【作者】 汪佳；

【导师】 黄高宝； 李玲玲；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2010， 硕士

【摘要】 本文以覆膜玉米为研究对象,将新膜处理设置了露地平作(NM)、半膜平作(HM)、全膜平作(CM)和全膜双垄沟播(CMRF)四个处理,将一年两用膜处理设置了免耕立茬(NTSS)、免耕立秆(NTMS)和免耕+秸秆覆盖(NTMC)三个处理,共七个处理。研究了不同覆膜和秸秆留茬方式对土壤全氮、硝态氮和全磷含量的时空变化及玉米植株氮、磷吸收、累积及运转规律的影响。旨在了解和掌握全膜双垄沟播玉米对养分的吸收及累积及土壤养分动态规律,为合理推广全膜双垄沟播栽培技术,揭示其高产的内在机理提供科学依据。主要的研究结果如下:1.覆膜处理为玉米根系生长提供了较好环境因子,全膜双垄沟播处理对深层养分的吸收能力最强,不同覆膜方式对玉米0~60cm磷素的吸收比影响不显著。覆膜处理中,7月至8月份全膜处理对40~60cm土层氮吸收最强,全生育期全膜双垄沟播处理对110cm以下土层氮影响最大。秸秆处理中全氮和全磷含量均以免耕秸秆覆盖最高。全膜双垄沟播处理全生育期20~40cm处全磷含量下降幅度为0.255g/kg,显著大于其他处理,110~140cm土层各处理全磷含量随生育期推进呈无规律缓慢下降,下降幅度以全膜双垄沟播处理(0.152g/kg)为高。全氮全磷的空间变化均呈“S”型趋势,7月至8月份覆膜处理玉米根系对中层氮、磷素的吸收层次较露地处理深20~40cm。全生育期全膜双垄沟播处理0~60cm土层的氮吸收比最高,处理间0~60cm土层的磷吸收比差异不显著。2.全膜双垄沟播处理促使土壤硝态氮的积累。玉米全生育期各处理0-40cm土层硝态氮含量变化显著,随着土层的加深,含量受外界的影响减弱;各处理0-200cm土层硝态氮含量总体在6月10日至7月10日最高,9月10日至10月10日最低;5月10日至8月10日各处理土壤硝态氮含量随土层加深逐渐降低,9月10日至10月10日呈波动式降低,表层与深层土壤硝态氮含量差异减小;10月10日全膜双垄沟播处理0-200cm土层硝态氮含量总体高于其他处理;而在秸秆与留茬处理中,各处理硝态氮含量相当,且变化没有规律。玉米全生育期不同深度土壤硝态氮含量变化幅度0-20cm土层最大;140-200cm土层最小。3.全膜处理和秸秆覆盖处理可显著促进植株氮、磷素的累积。作物氮、磷养分含量随生育期的延长而降低,而地上部养分累积量总体呈增加趋势。除露地平作处理外,各处理玉米氮、磷养分累积动态曲线呈“S”型,地上部氮和磷累积至成熟期达最大。玉米氮、磷养分累积高峰不同,氮素在8月5日时累积量达最大,磷直到10月5日才达最大。全膜双垄沟播处理下玉米子粒氮、磷累积量显著大于其他处理,立茬和立秆处理对玉米子粒氮、磷养分的累积没有增加效果。全膜处理氮、磷素收获指数显著高于其他处理,秸秆处理对氮、磷收获指数影响不显著;全膜处理玉米植株氮素残留较多,氮素利用效率与免耕立茬及免耕秸秆覆盖处理差异不显著,全膜处理磷素利用效率显著大于秸秆处理;覆膜处理中全膜双垄沟播处理氮、磷肥利用效率显著大于其他处理,秸秆处理中免耕+秸秆覆盖处理的氮、磷肥利用效率亦最高。更多还原

【Abstract】 Maize under a treatment of completely mulched alternating narrow and wide ridges with furrow planting (CMRF) was taken as a research object, four treatments namely flat-planting with no mulching (NM), half-mulching with flat-planting (HM), complete-mulching with flat-planting (CM) and completely mulched alternating narrow and wide ridges with furrow planting (CMRF) were designed under the treatments of film mulching and three other treatments namely no-tillage with stubble standing(NTSS), no-tillage and maize stalk standing(NTMS), no-tillage with maize stalk covering(NTMC) were also designed under the treatments of stalk covering and stubble remaining, being to study the effect of different mulching patterns on the rules of N, P nutrients uptake, accumulation and transformation and temporal-spatial variation of soil total nitrogen(TN), nitrate nitrogen(NO3-N) and total phosphorus(TP). The objective of this study was to find the rules of nutrients uptake, accumulation and transportation and the dynamics of soil nutrients, giving a scientific suggestion for extending of CMRF and inherent mechanism of its yield increasing effect. The main results were showed as follow:1. A root-friendly zone was provided under the mulching treatments for maize roots, the absorption to deeper nutrients was greatest under CMRF and the proportion of TP in 0~60cm soil layers to that in the entire 200cm soil body had no significance under different mulching patterns. Under mulching treatments, nitrogen absorption was greatest in 40~60cm layer under complete-mulching treatments from July to August, CMRF greatly affected nitrogen contents of the soil layers deeper than 110cm in the whole growth stage. TN and TP were all highest in NTMC plots under treatments of stalk covering. TP decreasing range of 20~40cm layer in whole growth stage under CMRF was 0.255g/kg, higher than the other treatments. TP contents of each treatment in 110~140cm showed a slow decreasing with no regulation with the growth stage proceeding, the decreasing range under CMRF was greatest (0.152g/kg). Spatial trends of TN and TP exhibited an“S”line, the soil layers of TN and TP absorption under mulching treatments were deeper than those of no mulching treatment by 20~40cm from July to August. The proportion of TN in 0~60cm soil layers to that in the entire 200cm soil body was highest under CMRF, while that of TP of the four treatments had no significance.2. CMRF could siginificantly promote nitrate nitrogen accumulation in soil. NO3-N content in 0-40cm layer changed significantly in whole growth stage of maize, the changes became weaker with the layer deeper. The total content in 0-200cm soil body was highest from June 10 to July 10 while lowest from September 10 to October 10, making a smaller difference between top and deep layers. The content of CMRF in 0-200cm on Oct.10 was highest. The contents under stalk covering and stubble standing treatments changed insignificantly. The range of content variation in 0-20cm in whole stages was larger than 3.438mg/kg while in 140-200cm less than 1.663 mg/kg.3. Treatments of complete mulching and maize stalk covering could siginificantly promote N, P accumulations in plant. N, P concentration was generally decreased with maize growing stage promoting, but the nutrients accumulation was increased. N, P accumulation dynamics of maize could be described by“S”curve, except that of NM treatment. N, P accumulation tendencies of maize were increased with its growing stage promoting, the highest N and P accumulations were in maturity. N maximal accumulation of maize was in August, while P in October. The N, P accumulations in kernel of CMRF were greater than other treatments, NTSS and NTMS had no significant effect on N, P accumulation in kernel of maize. N,P harvest indices of complete mulching treatments were higher than those of other treatments, stalk covering and stubble standing treatments had no significant difference in N,P harvest indices; N use efficiency among treatments of complete mulching, NTSS and NTMC had no significant difference because of much N remainder in plant under complete mulching treatments. P use efficiency of complete mulching treatments was significantly higher than that of stalk covering and stubble standing treatments; recovery of N,P fertileizer of CMRF was siginificantly higher than that of other mulching treatments, as well as NTMC higher than that of other stalk covering and stubble standing treatments.更多还原