Soil Water Profiles, and Growth and Yield of Waxy Corn as Affected by Different Tillage in Upland Converted from Paddy Field

Abstract

In Korea, rice consumption per capita has steadily been reducing, and hence the harvested area of paddy rice decreased by 18% from 892,074 ha in 2010 to 729,814 ha in 2019 during last decade, leading to the potential to stimulate upland crop production in converted-upland from paddy field. Here, we examined how tillage practice, rotary (RT) in 12cm depth vs. rotary combined with deep tillage (RTDT) in 25cm depth, would affect vertical profiles (0 to 40 cm at 10 cm interval) of soil water and, growth and yield parameters of waxy corn (Zeay Mays L., ceratina, cv. Ilmichal) grown as sequential cropping of barely in upland field converted from paddy field. With rainfall and sprinkler irrigation, vertical profiles of soil water were varied greatly (20 cm > 40 cm > 30 cm > 10 cm) over whole season in RTDT plot, but not in RT plot. Tillage treatments did not alter plant height, SPAD value, ear setting height, ear number, ear length and ear width of waxy corn. However, the RTDT significantly increased stem diameter by 7.7% (27.1 mm vs. 29.1 mm), above-ground biomass by 28.3% (1,170 g m-2 vs. 1,501 g m-2) and ear fresh yield by 22.4% (1,278 g m-2 vs. 1,564 g m-2). The results suggest that tillage management is likely to be an option to secure upland crop production in drained-paddy which has a potential of crop loss by excessive moisture injury. However, the results that we observed were derived from the first-year upland field converted from paddy field, highlighting a necessity of further studies in second- and third-year upland field converted from paddy field to clarify the long-term effect of tillage practices on waxy corn production. Vertical profiles of soil water in upland field converted from paddy field were varied greatly in rotary combined with deep tillage plot (B), but not in rotary only plot (A).