Forest conversion to pasture affects soil phosphorus dynamics and nutritional status in Brazilian Amazon
Forest conversion to pasture affects soil phosphorus dynamics and nutritional status in Brazilian Amazon
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DOI：
10.1016/j.still.2019.104330
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发表时间：
2019-11
影响因子：
6.5
通讯作者：
A. Soltangheisi;M. T. Moraes;M. Cherubin;D. O. Alvarez;Leandro Fonseca de Souza;W. Bieluczyk;D. Navroski;A. P. Teles;P. Pavinato;L. Martinelli;S. Tsai;P. Camargo
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文献类型：
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作者：
A. Soltangheisi;M. T. Moraes;M. Cherubin;D. O. Alvarez;Leandro Fonseca de Souza;W. Bieluczyk;D. Navroski;A. P. Teles;P. Pavinato;L. Martinelli;S. Tsai;P. Camargo
了解土地利用变化对土壤磷素转化的影响，并确定影响土壤磷素营养状况的因素，对于更好地管理土壤，尤其是亚马逊地区的土壤磷素具有重要意义。我们调查了不同的P组分和它们的转换，在不同的土地利用（原始森林和牧场）和土壤质地（粘土和桑迪）在亚马逊河流域Oxisols通径分析。除磷素分级外，还研究了磷酸酶活性及其与土壤碳（C）/有机磷（Po）比值的相关性，以探讨磷酸酶活性与土壤磷素营养状况的关系。经过15年的森林砍伐和燃烧，牧草中的全P达到森林水平在亚马逊河流域的土壤，无论土壤质地。通径分析表明，退耕还林降低了土壤磷库对阴离子交换树脂提取缓冲磷贡献的多样性。然而，Po占四分之一的全P在我们的网站，它起着重要的作用，作为植物有效P的来源，并提供了更多的草地相比，森林。我们的研究结果从磷分馏和C：PO比显示，亚马逊草原和森林是不缺磷。我们还表明，随着C：Po比的增加，植物有效磷含量变得更加依赖于磷矿化。土壤酸性磷酸酶活性可作为评价土壤磷素营养状况的指标，但其变化范围因土地利用方式而异。
Understanding the pathways of soil phosphorus (P) transformations and determining the factors related to P nutritional status of soils when land use changes is critical for a better management, especially in Amazon region. We investigated different P fractions and their transformations in different land uses (primary forest and pasture) and soil textures (clayey and sandy) in Amazonian Oxisols using path analysis. Besides P fractionation, phosphatase activity and its correlation with soil carbon (C):organic P (Po) ratio was evaluated to correlate it with soil P nutritional status. After 15 years from forest slashing and burning, total P in pasture reaches to the forest levels in Amazonian soils, regardless of soil texture. Path analysis showed that land use conversion from forest to pasture decreased the diversity of the contribution of P pools to buffer P extracted by anion exchange resin. However, Po accounted for one-fourth of total P in our sites, it plays an important role as source of plant available P and contributed more in pasture compared to forest. Our results from P fractionation and C:Po ratio revealed that Amazonian pastures and forests are not P deficient. We also showed that with increasing C:Po ratio, plant-available P content became more dependent on P mineralization. Soil acid phosphatase activity can be used as an indicator for evaluating soil P nutritional status; however, its range changes according to the land use.