Extensive areas have been degraded worldwide through mineral extraction. Mining class II, especially sand and pebble mining (gravel extraction), has grown significantly in Brazilian Amazonia mainly in the State of Pará. In this context, the development of suitable and efficient recovery techniques is necessary to ensure mined land restoration. The objective of this study was to evaluate the effects of different types of management and green manure methods to recover degraded soil after the mining of pebbles and sand. The experiment was implemented in the northern region of the municipality of Capitão Poço, State of Pará. The procedures we used were: a randomized block design experiment, with a 4 × 3 factorial arrangement. Four legume species were tested: Cajanus cajan (L.), Canavalia ensiformis (L.) DC, Crotolaria juncea (L.), and Mucuna pruriens (L.); in addition, three soil conditions were also tested: exposed soil, topsoil, and hydrogel. Results of the analyses showed how the root collar diameter, stem length, fertility, germination, green and dry biomass varied; the variable topsoil had better results when compared to the samples that used hydrogel and those established on exposed soil in practically all the mean comparisons for isolated factors. Besides this, C. ensiformis (L.) DC and M. pruriens (L.) showed a better development, especially when grown in soils with topsoil deposition as a reconformed substrate. From these studies we conclude that the use of this substrate is to be recommended. C. ensiformis (L.) DC and M. pruriens (L.) are also recommended for restoration.

中文翻译：

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种植豆类和土壤条件对砂石开采区恢复的影响

世界范围内，广泛的地区已经通过矿物提取而退化。采矿类II，尤其是沙子和卵石采矿（砾石提取）在巴西亚马逊州（主要在帕拉州）显着增长。在这种情况下，必须开发适当而有效的恢复技术，以确保恢复雷区。这项研究的目的是评估卵石和沙子开采后不同类型的管理方法和绿肥方法对恢复退化土壤的影响。该实验是在帕拉州CapitãoPoço市北部地区进行的。我们使用的过程是：4×3析因排列的随机块设计实验。测试了四种豆科植物：Cajanus cajan（L。），Canavalia ensiformis（L.）DC，Crotolaria juncea（L.）和Mucuna pruriens（L.）; 此外，还测试了三种土壤条件：裸露的土壤，表土和水凝胶。分析结果表明，根领直径，茎长，繁殖力，发芽，绿色和干燥生物量如何变化；与使用水凝胶的样品和在裸露土壤上建立的样品相比，在几乎所有隔离因素的均值比较中，可变表土的效果更好。除此之外，C。ensiformis（L.）DC和M. pruriens（L.）表现出更好的发育，尤其是在土壤中生长的表土沉积为重新整合的基质时尤其如此。从这些研究中，我们得出结论，建议使用这种基材。还建议使用恩氏梭状芽胞杆菌（L.）DC和瘙痒M. pruriens（L。）进行修复。