Carbon Dioxide Partial Pressure in Lysimeter Soils1

Publisher Website
Google Scholar
Abstract
The carbonate chemistry portion of mechanistic salinity models is generally the weak link in describing salt reactions in soils. This is primarily due to a lack of available soil atmosphere CO2data. Carbon dioxide concentrations were measured at 0.25, 0.50, and 0.75 m depths in 0.30 m diam lysimeters containing 1.0 m of sodic soil. Four non‐cropped treatments included a check, gypsum, fresh manure, and chopped alfalfa irrigated weekly with 70 mm (5.0 1) of tap water (EC=0.7 and SAR=1.7). Six cropped treatments included barley (Hordeum vulgare), alfalfa (Medicago sativaL.), Sordan [Sordan is a trade name for a sorghum (Sorghum bicolor), sudangrass (Sorghum sudanesehybrid], Sordan + leaching, cotton (Gossypium hirsutumL.), and tall wheatgrass (Agropyron elongatum). The cropped lysimeters were irrigated at 1.25 times the consumptive use since the previous irrigation (0.20 leaching fraction). Soil PCO2values were decreased by the gypsum treatment and increased by all other treatments as compared to check. Cotton and barley had the lowest PCO2values for the cropped treatments and Sordan had the highest (frequently above 16 kPa). The PCO2levels were affected by applied organic matter source, crop, plant growth rate, irrigation water application and leaching.

This publication has 4 references indexed in Scilit: