Erosion effects on soil properties and soybean yield of a Miamian soil in Western Ohio in a season with below normal rainfall

Abstract

Accelerated erosion can have adverse effects on soil properties and crop yield. Therefore, an onfarm evaluation of the effects of past soil erosion on productivity was done for a Miamian soil (fine, mixed, mesic Typic Hapludalfs) in central Ohio in 1991. Three levels of soil erosion identified by a field survey and topsoil depth included slight (20–25 cm topsoil depth), moderate (15–20 cm) and severe erosion (10–15 cm). Soybean yield and soil properties under these conditions were compared with those for uneroded soil (wooded conditions with topsoil of 25–30 cm depth) and for deposition sites (30–35 cm depth). Soil properties measured included bulk density, particle density, organic carbon contents, infiltration capacity, and moisture retention at different suctions. Bulk density of 0 to 10 cm depth was significantly low in uneroded control (1.20 Mg/m 3). High bulk density of 1.45 to 1.49 Mg/m 3 was observed in moderately and severely eroded phases. The moisture retention at 0.03 MPa (0.47 V V ) was the highest in uneroded control. The highest available water capacity of the 0 to 10 cm layer (0.16 to 0.17 V V ) was observed for wooded control and slight erosion phase. Total aggregation was also the least on slightly eroded phase. Soil organic carbon content did not differ among three erosional phases with a 0 to 10 cm depth mean value of 1.03% compared with 1.83% for deposition and 2.93% for wooded soils. Similar trends were observed for the 10 to 20 cm depth. Concentrations of exchangeable K, Ca, and Mg and total CEC increased with increasing degree of erosion for both depths. There were no differences in CEC of the 0 to 10 cm depth for severely eroded and wooded soils. The rainfall received during 1991 was below normal. There were no differences in soybean yield among slight, moderate and severely eroded phases. Because of severe crusting and drought stress, crop stand was poor on slightly eroded plateau soils. Adverse soil physical conditions, low soil organic carbon content, severe crusting, and drought were likely responsible factors for low yields on slightly eroded plateau soils. Soybean grain yield was 1.5 Mg/ha for slight erosion, 1.4 Mg/ha for moderate erosion, 1.6 Mg/ha for severe erosion, and 3.1 Mg/ha for deposition soil. There were no differences in grain yield or biomass production among slight, moderate or severe eroded phases. The highest yields of soybean obtained on deposition sites were attributed to the favorable soil moisture regime during this unusually dry growing season of 1991 in central Ohio.