Mapping rootable depth and root zone plant-available water holding capacity of the soil of sub-Saharan Africa.
Mapping rootable depth and root zone plant-available water holding capacity of the soil of sub-Saharan Africa.
复制标题
DOI：
10.1016/j.geoderma.2018.02.046
复制
发表时间：
2018-08-15
期刊：
影响因子：
6.1
通讯作者：
Cassman KG
中科院分区：
文献类型：
--
作者：
Leenaars JGB;Claessens L;Heuvelink GBM;Hengl T;Ruiperez González M;van Bussel LGJ;Guilpart N;Yang H;Cassman KG
在作物生产中，土壤根区植物有效持水量（RZ-PAWHC）对作物生长和产量对管理投入（如改良种子和肥料）的反应有很大影响。然而，撒哈拉以南非洲缺乏这一参数的数据。这项研究产生了第一个空间上明确的，连贯的和完整的地图的根深和RZ-PAWHC的土壤在SSA。我们从28，000个来自SSA的土壤剖面中汇编了地理参考数据，这些数据被用作数字土壤制图（DSM）技术的输入，以生成SSA的土壤属性图。基于这些土壤特性，我们开发和参数化（pedotransfer）功能，规则和标准，以评估土壤持水能力在田间容量和萎蔫点，土壤细土分数从粗碎片的内容，玉米，土壤生根能力（相对于阈值）和生根深度。这些次生土壤特性的地图，使用的主要土壤特性图作为输入的评价规则和结果进行汇总的可生根的深度，以获得一个地图的RZ-PAWHC，空间分辨率为1平方公里。SSA的平均RZ-PAWHC为74 mm，相关的平均根区深度为96 cm。两者之间的Pearson相关系数为0.95。RZ-PAWHC被证明最受可生根深度的限制，但对田间持水量的定义也高度敏感。由于土壤条件限制了根区深度，玉米潜在可生根的SSA土壤总体积减少了三分之一（超过10 500立方公里）。其中，4800 km 3是由于有限的曝气深度，这是最严重的限制因素方面的范围（平方公里），和2500 km 3由于碱，这是最严重的限制程度（深度厘米）。土壤至基岩的深度减少了2 500立方公里的可生根土壤体积、600立方公里的铝毒性、120立方公里的孔隙度和20立方公里的碱度。由于缺乏关于可生根性和可生根深度的数据，因此RZ-PAWHC的可生根深度图的准确性无法定量验证，但主要土壤性质图的准确性有限。该方法框架是健全的，并已投入运作，因此，随着获得更多数据，地图可以很容易地更新。可生根深度和根区植物有效持水量为SSA绘制的平均可生根深度为96厘米，相关的RZ-PAWHC为74毫米。由于限制性通气、盐碱、基岩，可生根体积减少了三分之一，由于缺乏可生根性数据，无法验证可生根深度图的准确性。强大的框架;地图可以随着额外数据的可用而更新。
In rainfed crop production, root zone plant-available water holding capacity (RZ-PAWHC) of the soil has a large influence on crop growth and the yield response to management inputs such as improved seeds and fertilisers. However, data are lacking for this parameter in sub-Saharan Africa (SSA). This study produced the first spatially explicit, coherent and complete maps of the rootable depth and RZ-PAWHC of soil in SSA. We compiled geo-referenced data from 28,000 soil profiles from SSA, which were used as input for digital soil mapping (DSM) techniques to produce soil property maps of SSA. Based on these soil properties, we developed and parameterised (pedotransfer) functions, rules and criteria to evaluate soil water retention at field capacity and wilting point, the soil fine earth fraction from coarse fragments content and, for maize, the soil rootability (relative to threshold values) and rootable depth. Maps of these secondary soil properties were derived using the primary soil property maps as input for the evaluation rules and the results were aggregated over the rootable depth to obtain a map of RZ-PAWHC, with a spatial resolution of 1 km2. The mean RZ-PAWHC for SSA is 74 mm and the associated average root zone depth is 96 cm. Pearson correlation between the two is 0.95. RZ-PAWHC proves most limited by the rootable depth but is also highly sensitive to the definition of field capacity. The total soil volume of SSA potentially rootable by maize is reduced by one third (over 10,500 km3) due to soil conditions restricting root zone depth. Of these, 4800 km3 are due to limited depth of aeration, which is the factor most severely limiting in terms of extent (km2), and 2500 km3 due to sodicity which is most severely limiting in terms of degree (depth in cm). Depth of soil to bedrock reduces the rootable soil volume by 2500 km3, aluminium toxicity by 600 km3, porosity by 120 km3 and alkalinity by 20 km3. The accuracy of the map of rootable depth and thus of RZ-PAWHC could not be validated quantitatively due to absent data on rootability and rootable depth but is limited by the accuracy of the primary soil property maps. The methodological framework is robust and has been operationalised such that the maps can easily be updated as additional data become available. Rootable depth & root zone plant-available water holding capacity mapped for SSA Average rootable depth is 96 cm and associated RZ-PAWHC is 74 mm. Rootable volume reduced by a third due to restrictive aeration, sodicity, bedrock Accuracy rootable depth map cannot be validated due to lack of data on rootability. Robust framework; maps can be updated as extra data become available.
登录
查看更多内容
影响因子：
56.9
作者：
Fan, Y.;Li, H.;Miguez-Macho, G.
通讯作者：
Miguez-Macho, G.
影响因子：
--
作者：
BRENES, E;PEARSON, RW
通讯作者：
PEARSON, RW
影响因子：
8.3
作者：
Gijsman, Arjan J.;Thornton, Philip K.;Hoogenboom, Gerrit
通讯作者：
Hoogenboom, Gerrit
影响因子：
6.6
作者：
DEWIT, CT
通讯作者：
DEWIT, CT
影响因子：
6.9
作者：
Bengough, AG;Bransby, MF;Valentine, TA
通讯作者：
Valentine, TA