1996 Volume 73 Pages 19-24
This report describes the change of soil water properties of SHENYNAG Agricultural Universi-ty Experimental Farm for 6 months, from May to October in 1993. In order to study the properties, soil moisture suction was measured in the depth of 10 cm, 20 cm, 30 cm, 50 cm and 70 cm from ground surface at 6 : 00 PM every day. After the soil suction in the farm was measured, soil samples were obtaind in the each depth from ground surface. Soil moisture characteristic curves were determined by soil moisture external method and the soil gravity and the soil grain size distribution were measured from the samples. By scaling the data of each soil moisture characteristic curves , scaling factors were calculated. The following results were obtained : (1) The water retentivity was influenced by not only the depth but also soil properties, for examples, the grain size distribution and the dry density. (2) Rainfall during summer in 1993 was ordinary level. Rainfall of some months were very different from the normal year. Conditions in the soil water were very good for the growth of some vegetables in the field. (3) The soil layer in the depth of 20cm and 30cm was very important for the vegetables growth, while it was found that the soil water supply layer under the 30 cm was also important. (4) Soil moisture extraction pattern in the field was classified in all layer soil moisture extraction pattern.
