|Lal, R. - OHIO STATE UNIVERSITY|
Submitted to: International Drainage Symposium
Publication Type: Proceedings
Publication Acceptance Date: March 8, 1998
Publication Date: N/A
Technical Abstract: Effects of four drain backfill treatments on grain yield, biomass production, drain outflow and soil chemical properties were studied for 5 consecutive years from 1984 through 1989 for a fine-textured soil with impaired permeability in northwestern Ohio. Four drainage treatments were: (1) tile drain (control), (2) mole drains installed above and at right angle to the existing tile drain, (3) gravel backfill over the tile drains and (4) mole drainage plus gravel backfill over the existing tile drain. Two cropping system treatments were: (a) corn-soybean rotation, and (b) alfalfa-red clover hay. Drainage treatments had no effect on mean soybean grain yield or crop stand which were on the average 2.92 Mg/ha and 343,000/ha, respectively. Alfalfa stand was, however, highest for the mole drain plus gravel backfill treatment (71.3 plants/m2) and poorest for the tile only treatment 45.9 plants/m2). There was a large variation in red clover stand with no trends with regards to the drainage treatment. Corn grain yield was significantly affected by the drainage treatment, with the lowest yield of 8.8 Mg/ha for the molechannel and the highest of 9.4 Mg/ha for the gravel backfill. Soil samples from 0 to 50 cm depth were obtained in 1987, 8 years atfer installing the treatments to evaluate treatment- induced changes in soil properties. For 0-10 cm depth, drainage treatments had a significant effect on K and CEC. Cropping systems had significant effect on soil pH and Ca. The lowest pH and Ca and Mg were observed for alfalfa. Overall, cropping systems affected soil chemical properties more than the drainage management systems.