Effects of gravel and sand mulches on dew deposition in the semiarid region of China

Information regarding dew deposition on the stone-covered surface is scarce. The effects of gravel and sand mulches on dew condensation were studied during the late summer and fall of 1999 in the semiarid loess region of China. The results indicated that there were significant difference in daily dew amount between gravel mulch, sand mulch and dry loess soil (control). The average dew amount for gravel mulch was 0.071 mm d⁻¹ with extreme 0.022 and 0.20 mm d⁻¹. The average values for sand mulch and dry loess soil was 0.12 and 0.15 mm d⁻¹, respectively. The minimum dew amount was 0.048 mm d⁻¹ for sand mulch and 0.071 mm d⁻¹ for dry loess soil, and the maximum dew amount was approximate 0.25 mm d⁻¹ for both treatments. The results suggest that surface stone mulch can reduce dew deposition as compared to sand and dry loess soil.