【作者】 肖质净；

【导师】 王殿武；

【作者基本信息】 沈阳农业大学 ， 水资源与农业节水， 2014， 博士

【摘要】 辽西风沙半干旱区域常年干旱少雨,无效降雨较多,降水利用率和水分生产利用效率不高,耕作区风蚀沙化严重,导致作物粮食产量常年不稳。为了提高该地区农业对降水资源利用率,改善作物的生长环境,提高作物产量,本研究在2007-2009年,设计了垄上覆膜沟内种植(T1)、垄上覆膜沟内覆膜种植(T2)和垄上覆膜沟内覆盖秸秆种植(T3)3种微集水处理模式,并以传统平作种植模式(CK)作为对照试验进行优选研究；在2012-2013年对微集水种植技术进行了优化设计,又增设了全膜双垄覆盖种植(T4)处理模式。通过研究上述四种微集水种植技术对土壤水分与温度、作物生长发育和产量、以及土壤养分变化的影响,分析评价了上述四种微集水种植技术的优劣性,以期能够选出最适合辽西风沙半干旱农业区的微集水种植模式。为更加全面的评价微集水技术的种植效果,优选出最适合北方半干旱地区的微集水种植技术,本研究引入了农田实际蒸散量,作物需水量等参数,并利用FLUENT数据软件模拟了降水在土壤中的渗透情况,从而能更加全面的分析评价四种微集水技术的蓄水保墒效果,及其对作物生长发育的影响。研究结果如下：(1)相对于传统平作种植模式,微集水模式具有明显的蓄水保墒效果。作物生育期内,T3和T4处理在0-160cm土层的蓄水量最。(2)通过FLUENT软件绘制了各处理的流速等值云图,并利用流速等值云图的分析降水在土壤中下渗情况。相比CK处理,微集水种植模式下,降水在土壤中下渗速度更快且下渗速度变化缓慢,利用MATLAB软件拟合出最快的下渗渗流速度方程计算出各处理模式的水分下渗速度。T4处理降水下渗平均速度最快,更有利于降水储存到土层深处。(3)作物生育期内,微集水种植的农田实际蒸散量、农用作物需水量小于CK。其中T3和T4处理的农田实际蒸散量、农田作物需水量最小(4)微集水种植的覆膜处理可明显提高土壤表层温度,覆盖面积最大的T4处理增温效应最为明显。而T3处理由于蓄水带覆盖秸秆对土壤温度增加具有一定的负效应,土壤表层温度相对较低。(5)不同处理对玉米出苗率影响不大,而对玉米出苗时间有影响。相比CK处理,T1、T2和T4处理的出苗时间会提前,其中T4处理出苗时间最短；T3处理出苗时间会有一定延迟,出苗时间相对较长。(6)相对于CK处理,T4处理植株生长最好,各生育阶段玉米株高、叶面积、干物质积累量最大；T3处理植株在前期生长缓慢,导致各生育指标小于CK处理,到了生育后期,生长开始加速,超过CK处理。研究还发现,T3处理容易受低温气候影响,会使得作物生长始终迟缓,影响作物生长和发育。在生育前期,覆膜条件会使作物生长加快,T1、T2和T4叶绿素含量高于CK处理；但是到了生育后期,T1、T2和T4处理的植株会出现早衰现象,叶绿素含量在生育后期提前下降,而CK和T3处理没有出现这种现象。(7)微集水处理的植株根系平均直径、总根长、总根表面积、总根体积、根尖数、分叉数、根尖分叉数、根系干重较CK处理都有显著的增加,其中T4处理各参数最高。(8)总体上微集水种植模式中玉米的各项产量指标均优于传统模式,微集水处理的玉米穗长、穗粗、行粒数都高于CK处理。与传统种植相比,微集水种植都能不同程度增加玉米的作物产量,并达到显著水平。但T3处理的作物生长易受低温气候影响,在2012年,受早春低温气候影响,T3处理玉米产量显著低于其它微集水处理；而在2012-2013年,经过优化的T4处理作物产量最好,高于其它微集水处理,且水分利用效率提高最多。(9)在玉米生育期内,T4处理植株对土壤养分吸收最好,土壤速效养分含量要低于其它微集水处理。微集水种植条件下,玉米籽粒产量养分利用效率高于CK,其中T4处理表现最好。综上所述,四种微集水种植模式中,T4处理(全膜双垄覆盖种植模式)为本研究优选出的最佳模式。更多还原

【Abstract】 The Sand and Wind Semi-Arid Zones in the western part of Liaoning Province has series of characteristics performing as droughts, lack of precipitation throughout the year, more ineffective rainfalls, low efficiencies of precipitation utilization and water productive, severed water and soil erosion in the farmland, which result in the disproportionate and unstable production of grain crops. For increasing the Water Utilization Efficiency (abbreviated as WUE as follows) of the proposed agricultural zone, enhancing the developing environment of the grain crop, consequently, raising the production of grain crops, this study was designed from2007to2009as three patterns:ridge film mulching and furrow seeding (T1); ridge and furrow film (T2); groove ridge mulch film and ridge ditch straw mulching cultivation (T3), which are subsidiary of Micro-Water Catchment Patterns. Simultaneously, convention planting pattern was employed to compare for the optimization study. In the duration of2012to2013,the Micro-Water Catchment Patterns were optimized and updated, which added another pattern-round film mulching double-ridge pattern (T4). This research is based upon abovementioned four subsidiary patterns of Micro-Water Catchment Patterns, to study the effects of Micro-Water Catchments Patterns on the soil moisture, temperature, plant growth, plant development, plant yield and soil nutrient variation, thereby to analyze the advantages and disadvantages of Micro-Water Catchment Patterns. Thus, discovering the most suitable and decent pattern in the sand and wind semi-arid agricultural zone, western Liaoning.For a complete and thorough evaluation of the result and effect from Micro-Water Catchment Patterns, discovering the most suitable and decent pattern in semi-arid zone of the North China, this study uses some advanced parameters such as evapotranspiration, water demand, and utilizes FLUENT software to simulate the infiltration of precipitation in the soil, in order to obtain the more comprehensive analyses and evaluations. The research results are summarized as follows:(1) The Micro-Water Catchment Patterns have significant effect on soil moisture conservation compared with the convention planting pattern. The experiment demonstrates that T3and T4perform the best under0-160cm soil layer.(2) By analyzing the convection velocity contours depicted by FLUENT, the infiltration of precipitation in the soil is more rapidly and the infiltration velocity is relatively low, which is based on the comparison with CK. By employing MATLAB for fitting the function versus the fastest velocity of infiltration, computing the velocity of each pattern, the result shows that T4has the fastest average infiltration velocity, meaning that T4is favorable for the storage of precipitation in the deep layer of soil.(3) In the duration of crop growth period, the evapotranspiration and water demand in the Micro-Water Catchment Pattern is much lower than CK pattern, T3and T4has the lowest value.(4) The soil surface temperature is apparently increased by adopting film mulching from Micro-Water Catchment Pattern. T4has the biggest covered area, which is accordingly has the most significant effect of temperature increase, whereas T3pattern has some certain of negative effect which is attributed to the use of straw. Thus, T3has the lowest temperature in the soil surface.(5) Different patterns have no obviously effect on emergency rate of maize, while work apparently on the emergency time. T1, T2and T4are ahead of the normal emergency time, and T4has the shortest time, T3has some certain delay, by comparing with CK pattern.(6) In contrast with CK pattern, T4grows with the best parameters(the plant height, leaf area, dry matter accumulation in different stages); T3grows slowly in the early stage, which results in the lower value of parameters versus CK, whilst in the anaphase, the pulse growth leads T3to overpass CK. Further study explores that T3is easily affected by low temperature, and then postpone the growth of crops. In the early stage, film mulching may accelerate the growth of crops; T1, T2and T4have higher chlorophyll content than CK. However, at the anaphase, T1, T2and T4perform as premature senility, the chlorophyll content decrease in the later period, while T3performs as normal.(7) The planting parameters (average diameter, general root length, general root volume, root tip, bifurcate, bifurcate of root tip, root dry weight and canopy dry weight) has significant increase by employing the Micro-Water Catchment Pattern compared with CK, T4has the highest values in all the parameters.(8) The Micro-Water Catchment Pattern has no significant effect in corncob row, bare tip and pachyrachis, while the value of ear length, ear width and row grains are higher than CK. Apart from2008which was the high flow year, the thousand seed weight of maize in Micro-Water Pattern in the other years were heavier than CK, T4was the heaviest. Micro-Water Catchment Patterns may increase the yield of maize in different extent, significantly, by comparing with convention planting pattern. From2007to2009, T2and T3had the highest increase yield, but T3was affected by the low temperature. In2012, T3maize yield was obviously lower than other patterns. During2012to2013, the optimized T4had the highest yield, much higher than other patterns, and had also the highest WUE.(9) In the durations of tasseling stage and mature stage of maize, the average readily available nutrient of soil in T4pattern is much lower than others. In Micro-Water Catchment Patterns, the maize grain yield’s nutrient utilization efficiency is higher than CK, T4pattern perform as the best.The study illustrates that T4pattern (round film mulching double-ridge pattern of Micro-Water Catchment Patterns) is the most optimized and the best pattern in accordance with this Micro-Water Catchment Patterns study.更多还原