Effect of bamboo-charcoal soil amendment on soil infiltration and water salt distribution

It is an important measure to apply chemical modifiers to improve saline soil. Bamboo-charcoal Soil Amendment (BC), as a kind of soil conditioners, have important effect on improving soil physical structure, but its dosage is crucial problem. In this experiment, the application amount of BC was set as 0‰, 4‰, 8‰, 12‰, 16‰, and 20‰ according to the percentage of dry soil mass basis, and then one-dimensional vertical infiltration experiment was carried out to explore the suitable dosage of BC in improving the salinized Chao soil. The results showed that: 1) Application of BC could increase soil wetting front depth and the cumulative infiltration. Under the same duration (240 min), compared with CK treatment, the wet front depth with BC applications of 4‰, 8‰, 12‰, 16‰, and 20‰ was increased by 4.5%, 11.9%, 10.2%, 15.3% and 17.6%, respectively, and the cumulative infiltration was increased by 5.1%, 18.4%, 11.2%, 23.5% and 23.6% separately 2) The application of BC changed the water distribution characteristics in soil profile. The water content of 0~10 cm soil layer decreased with the increasing amount of BC application, but which that of 10~30 cm soil layer increased. 3) The average value of conductivity of soil extracts increased with the increase of soil depth, and the soil salinity showed the characteristics of bottom aggregation; Cl- and Na in soil wet zone both showed “L” shaped distribution features on the soil profile. 4) In terms of comprehensive soil water and salt condition, 8‰ of BC application amount showed the best effect on soil quality improvement. However, the actual effect of this amount of BC application in field needs to be further verified.