cm施氮处理分别降低23.00y0和18.09%;0一20cm施磷处理籽粒产量为1.43g/株，比20一40cm及40一60cm施磷处理分别降低26.67%和23.49%。但在相同施肥深度下，施氮处理籽粒产量大于施磷处理。更多还原

【Abstract】 Through the simulated experiment of tube cultivation, this paper studies the effect of fertilizer application depth on root growth, the relations between root and crown,and leaf senescence in spring wheat mulched with plastic film. The major research findings are as follows:(1) Deepening the depth of applying fertilezer of nitrogen and phosphorus results in the changes and differences in root length of different stratification, dry weight root, total root length and total dry weight root of spring wheat mulched with plastic film ?during growing stage. Seen from the changes in root length, dry weight root,in different soil layders in their growing stage, applying fertilizer partly makes the number of roots increase the soil layer where fertilizer is applied. With the relatively deepening of the depth of nitrogen and phosphorus application, the root length and dry weight of the middle and lower stratification exceed that of fertilizer application on surface, and the total root length and dry weight root increases obviously. During anthesis and mature stage, in the soil layer under 70cm, the root lergth of nitrogen application between 20~40cm is 56.95-34.94%, longer than that between 0~20cm, the weight of dry root is 28.32-42.61%, higher, the total root length is 16.1-16.70%; the root length of nitrogen application between 40cm~60cm is 35-52.18% longer than that between 0~20cm. The weight of dry root is 32.29-57.58% heavier, the total root length is 14.96-12.39% longer, the total weight of dry root is 8.88-16.96% heavier, the root length of phosphorus application between 20~40cm is 23.30-15.01% longer than that between 0~20cm; the weight of dry root is 83.32-28.04% heavier; the total root length is 6.18-9.45% longer; the total weight of dry root is 11.53-14.15% heavier; The root length of phosphorus application between 40~60cm is 34.26-21.03% longer that between 0~20cm; the weight of dry root is 56.44-37.8% heavier; the total root length is 7.75-9.29% longer. At the same depth of nitrogen and phosphorus application, the root length and weight of dry root in different soil layer under 70cm which is applied phosphorus are longer and heavier than that is applied nitrogen. So do the total root length and the total weight of dry root.(2)With the relatively deepening of the depth of nitrogen and phosphorus application, their application in deep stratification changes the distribution of root in soil, and makes root grow deeper. So it is good for root to absorb moisture and nutrient from deep soil. And the distribution of root in middle and lower stratification applied phosphorus is wider than that applied nitrogen. Seen from the percentage of the root length in its total root length, during anthesis, root high stratification between 0’40cm, from Ocm to 20m, nitrogen application (50.96%) is more than that (45.84%) from 20~40cm which is more than that (39.58%) from 40cm to 60cm, phosphorus application (45.28%) is more than that (39.57%) from 20cm to 40cm which is more than that (31.34%) from 40cm to 60cm, root of lower stratification between 70-100cm, nitrogen application (21.23%) from 40cm to 60cm is more than that (20.28%) from 20cm to 40cm which is more than that (17.47%) from Ocm to 20cm, phosphorus application (34.65%) from 40cm to 60cm & more than that (31.2%) from 20cm to 40cm which is more than that (25.16%) high stratification from Ocm to 20cm, Nitrogen application is 40.6%, it is more than that (7.23%) from 20cm to 40cm, is more than that (15.92%) from 40cm to 60cm, phosphorus application from Ocm to 20cm is 33.75% it is more than that (3.01%) from 20cm to 40cm, also more than that (9.06%) nitrogen application is 28.33%, it is less than-that (5.52%) from 20cm to 40cm, also less than that (10.04%) from 40cm to 60cm; phosphorus application is 38.35% from Ocm to 20cm, it is less than that (1.95%) from 20cm to 40cm, also less than that (4.12%) from 40cm to 60cm.(3) From the stooling stage to anthesis root-crown ratio on surface nitrogen and phosphorus application is higher than that in deep stratificatio更多还原