Wheat Response to Row Spacing in Relay Intercropping Systems

Abstract

Relay intercropping of soybean [Glycine max (L.) Merr.] or cotton [Gossypium hirsutum L.] into standing wheat [Triticum aestivum L.] allows for earlier planting of the summer crop than with sequential double‐crop systems. Relay intercropping has been evaluated using modifications of standard planting and harvesting equipment as well as specifically designed equipment. In most relay intercropping systems, wheat is drilled in the fall in a row pattern that provides traffic‐tire lanes as guides for planting the summer crop. Also, row spacing for wheat in relay intercropping is usually wider than for conventionally planted wheat. This field study, conducted during 1991‐1992 and 1992‐1993 near Blackville, SC, on a Varina loamy sand (clayey, kaolinitic, thermic Plinthic Paleudults), compared the yield and yield component response of soft red winter wheat produced with two different intercropping production schemes to the yield and yield component response of conventionally planted wheat. Yields of wheat planted in skip‐row schemes designed to allow for relay intercropping of either soybean or cotton were not significantly different from yield of conventionally planted wheat under the given experimental conditions. For conventionally planted wheat, wheel traffic on certain rows reduced yields by as much as 50% compared with nontraffic rows. In the schemes designed to allow for relay intercropping, wheat grown with wider‐spaced rows (0.31‐0.61 m) compensated with respect to yield on an area basis compared with wheat grown with conventionally spaced rows (0.15‐0.20 m).

Biochars impact on water infiltration and water quality through a compacted subsoil layer

“…However, deep tillage has a few issues such as requiring large tractors with significant horsepower to pull each shank (14-20 Kw), consumption of copious amounts of fuel (20-25 L ha À1 ; Karlen et al, 1991), and deep tillage is usually needed annually to prevent re-setting of the dense soil layer (Threadgill, 1982;Porter and Khalilian, 1995).…”

Deep tillage management for high strength southeastern USA Coastal Plain soils

“…For these soils, management involves noninversion tillage 0.3-0.4 m deep to disrupt the hard layer. Though residual effects of tillage can remain for years afterward as seen by Munkholm et al (2001) and Baumhardt and Jones (2002), tillage is still performed annually on these southeastern USA Coastal Plain soils because annual re-compaction can reduce root growth and yield even though it is not complete (Porter and Khalilian, 1995). A recent study (Frederick et al, 1998) showed that deep tillage significantly increased yield when it was performed twice a year, before double-cropped wheat and drilled soybean.…”

Tillage Management for Cotton in Southeastern Coastal Soils during Dry Years

“…Deep tillage of these coastal soils is recommended annually (Porter and Khalilian 1995;Simoes et al 2009) to reduce soil strength and promote root growth throughout the profile to encourage water and nutrient uptake. In some studies, residual effects of deep tillage were shown to be effective for years (Munkholm, Schjønning, and Rasmussen 2001;Scanlon et al 2009), especially if traffic is limited to specific midrows (Frederick et al 1998), whereas in other studies tillage effects were gone after 3 years or less (Busscher et al 1995;Shukla, Lal, and Ebinger 2003).…”