Tillage Effects on Corn Soil-plant-water Continuum in Alfisols of Southern Ohio

Tillage alters soil physical properties and impacts soil water regime, crop’s relative water content (RWC), and root distribution. Thus, a field study was conducted to characterize and correlate root distribution and assess RWC of corn (Zea mays L.) with soil physical properties under two tillage systems i.e. no-till (NT), and conventional tillage (CT). The RWC, determined four times during a course of the day at two growth stages (V8, i.e. 60 days after planting; and R2, i.e. 90 days after planting), was significantly different (P < 0.05) among two tillage treatments. Corn grown under NT had significantly higher RWC than that under CT during both growth stages. At the V8 growth stage, the RWC ranged from 73.2 to 95.4 % under NT compared with 60.9 to 89.6 % under CT. Further, during the afternoon measurements, RWC was 15 % higher under NT than CT. A similar trend was observed during the R2 growth stage but with lesser RWC values probably due to the lower soil water content at that time. Higher root mass density (RMD) i.e. 0.50 Mg m-3 was measured in 0-10 cm depth under NT than under CT (0.34 Mg m-3), and the opposite was true for 10-20 cm depth. Due to the presence of a compacted layer (plow pan) in CT, roots were concentrated mostly in 10-20 cm depth. Further, higher RMD was measured along the row than within row.