【作者】 齐万海；

【导师】 柴强；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2009， 硕士

【摘要】 小麦间作(∥)玉米是我国西北地区,特别是甘肃一熟灌区普遍应用的高产种植模式,但是受水资源紧缺的严重制约,该区间作应用面临重大挑战,间作节水理论和技术研究亟待深入。本研究通过大田试验,结合微型蒸渗仪(Micro-Lysimeters,MLS)测定棵间蒸发和根系分隔方法,研究了隔根对绿洲灌区小麦∥玉米的产量、水分利用效率、根系时空分布和耗水特性的影响,并对根系时空分布与耗水特性的关系进行了探讨。主要结论如下:1、与单作相比,小麦∥玉米具有提高土地利用效率和作物水分利用效率的作用,隔根影响间作产量和水分利用效率的提高间作可提高土地利用效率,不隔根小麦间作玉米(W∥C)、塑料布隔根小麦间作玉米(PW∥C)和尼龙网隔根小麦间作玉米(NW∥C)的土地当量比分别达到了1.46、1.20%和1.39。W∥C、PW∥C、NW∥C与单作小麦和单作玉米相比,产量分别提高了76.2%、46.2%、67.9%和25.4%、4.1%、19.5%,隔根对小麦产量的影响大于玉米。塑料布隔根显著降低了小麦间作玉米的产量,PW∥C与W∥C、NW∥C相比,产量分别下降了20.5%、14.8%,说明根间作用对小麦∥玉米的贡献份额为17.0%,而通过根系的空间交错产生的贡献份额为4.7%。W∥C、PW∥C、NW∥C的水分利用效率分别比单作小麦、单作玉米水分利用效率的加权平均值高51.90%、25.94%、43.04%,W∥C的水分利用效率分别较PW∥C、NW∥C高17.1%和5.8%。隔根降低了间作的水分利用效率,根间作用对小麦∥玉米水分利用效率的贡献份额为17.1%,而通过根系交错产生的贡献份额为5.8%。2、种植模式影响小麦、玉米全生育期的耗水量,隔根对小麦∥玉米总耗水量影响较小、对棵间蒸发量的影响较大与单作耗水量的加权平均相比,W∥C、PW∥C、NW∥C的耗水量分别增大了3.24%、3.00%、1.81%,三个间作之间耗水量差异不显著。W∥C、PW∥C、NW∥C的总棵间蒸发分别比单作总棵间蒸发加权平均值高44.1%、31.3%、41.0%,W∥C棵间蒸发PW∥C和NW∥C分别高8.9%和2.2%,根间作用对小麦∥玉米总棵间蒸发量的影响为8.9%,而通过根系交错产生的影响为2.2%。单作小麦、单作玉米及三个间作处理总棵间蒸发量占耗水总量的比重分别为18.2%、12.2%、22.0%、20.0%、21.2%,即间作增大了棵间蒸发所占份额。3、间作影响小麦、玉米根系的时空分布,并在不同时期形成了对土壤空间的叠加利用小麦、玉米共生期内,W∥C中的小麦根系垂直分布范围小于单作小麦,W和W∥C小麦根重密度(g/500cm~3土壤)为0.02的等值线分别在70cm和60cm左右;PW∥C、NW∥C中的小麦根重密度为0.02的等值线分别在80cm和75cm,高于单作。W∥C横向分布占据并利用两间作作物地下部的大部分空间,根重密度为0.02的根系侧向进入玉米根区20-40cm,而玉米根系只利用其根系范围较小的空间。当玉米进入灌浆期(小麦收获后)W∥C玉米则占据并利用两间作作物的大部分地下部空间,在纵向和横向扩大了根系养分吸收的有效空间,其根系在横向占据了小麦根区的整个剖面。隔根方式在不同程度上影响了小麦玉米的根重密度以及下扎深度,不隔根处理的小麦根重密度高于隔根处理的,而在两个隔根处理之间尼龙网隔根的根重密度要高于塑料布隔根,根间作用对小麦∥玉米根系干重的贡献份额为36.6%,而通过根系交错产生的贡献份额为28.5%。根系干重与WUE呈显著正相关。小麦20-40cm根系干重与产量成显著正相关。更多还原

【Abstract】 Wheat corn intercropping is one of a widely used highyield multiple cropping pattern in Hexi Oasis Area of Gansu Province.However,being the serious shortage of natural water resources,the application of intercropping is decreasing continuously in recent years,and the arable land productivity is decreasing simultaneously,so opening up high efficient water-saving theory and technology for intercropping has become big chanllenge in multiple cropping research area.In this study,a field experiment was carried out in typical oasis area,in order to investigate the effect of root interaction on the yield and water use efficiency(WUE) of wheat corn intercropping system.Three kinds of root separation were cobined in the intercropping systems,and the Micro-Lysimeters were used to measure the soil evaporation.The relationships between root distribution characteristics,soil water content, leaf area index and WUE of crops was discussed finally.The main results showed as following:1.Compared with single cropping systems,wheat-corn intercropping is promoted theland equivalent ratio and the water use efficiency.and roots iteraction plays an important role in improvind the yield and WUE of intercropping.separation makes influence on the improvement of intercropping yield performance and WUE,and intercropping is able to promote the land-use efficiency.LER of Non-root-separation(W//C),wheat corn intercropping that root separated by plastic film(PW/C),wheat corn intercropping that root separated by nylon(NW/C) are 1.46%,1.20%and 1.39%.Compared with single-planted wheat and single-planted corn,the yield performances of W//C,PW//C,NW//C have been raised by 76.2%,46.2%,7.9%,and 25.4%,4.1%,19.5%, which shows that the influence of root separation is greater on wheat yield performance than that of corn. PW//C remarkably lows the W//C intercropping.PW//C compared between W//C、NW//C,the yield performance lows as 20.5%,14.8%,which demonstrates that the contributive proportion of root affection of W//C is 17.0%,while that of spatial root intersection is 4.7%.WUE of W//C,PW//C,NW//C are higher than the weighted average of single planted wheat,and single planted corn,performed as 51.90%,25.94%, 43.04%.WUE of W//C compared with PW//C,NW//C is higher by 17.1%,5.8%.Root separation lows WUE of intercropping.The contributive proportion that root intersection performs on WUE of W//C is 17.1%,while that of spatial root intersection is 5.8%.2.The planting model makes influence on the water consumption of wheat and corn in their whole growth period.Root separation makes a smaller influence on the water consumption of wheat corn intercropping,a greater influence on evapotranspiration.Compared with the weighted average of sole wheat and corn WUE,WUE of W//C,PW//C,NW//C are increased seperately by 3.24%,3.00%,1.81%.And the divergence of the three dates is not obvious.The total evapotranspiration of W//C,PW//C,NW//C is higher than that of the weighted average of the single planted evapotranspiration as 44.1%,31.3%,41.0%.The evapotranspiration of W//C is higher than that of PW//C and NW//C,by 8.9%and 2.2%.The influence of root affection on the evapotranspiration of W//C is 8.9%,while which of spatial root intersection is 2.2%.The proportion of WUE of the evapotranspiration of both single planted wheat and corn,and the three kinds of intercropping is 18.2%,12.2%,22.0%,20.0%, 21.2%.In a word,intercropping enlarges the proportion of evapotranspiration.3.Intercropping makes influence on the temporal and spatial distribution of the root systems of wheat and corn,and makes a superposition of the use of underground soil space in different periods.During the period of W//C commensalism,in W//C,the vertical distribution area of wheat root is smaller than that of the single planted wheat.The density of W and W//C root weight(g/500cm3) is 0.02,and the equivalence lines are about 70cm and 60cm.The density of PW//C and NW//C root weight(g/500cm3) is 0.02,and the equivalence lines are about 80cm and 75cm,which is higher than that of the single plangtation.The sidelong distribution of W//C occupies and makes use of most of the space of the underground part of the two intercropping plants,and the root system of 0.02 in root weight density grow crosswise into the root system of corn by 20-40cm.The corn root system only occupies a small part of the space.When corn has been into the filling stage,corn in W//C occupies and makes use of underground soil space,and enlarges its effective space of absorbing the nutrients both vertically and laterally,and its root system occupies the whole profile of the wheat root laterally.In various conditions,root separation methods make influences on the root weight density and downward depth of wheat.Non-root-separation root weight density is higher than that of root separation.Between the two different separations,root weight density in NW//C is higher than that of PW//C,and the contributive proportion that root intersection makes on W//C root dry weight is 36.6%,while it is 28.5%of spatial root intersection.Root dry weight makes an obvious positive relevance with WUE.The root dry weight of wheat of 20-40cm makes an obvious positive relevance with the yield performance.更多还原