Effect of increasing densities of Urochloa brizantha cv. Marandu on Eucalyptus urograndis initial development in silvopastoral system
Effect of increasing densities of Urochloa brizantha cv. Marandu on Eucalyptus urograndis initial development in silvopastoral system
复制标题
增加Urochloa brizantha cv. 密度的效果。
DOI：
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发表时间：
2019
影响因子：
1.5
通讯作者：
R. Paula
中科院分区：
文献类型：
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作者：
Michel Anderson Almeida Colmanetti;A. L. Bacha;Pedro Luis Costa Aguiar Alves;R. Paula
在人工林系统中，桉树幼苗与其它树种共存会导致桉树幼苗的生长下降，特别是在桉树早期发育阶段。因此，研究牧草种类对桉树生长的影响，可以为桉树的合理管理提供重要信息，以获得系统的最大收益。本研究的目的是评估增加密度的效果。尾巨桉早期发育中的马兰杜。在20 L的盆中，在开放和半控制的区域中，在桉树种植后的90天期间进行了试验。采用完全随机设计，重复4次，采用6 × 7析因系统，即6个评价期和7个U. brizantha：0（对照）、22、33、44、67、89和111株m-2。每两周测定一次桉树树高、茎粗和叶绿素荧光值（Fv/Fm）。试验结束时，测定了桉树的净同化率、气孔导度和蒸腾速率，并测定了桉树和乌桕的干物质含量。brizantha（leaves）.在与111株m-2植物共存的情况下，与对照相比，桉树的总干物质减少了63.9%，叶面积减少了72.7%。从22株m-2的密度来看，U. brizantha对E.大尾龙高达8株m-2，桉树高度和茎直径的减少不超过5%。
In silvopasture system, the coexistence of eucalyptus seedlings with other species may result in growth reduction, especially during eucalyptus early development. Therefore, studies elucidating how forage species affect the eucalyptus growth can provide important information for their rational management aiming to obtain the maximum gain of the system. The aim of this work was to evaluate the effect of increasing densities of Urochloa brizantha cv. Marandu in the early development of Eucalyptus urograndis. An experiment was conducted in 20 L pots, in an open and semi-controlled area, during 90 days after planting of eucalyptus. A completely randomized design with four replications was used, in a 6 × 7 factorial system, meaning six evaluation periods and seven densities of U. brizantha: 0 (control), 22, 33, 44, 67, 89 and 111 plants m−2. Fortnightly, eucalyptus height, stem diameter and chlorophyll fluorescence (Fv/Fm) were evaluated. At the end of experimental period, the net assimilation rate, stomatal conductance and transpiration rate of eucalyptus plants were determined, in addition to the dry matter of eucalyptus (leaves and stem) and U. brizantha (leaves). In coexistence with 111 plants m−2, eucalyptus had reduction of 63.9% on total dry matter and 72.7% on leaf area, compared to the control. From the density of 22 plants m−2, U. brizantha negatively interfere significantly the growth of E. urograndis. Up to 8 plants m−2 there are no reductions greater than 5% in eucalyptus height and stem diameter.