Root distribution and water use in coffee shaded with Tabebuia rosea Bertol. and Simarouba glauca DC. compared to full sun coffee in sub-optimal environmental conditions
Root distribution and water use in coffee shaded with Tabebuia rosea Bertol. and Simarouba glauca DC. compared to full sun coffee in sub-optimal environmental conditions
复制标题
用 Tabebuia Rosea Bertol 遮荫的咖啡中的根分布和水利用。
作者：
M. P. Padovan;M. P. Padovan;V. Cortez;L. Navarrete;E. Navarrete;A. Deffner;L. Centeno;R. Munguia;M. Barrios;J. S. Vílchez;C. Vega;A. N. Costa;R. Brook;B. Rapidel;B. Rapidel
在尼加拉瓜的阿拉比卡咖啡农林复合系统中，发现了优化资源开发的根际生态位分化。比较了未遮荫(FS)和遮荫(AFS)咖啡与两种以前未经测试的热带木材树种(落叶玫瑰花椒Tabebuia roSea Bertol)的生根行为。和常绿西马鲁巴Siluca DC.)主要的安地酚有一层压实的土层(石榴石)。这项研究是在尼加拉瓜咖啡种植的次优环境条件下进行的(455万平方英里，年平均气温27摄氏度，降雨量1300毫米/年，旱季6个月)。在AFS和FS中分别挖了12条和5条深达200 cm的壕沟。在两个垂直的土面上计算每单位面积的根数。在两年多的时间里，利用45个反射仪在不同土层中连续测量了体积水。在深度、厚度和物理结构上差异很大。咖啡细根比树根丰富，主要集中在较浅层(0~80 cm)，而树根在100 cm以下繁殖较多。在100 cm以下，灰树根系的密度要大于玫瑰红豆杉。在FS和T.roSea下，咖啡根数没有显著差异，但在灰树附近，咖啡根数较高。2012年和2014年是轻度旱季，全剖面土壤水分含量在旱季和旱季相似，但在2013年严重旱期，旱季旱地土壤容积性和吸水率均低于旱地。这表明，在AFS中进行更多的土壤勘探的正常优势被取消了，这可能是因为深深生根的树木持续吸收水分，而FS仍然有可用的水。
Root niche differentiation for optimal exploitation of resources was found in an arabica coffee agroforestry system in Nicaragua. Rooting behavior was compared in both unshaded (FS) and shaded (AFS) coffee combined with two previously untested tropical timber species (deciduous Tabebuia rosea Bertol. and evergreen Simarouba glauca DC.). The predominant andisol possesses a compacted soil layer (talpetate). The study was conducted in sub-optimal environmental conditions for coffee cultivation (455 m.a.s.l., annual mean 27 °C, 1300 mm rainfall/year, 6 months dry season) in Nicaragua. Twelve and five trenches 200 cm deep were dug in AFS and FS respectively. Roots per unit area were counted on two perpendicular soil faces. Volumetric water was measured continuously over 2 years by using 45 reflectometers in different soil layers. The talpetate varied greatly in depth, thickness and physical structure. Coffee fine roots were more abundant than tree roots and were concentrated in the shallower strata (0–80 cm) whilst tree roots proliferated more below 100 cm. The S. glauca root system was denser below 100 cm than T. rosea root system. There was no meaningful difference in coffee root counts in FS and under T. rosea, but coffee root counts were higher near S. glauca trees. 2012 and 2014 had mild dry seasons and whole profile soil water content was similar in FS and AFS, but in the 2013 severe dry period volumetric water and water uptake were lower in AFS than in FS. This indicates that the normal advantage of greater soil exploration in AFS was cancelled presumably due to continued water uptake by deep rooting trees whereas the FS still had available water.