Main content area

Carbon Dioxide Partial Pressure in Lysimeter Soils

Robbins, Charles W.
Agronomy journal 1986 v.78 no.1 pp. 151-158
field crops, soil air, carbon dioxide, soil pH, saline soils, irrigated soils
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 CO data. 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 (), alfalfa (L.), Sordan [Sordan is a trade name for a sorghum (), sudangrass (hybrid], Sordan + leaching, cotton (L.), and tall wheatgrass (). The cropped lysimeters were irrigated at 1.25 times the consumptive use since the previous irrigation (0.20 leaching fraction). Soil P values were decreased by the gypsum treatment and increased by all other treatments as compared to check. Cotton and barley had the lowest P values for the cropped treatments and Sordan had the highest (frequently above 16 kPa). The P levels were affected by applied organic matter source, crop, plant growth rate, irrigation water application and leaching.