An investigation of weed seed banks reveals similar potential weed community diversity among three different farmland types in Anhui Province, China

Abstract

Crop type is one of main factors influencing weed community structure. However, the identity of weed communities associated with the cultivation of different crops in farmlands remains largely unclear. A field survey of weed seed banks was conducted in 2 280 fields at 228 sites of 62 locations representing three different types of farmland (95 paddy, 73 summer-ripe, and 60 autumn-ripe farmlands) along the bank of the Yangtze River in Anhui Province, China. A total of 43 families and 174 species of weeds were found in these weed seed banks. A comparison of the composition of weed groups in the seed banks showed that the species number and density percentage of grass, sedge and broadleaf weed groups were similar among the different types of farmland. The seed banks of all three farmland types shared 71 common weed species, accounting for 40.80% of the total number of species. These common weeds, which were both associated and not associated with crops, accounted for 91.71% of the total dominance degree among all farmland types. The crop-associated weed species were distributed in all soil layers of each farmland type. The Shannon-Wiener index H´ (description of species diversity which is more sensitive to dense species) and Pielou's evenness index J (description of species evenness) in summer-ripe farmland were similar to those in autumn-ripe farmland but differed from those in paddy farmland. However, the Simpson's index D (description of species diversity which is more sensitive to sparse species) was similar among all three farmland types. The results of similarity comparison indicated that although the aboveground weed community differed among the different cropping patterns, the weed species composition in the soil seed bank was still similar. Consequently, our results demonstrate that after the implementation of long-term monoculture patterns, weed species compositions in the soil seed bank in different farmlands become homogenized regardless of the crop type.

The Influence of Long-Term Different Crop Rotations and Monoculture on Weed Prevalence and Weed Seed Content in the Soil

“…When winter rye was grown in crop rotations, monocotyledonous weeds were similarly widespread and did not differ significantly from monoculture, except for three-course crop rotation, where they were the least numerous. The results of other researchers [37] also show that long-term monocultures do not reduce the species composition of weeds. In the monoculture of our experiment, the abundance of monocotyledonous weeds was on average as much as eight times lower compared to the cultivated rye crops after different pre-sowing in different crop rotations.…”

“…The results show that the number of weed seeds in crops under conventional arable tillage system can vary both in different crops and in different crop rotations. The results of research conducted by He et al [37] show that when assessing the weediness of long-term monocultures, the species composition of weeds in the soil bank in different crop fields becomes homogenized, regardless of the type of crop. This study showed that winter rye was dominated by the same annual weeds seeds all the years of the study-namely, Chenopodium album and E. crus-galli, but other types of weeds were also found: Stellaria media, Fallopia convolvulus, J. bufonius, Sinapis arvensis, Lamium purpureum, Persicaria lapathifolia.…”

Utilization of Forage Crops as an Effective and Eco-friendly Method for Weed Growth Control and Distribution in an Immature Rubber Plantation

“…In the rainy seasons (S1) and ( S2), the study found that the whip grass and ruzi grass tended to control mainly the weeds from the Poaceae and Asteraceae families with the maximum ratios. As the forage crops impacted the weed species and suppressed the weed growths, the study suggested that it could be effectively applied in field crop production as integrated weed management (Meiss et al, 2010) although the diversity of weed communities differed among the various cropping patterns and seasons (He et al, 2019).…”

Soil seed bank richness, abundance and density across spatial scales and global biomes

“…Indeed, there was a large variation in sampling effort across records. The minimum total number of samples was one sample, used in 19 studies, with the maximum being 114 000 samples taken in arable systems representing 224 m 2 of soil sampled across 228 sites in China (He et al 2019). The minimum total sampled area was 0.0015 m 2 (5 sites, 15 total samples) in temperate broadleaf and mixed forests from the United States (Hausman et al 2007), with the maximum being 816 m 2 (20 sites, 20 400 samples) in another large arable study in the UK (Holland et al 2008).…”