Defining competition vectors in a temperate alley cropping system in the midwestern USA - 2. Competition for water
Defining competition vectors in a temperate alley cropping system in the midwestern USA - 2. Competition for water
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DOI：
10.1023/a:1006289322392
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发表时间：
2000-02-01
影响因子：
2.2
通讯作者：
Biehle, DJ
中科院分区：
文献类型：
--
作者：
Jose, S;Gillespie, AR;Biehle, DJ
在美国东部玉米带的一种巷道种植制度下进行了一项研究，目的是量化黑核桃(Juglans ngra L.)和红栎树(Quercus rubra L.)和玉米(Zea Mays L.)研究了土壤水分、树木和玉米的根系形态、树木和玉米的吸水率以及玉米叶面积扩展在三个处理中的时空变化：“屏障”(分隔玉米和树根的聚乙烯根屏障)、“沟”(不设置聚乙烯屏障的沟渠)和“无屏障”(对照)。在黑核桃和红栎巷种植系统中都观察到了土壤水分的显著时间变化。与“无障碍”处理相比，“障碍”和“沟渠”处理导致“玉米巷”的土壤水分较高，而“树行”的土壤水分较低。玉米对水分的吸收在“屏障”处理高于“无屏障”处理。然而，“无障碍”处理的树木吸水率高于“障碍”处理，因为树根利用来自“玉米小巷”的水分。在“无障碍”处理中，水分胁迫对玉米叶面积产生了负面影响。对生根模式的量化表明，玉米和树木的根系集中在水分波动最大的30 cm表层。“障碍”和“沟渠”处理成功地消除了树木和玉米之间的地下根竞争，并导致了比“无障碍”处理更大的叶面积和更高的粮食产量。因此，对水的竞争，而不是对光的竞争，似乎是定义这种巷道种植制度的生产力和可持续性的关键。
A study was carried out in an alley cropping system in the Eastern Maize Belt of the United States with the objective of quantifying the competition for water between trees black walnut (Juglans nigra L.) and red oak (Quercus rubra L.) and maize (Zea mays L.). Spatial and temporal variation in soil moisture, tree and maize rooting patterns, tree and maize water uptake, and maize leaf area expansion were determined in three treatments; 'barrier' (polyethylene root barriers separating maize and tree roots), 'trench' (trenching without a polyethylene barrier), and 'no barrier' (control). Significant temporal variation in soil moisture was observed in both black walnut and red oak alley cropping systems. The 'barrier' and 'trench' treatments resulted in higher soil moisture in the 'maize alley' and lower soil moisture in the 'tree row' than the 'no barrier' treatment. Uptake of water by maize was higher in the 'barrier' than the 'no barrier' treatment. However, tree water uptake was higher in the 'no barrier' treatment than in the 'barrier' treatment because tree roots utilized water from the 'maize alley'. Maize leaf area was negatively impacted by water stress in the 'no barrier' treatment. Quantification of rooting patterns revealed that maize and tree roots were concentrated in the top 30 cm soil layer where water fluctuations were greatest. The 'barrier' and 'trench' treatments successfully eliminated the belowground root competition between trees and maize and resulted in greater leaf area and higher grain yields than the 'no barrier' treatment. Thus, competition for water rather than competition for light seems to be critical in defining the productivity and sustainability of this alley cropping system.