Influence of Tillage Depths and P‐Fertilizer Application Rates on the Yields of Annual Cropped Winter‐Grown Wheat¹

Abstract

Because of different climatical conditions during the growing season from those of reported experiments in literature and the relatively few data about annual cropped winter‐grown wheat (Triticum aestivum L.) yield response to depth of tillage and to incorporation of previously broadcasted P‐fertilizer, a 2‐year field trial was conducted to evaluate the effects of three tillage depths, 10, 20, and 40 cm; and three P‐fertilizer rates on grain yields and dry matter production. The three P‐fertilizer rates were: no P‐fertilizer, 12 kg P/ha per 10 cm depth of tilled soil, and a flat 60 kg P/ha rate. The field trial had a randomized split plot design with four replications and was simultaneously conducted on two soils of different texture. Grain yields, dry matter production, and P‐uptake over 2 years were not influenced by depths of tillage. Initial development of wheat plants was better on shallow tilled soil. Added P‐fertilizer markedly increased grain yields, dry matter production, and P‐uptake. P‐fertilizer rates based on volume of tilled soil were as effective as the flat P‐fertilizer rate. Dry matter production response to P‐fertilizer was influenced by soil texture, indicating limiting P‐availability with decreasing clay content of soil. From the data obtained it can be concluded that increasing depth of tillage has no significant effect on annual cropped winter‐grown wheat yields and secondly that there is no need to incorporate P‐fertilizer deeper than the top soil layer of 10 cm. Therefore, if plowing a wheat stubble becomes necessary, P‐fertilizer rate can be based on the P‐availability of the sampled top soil layer after plowing and adjusted to the depth of the planned seedbed preparation to keep P‐availability at the recommended level for wheat growing.

The effect of deep-tillage depths on crop yield: A global meta-analysis

“…Conversely, soil management, for instance, adding nitrogen fertiliser, irrigation practices, and changing cropping systems or crop species mostly increase crop yield under deep tillage (Figures 4D, E, G, H). The associated mechanisms have been explained by many researchers (Stibbe and Kafkafi 1973, Barber and Díaz 1992. Interestingly, we found that topsoil (< 37 cm) straw incorporation buffered the positive effect of deep tillage on crop yield (Figure 4F), which highlights that straw returning needs a deeper depth to complete decomposition and to avoid affecting seed emergence (Li et al 2022).…”

“…In Europe, a shallow working depth (5-10 cm) was recommended for wheat and barley by Arvidsson et al (2013), but 20-25 cm was also suggested for wheat and barley by Arvidsson (1998). Similar inconsistent situations were observed in Asia, Africa, South America, and Australia (Stibbe and Kafkafi 1973, Adeoye 1982, Barbosa et al 1989, Barber and Díaz 1992, Hammad and Dawelbeit 2001, Kothari et al 2003, Hemmat 2009, Berhe et al 2012, Salem et al 2015, Zeyada et al 2017, Sun et al 2019, Shen et al 2021, Gu et al 2022, the optimum tillage depth ranges from 10 cm to 50 cm for soybean, wheat, and maize under differential countries. Obviously, the optimum tillage depth was highly scattered in differential research, this is presumably largely due to the strongly site-specific effects of tillage depth on crop yields.…”

Is Deep Zone Tillage Agronomically Viable in Minnesota?

“…Research has been conducted for decades on the efficacy of deep plowing and other forms of subsoil tillage to ameliorate subsoil compaction (3,5,8,9,11,15). The results are mixed, even in areas with defined plow pans such as in the southeastern United States (12).…”