Suppression of weeds and weed seeds in the soil by stubbles and no-tillage in an arid maize-winter wheat-common vetch rotation on the Loess Plateau of China

Abstract

Reduced tillage provides ecological and economic benefits to arable land on the Loess Plateau of China, where soil erosion has long been a serious problem and soil water availability is largely restricted. However, high abundances of weeds in reduced tillage systems cause significant yield losses. In this study, we explored the effects of no-tillage and stubble retention on the number and density of weeds and weed seeds in a 12-year maize-winter wheat-common vetch rotation on the Loess Plateau. Four treatments including conventional tillage, no-tillage, conventional tillage+stubble retention and no-tillage+stubble retention were designed and applied. We found that no-tillage increased the number of weed species and weed density in most of the crops, while stubble retention decreased weed density in maize and tended to suppress weeds in both no-tillage treatments (no-tillage and no-tillage+stubble retention). No-tillage led to an increase in the number of weed species in the weed seedbank and tended to increase seed density during the spring growth of winter wheat, but it decreased seed density during post-vetch fallow. Stubble retention tended to reduce seed density during the spring growth of winter wheat and post-vetch fallow. We concluded that no-tillage can promote weeds in the experimental crop rotation, while stubble retention suppresses weeds in untilled fields. The combined effects of stubble retention and no-tillage on weed suppression varied among the three crops. Based on these results, we recommend stubble retention in untilled legume-crop rotations on the Loess Plateau to improve the control of weeds.

Impact of Tillage and Crop Residue Management on the Weed Community and Wheat Yield in a Wheat–Maize Double Cropping System

“…This study indicated that tillage was an effective measure to suppress the weed occurrence, especially in the early stages of wheat growth (Figures 1a and 2a), being consistent with previous researchers [14,47]. These findings could be primarily attributed to the disturbance of tillage burying weed seeds in the deep soil layer, decreasing the emergence of seedlings deriving from seeds [47].…”

“…Agronomic practices can affect the weed flora and species composition of the weed community and soil seed bank in arable fields [7]. Crop rotation [8,9], fertilization [10][11][12][13], tillage [14][15][16], and crop residue retention [17][18][19] are effective measures to control weeds. No-till has been widely accepted in recent decades for many environmental benefits, such as reducing run-off, improving nutrient cycling, reducing soil degradation, decreasing water and soil pollution, and enhancing the activities of soil biota [20].…”

“…No-till has been widely accepted in recent decades for many environmental benefits, such as reducing run-off, improving nutrient cycling, reducing soil degradation, decreasing water and soil pollution, and enhancing the activities of soil biota [20]. However, a high infestation of weeds has been recognized as an obstacle in the large-scale adoption of conservation tillage (no-till or reduced tillage) [14,21,22]. Weed controls differ among different tillage systems with small seed species favored by conservation tillage systems for the composition of weed community changes, thus requiring different weed control strategies [23].…”

Allelopathic Potential of Teff Varieties and Effect on Weed Growth

“…At this time, we believe there are no research reports on the allelopathic effect of teff on different weed species. Most reports have focused on the allelopathic effect of certain plant species on teff [19,20,[35][36][37][38][39][40][41][42][43]. For example, leaf extracts from different eucalyptus species and Parthenium hysterophorus had an effect on the germination and early growth of teff [19,20].…”

The regional difference in engineering-control and tillage factors of Chinese Soil Loss Equation

“…TCN is a unique farming method in the Southwest China purple soil region. It is a comprehensive farming method by gathering soil to build ridges and fertilizing in furrows (Liu et al 2013b;Liu and Huang 2013;Yang et al 2018;Niu et al 2019;Wang et al 2020a;Wang et al 2020c;Zhang et al 2020).…”