Effect of Winter Wheat (Triticum aestivum) Straw Mulch Level on Weed Control

Abstract

Research was conducted to determine the effect of winter wheat (Triticum aestivumL.) straw mulch level on weed control in a winter wheat-ecofallow corn (Zea maysL.)-fallow rotation at North Platte and Sidney, NE, in 1981 and 1982. Wheat straw mulch was established at 0, 1.7, 3.4, 5.1, and 6.8 Mg/ha in stubble fields. After application of 1.5 times the recommended rate at corn planting, metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] concentration remained higher in unmulched soil than in mulched soil for more than 4 months, due to interception of metolachlor by the mulch. Even though the amount of metolachlor in the soil was reduced by mulch, weed control was not reduced and increased with increasing mulch level. Thus, increasing metolachlor rate was not necessary to maintain adequate weed control in no-till winter wheat stubble since mulch itself provided some measure of weed control.

Summer cover crops for weed management and yield improvement in organic lettuce (Lactuca sativa) production

“…It is generally agreed that increasing the quantity of cover crop residue will decrease the appearance of annual and broadleaved weeds (Buhler et al 1996;Crutchfield et al 1986). This was confirmed in our Table 1 for a description of Bayer codes for weed species study.…”

Weed dynamics and conservation agriculture principles: A review

“…The reduction in available light under surface residue has significant effects on seedling growth; as germinated seeds search for light they exhaust energy reserves and become etiolated, weak, and more susceptible to certain types of herbicide damage (Crutchfield et al, 1986). Light filtered through dead biomass does not change in quality, only intensity (Teasdale and Mohler, 1993).…”

“…The amount varies by crop, with small grain crops requiring less (2-8 Mg ha −1 ) and large grains more (6-17 Mg ha −1 ; Greb, 1967;Teasdale et al, 1991;Wicks et al, 1994). For example, in a wheat-maize rotation study Crutchfield et al (1986) found that at least 3.4 Mg wheat straw ha −1 was needed in order to significantly reduce weed biomass, while in a monoculture maize system in Zimbabwe Ngwira et al (2014) found 6 Mg of maize stover ha −1 was needed. In general, a linear increase in biomass results in an exponential decay in the percentage of germinated seeds that successfully emerge, although the exact relationship depends heavily on residue characteristics (Teasdale and Mohler, 2009;Ngwira et al, 2014).…”

“…Often CA systems strive to leave at least 30% of the ground covered; while this amount of residue may provide soil quality benefits it may not significantly reduce weed germination and emergence (Teasdale et al, 1991;Vidal and Bauman, 1996;Liebman and Mohler, 2001). A low light environment will have a more profound effect on small-seeded annual weeds and crops, as they are initially more dependent on light compared to perennials and large-seeded species (Crutchfield et al, 1986;Mohler, 1996).…”

“…Studies have shown that the weed suppression provided by surface residue more than compensates for reduced herbicide contact with weeds (Crutchfield et al, 1986;Derksen et al, 1995;Teasdale et al, 2003).…”