Soil texture analyses using a hydrometer: modification of the Bouyoucos method

Abstract

Bouyoucos (1936) proposed a more rapid and simpler procedure called the hydrometer method. Both analytical techniques are sedimentation procedures accepted as standard techniques for particle-size analysis. The sand, silt, and clay contents of several soil samples were determined using the Pipette method as a control and compared with the Bouyoucus, the Bouyoucos Modified (Bouyoucos_M) and the Bouyoucos Modified with gravimetric determination of the sand content (Bouyoucos_M-T) methods. Data obtained from these procedures was used to assess soil textural class, the soil erodibility coefficient (K), the water retained at field capacity (FC) and the permanent wilting point (PWP). In the Bouyoucos_M method, the soil organic matter (SOM) was destroyed and the dispersingagent concentration was increased. In the Bouyoucos_M-T method, the sand was quantified gravimetrically by sieving samples through a 53 µm mesh. The hydrometer and Pipette methods measurements correlated well. The Bouyoucos and the Bouyoucus-M methods overestimated the sand content. The performance of the Bouyoucos_M-T method did not differ from that of the Pipette method. Compared with the Pipette method, the Bouyoucus method underestimated the clay content, and the Bouyoucos_M method did not differ from the Pipette method. The values obtained with the Bouyoucos_M and the Bouyoucos methods underestimated the FC and the PWP, and Bouyoucos_M-T method did not differ from estimations based on the Pipette method data. The assessed K value was underestimated with the Bouyoucos_M method. The Bouyoucos and the Bouyoucos_M-T methods estimated the K values similar to the Pipette method. The Bouyucus_M-T method is suitable for determining the soil texture and inferring soil properties but is unacceptable for assessing the class texture for soil taxonomic classification.

Application and recalibration of soil water retention pedotransfer functions in a tropical upstream catchment: case study in Bengawan Solo, Indonesia

“…the pipette method (Gee and Bauder, 1986). Nevertheless, soil particle distribution information obtained from both methods was not found to result insignificantly different predictions of the SWR capacity (Beretta et al, 2014).…”

Estimation of Soil Loss Tolerance in Olive Groves as an Indicator of Sustainability: The Case of the Estepa Region (Andalusia, Spain)

“…where DBD is dry bulk density (g cm −3 ); DSM is dry soil mass (g); V i is initial sample volume (cm 3 ). In addition, the percentage of gravel (soil particles between 2 mm to 6 cm) in each treatment was estimated, and a textural soil profile was made using the Bouyoucos method [41,42] and following the USDA criterion (sands: 2 mm-50 µm; silts: 50-2 µm; clays: <2 µm). Chemically, edaphic pH was evaluated by direct estimation (i.e., pH-meter) in water solution.…”

Comparison of the Mangrove Soil With Different Levels of Disturbance in Tropical Agua Brava Lagoon, Mexican Pacific

“…The sand, silt and clay content of the samples were determined by modification of the Bouyoucos method (Beretta et al, 2014). The field moisture content was obtained by subtracting oven-dry weight from wet weight of the field samples.…”