Use of indicators and pore volume-function characteristics to quantify soil physical quality
Use of indicators and pore volume-function characteristics to quantify soil physical quality
复制标题
DOI：
10.1016/j.geoderma.2009.06.009
复制
发表时间：
2009-09
期刊：
影响因子：
6.1
通讯作者：
W. Reynolds;C. Drury;C. Tan;C. A. Fox;X. Yang
中科院分区：
文献类型：
--
作者：
W. Reynolds;C. Drury;C. Tan;C. A. Fox;X. Yang
Dexter“S值”（Sgi）是一个很有前途的新的土壤物理质量指标（SPQ），但它并没有很好地与已建立的指标，如相对田间持水量（RFC），植物有效持水量（PAWC），空气容量（AC），大孔隙度（PMAC），容重（BD），有机碳含量（OC）和结构稳定性指数（SI）进行比较。此外，所有SPQ指标都是孔隙体积和/或孔隙功能的直接或间接表达，但尚未确定最佳孔隙体积-功能特征。本研究的目的是：i）比较Sgito的其他七个指标的范围内的刚性中度膨胀土和人工多孔介质; ii）使用的指标，提出一个最佳的孔隙体积分布和土壤水分释放曲线;和iii）评估SPQ堆肥改良土壤使用的指标，孔隙体积分布和水分释放曲线。这些指标是在实验室中对从13种土壤管理组合中收集的完整土壤芯和抓取样本进行测量的。土壤质地包括粘壤土、桑迪粘壤土、壤土、桑迪壤土和砂土;管理包括处女地、免耕种植和犁板耕作。还包括两个人工介质组成的玻璃珠和建筑砂。孔隙体积分布和水释放曲线通过拟合货车van Schlichten函数从土芯和抓斗样品获得的解吸数据来确定。Sgi指示器对结构性壤土给出了正确的SPQ名称，但对非结构性砂、玻璃珠和建筑砂给出了错误的名称（Sgi>0.035）。这些指标表明，13种土壤管理组合中有4种具有最佳的整体SPQ，这些组合用于定义最佳的孔隙体积分布和水分释放曲线。通气性差（RFC>0.7，AC<0.14m3m−3）和结构差（PMAC<0.07，SI<7%，Sgi<0.035）的非最佳土壤相对于最佳土壤具有更大比例的小孔和过度持水，而干旱土壤（RFC<0.6，PAWC≤0.15m3m−3）的小孔比例较低，持水不足。各项指标、孔隙体积分布和释放曲线表明，添加75 t ha− 1堆肥提高了粘壤土的SPQ和玉米产量，但需要添加300 t ha− 1堆肥才能达到最佳SPQ和最大实测产量。它的结论是，Sgiindicator应明智地使用，并与其他指标的合作，用于评估SPQ;和该套件的8个指标结合使用的最佳孔隙体积分布和水释放曲线是有效的量化的物理质量刚性适度膨胀农业土壤。
The Dexter “S-value” (Sgi) is a promising new indicator of soil physical quality (SPQ), but it is not well tested against established indicators, such as relative field capacity (RFC), plant-available water capacity (PAWC), air capacity (AC), macroporosity (PMAC), bulk density (BD), organic carbon content (OC), and structural stability index (SI). Furthermore, all SPQ indicators are direct or indirect expressions of pore volume and/or pore function, but optimal pore volume-function characteristics have not been identified. The objectives of this study were to: i) compare Sgito the other seven indicators for a range of rigid to moderately expansive soils and artificial porous media; ii) use the indicators to propose an optimal pore volume distribution and soil water release curve; and iii) assess the SPQ of a compost-amended soil using indicators, pore volume distributions and water release curves. The indicators were measured in the laboratory on intact soil cores and grab samples collected from 13 soil-management combinations. Soil texture included clay loam, sandy clay loam, loam, sandy loam and sand; management included virgin soil, no-till cropping and mouldboard plough cropping. Also included were two artificial media consisting of glass beads and builders sand. Pore volume distributions and water release curves were determined by fitting the van Genuchten function to desorption data obtained from the soil cores and grab samples. The Sgiindicator gave correct SPQ designations for the structured loamy soils, but erroneous designations (Sgi>0.035) for the structureless sands, glass beads and builders sand. The indicators suggested that four of the 13 soil-management combinations had optimal overall SPQ, and these combinations were used to define an optimal pore volume distribution and water release curve. Non-optimal soils with poor aeration (RFC>0.7, AC<0.14m3m−3) and poor structure (PMAC<0.07, SI<7%, Sgi<0.035) had greater proportions of small pores and excessive water retention relative to optimal soils, while droughty soils (RFC<0.6, PAWC≤0.15m3m−3) had lower proportions of small pores and insufficient water retention. The indicators, pore volume distributions and release curves showed that adding 75t ha−1compost improved the SPQ and maize yield of a clay loam soil, but addition of 300t ha−1compost was required to achieve optimal SPQ and maximum measured yield. It was concluded that the Sgiindicator should be used judiciously and in concert with other indicators for assessing SPQ; and that the suite of eight indicators used in conjunction with an optimal pore volume distribution and water release curve are effective for quantifying the physical quality of rigid to moderately expansive agricultural soils.