Effect of Tillage on Soybean Growth and Seed Production¹

Abstract

Soybean [Glycine max (L.) Merr.] grown without tillage often produces less grain on silty clay loam soils than soybean produced under conventional tillage. A 3‐yr (1982, 1983, and 1984) study was conducted to gain a better understanding of the factors affecting yield differences between conventional and no‐till soybean production systems on silty clay loam soils. The study was conducted near Columbia, MO, on a Mexico silt loam soil (Udollic and Mollic Ochraqualf). Conventional tillage consisted of spring moldboard plowing and secondary tillage. The no‐till treatment received a foliar application of glyphosate [N‐(phosphonomethyl) glycine] at the time of planting. Soybean grain yields were less for no‐till in 1982 (1890 kg/ha vs. 2260 kg/ha) and greater in 1983 (2310 kg/ha vs. 1510 kg/ha) and 1984 (1870 kg/ha vs. 1670 kg/ha). Seasonal rainfall was above average in 1982 and below average in 1983 and 1984. In 1983 and 1984, soybean in the no‐till plots depleted greater soil moisture at soil depths of 840 and 990 mm and had less plant water stress during podfilling, with afternoon leaf water potential measurements averaging 0.11 MPa greater in 1983 and 0.34 MPa greater in 1984, than soybean grown under conventional tillage. Conventionally tilled soybean had a greater yield potential due to greater vegetative growth, but with less than adequate rainfall the soybean in no‐till had less plant water stress, resulting in greater yields.

Effect of planting date and tillage system on soybean root growth

“…But, other research has shown that conventional tillage produced higher yields than no-tillage (Guy and Oplinger, 1989;Oplinger and Philbrook, 1992). Webber et al (1987) observed that in two out of three years no-tillage produced higher yields than conventional tillage. The difference in yield results among studies may be related to location.…”

“…Yield comparisons between conservation tillage and clean tillage systems are often affected by precipitation. Notillage soybean often yield more than soybean planted after clean tillage in dry seasons (Leuschen et al, 1991;Lai and Tanaka, 1992;Webber et al, 1987).…”

Rye cover crop management impact on soil water content, soil temperature and soybean growth

“…However, later cover.toP ffig ,gs will maximize residue dry matter production, promoting subsequent soil water conservation (Moschler et al 1967)' Field studies have shown that straw rates higher than 3 Mg ha-l signifrcantly increased soil water storage of mulched plots wf,en compared to bare soil plots (Aase and Tanaka tg8Zl. While increases in soybean yields due to soil water conservation by plant residues have been reported in some studies (Webber-et al 1987;Edwards et al 1988), other studies have encountered no yield differences (Elmore 1987;NeSmith et al 1987). Decreases in yields observed in no-till soybeans have not been associated with the lower soil temperaoies ttrat occur under no-tillage systems (Tollner et al 1984 (Weston 1990 Fehr et al (1971).…”

Crop and weed response to nutrient source, tillage and weed control method in a corn-soybean rotation

“…Soybean yields were reduced in CP treatments at the clay loam site in 1997 and at both sites in 1998, suggesting the persistence of the early season effects. Other experiments have shown that higher soil water storage and colder temperatures in minimum tillage delayed seed germination and slowed seedling growth rate in corn and reduced soybean yield (Hairston et al 1984;Webber et al 1987;Tekrony et al 1989). Corn yield was reduced with CP tillage with mechanical weed control at the clay site in 1997 and 1998.…”