Submitted to: Western Society of Crop Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 4, 2005
Publication Date: June 22, 2005
Citation: Grabber, J.H., Massingill, L.J. 2005. Yield and soil nitrate levels of cover crop and living-mulch systems for corn silage fertilized with manure. Western Society of Crop Science, June 19-22, 2005, Bozeman, Montana. 2005 CDROM Technical Abstract: In replicated plots in southern Wisconsin, we compared yields and soil N levels of continuous corn grown with relay-seeded Italian ryegrass, fall-seeded rye, or no cover to a 2-year rotation of corn grown with kura clover living-mulch or relay-seeded red clover followed by one year of clover production. Manure slurry was applied on a P-basis in November or April to all plots and additional fertilizer was applied to continuous corn plots at planting in early May to supply 180 kg/ha of available N. In 2003 (dry summer), corn silage yields ranged from 18.4 to 23 Mg/ha and were greatest with red clover and lowest with ryegrass. In 2004 (wet spring, cool summer), corn silage yields ranged from 16.6 to 20 Mg/ha and were greater with clovers and no cover than with rye and ryegrass. Cover crop/living mulch growth by late October was greatest with ryegrass (1 Mg/ha); spring growth by early May was similar for rye, kura and red clovers in 2003 (1 Mg/ha) and greatest for rye in 2004 (3.5 Mg/ha). June soil nitrate (0-30 cm) ranged from 21 to 43 mg/kg in 2003 and from 7 to 12 mg/kg in 2004 and was highest for corn grown with ryegrass. In both years, soil nitrate levels (0-120 cm) after corn ranged from 31 to 54 kg/ha and were greatest with clovers and lowest with ryegrass. Fall nitrate levels dropped to 10 to 37 kg/ha when a year of clover production followed corn. In the year following corn, yields of red clover were greater than kura clover in 2003 (11.4 vs. 8.6 Mg/ha); yields of both clovers were similar in 2004 (8.3 Mg/ha) even though red clover was reseeded in April due to relay seeding failure in 2003. Timing of manure application did not influence yields or soil N levels.