Effect of soil macroporosity and aggregate size on seed-soil contact

Brown, A. D.; Dexter, A. R.; Chamen, W. C. T.; Spoor, G.

doi:10.1016/s0167-1987(96)01030-6

Cited by 36 publications

(24 citation statements)

References 13 publications

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“…Tillage is a rapid way of manipulating soil conditions to generate a seedbed. It has been shown that for good seed-soil contact the seed and soil aggregates should be approximately equal in size (Brown et al, 1996). If this were the case for sugarcane the seedbed would consist of relatively large aggregates, since the buds on sugarcane range in size from 5 to 15 mm diameter.…”

Section: Introductionmentioning

confidence: 99%

Traffic control and tillage strategies for harvesting and planting of sugarcane (Saccharum officinarum) in Australia

Braunack¹,

McGarry²

2006

Soil and Tillage Research

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Section: Introductionmentioning

confidence: 99%

Traffic control and tillage strategies for harvesting and planting of sugarcane (Saccharum officinarum) in Australia

Braunack¹,

McGarry²

2006

Soil and Tillage Research

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“…During planting, one part of the seeding unit (the opening disc) digs a furrow for the seed and simultaneously exposes buried weed seeds, while the other part (the press wheel) compacts the soil all within a space of tens of centimeters. The disturbance, caused either by the turnover of the soil or compaction, or both, stimulates the weeds to emerge because of the short exposure of seeds to light and changes in the ratios of soil gases and in water content [14,15,[39][40][41]. Compaction can also limit the available oxygen in soil, and competition from crop plants in the crop rows can reduce the density of weeds [42,43].…”

Section: Aggregation Analysismentioning

confidence: 99%

“…Soil compaction affects seeds' dormancy and germination in several ways [12][13][14]. Compaction can encourage seeds to germinate by modifying moisture conditions in the soil [39]. The greater the contact between soil aggregates and seed, the more readily water can move towards seeds [46].…”

Section: Aggregation Analysismentioning

confidence: 99%

Spatial Analysis of Digital Imagery of Weeds in a Maize Crop

Martín

Milne

Webster

et al. 2018

IJGI

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Abstract:Modern photographic imaging of agricultural crops can pin-point individual weeds, the patterns of which can be analyzed statistically to reveal how they are affected by variation in soil, by competition from other species and by agricultural operations. This contrasts with previous research on the patchiness of weeds that has generally used grid sampling and ignored processes operating at a fine scale. Nevertheless, an understanding of the interaction of biology, environment and management at all scales will be required to underpin robust precise control of weeds. We studied the spatial distributions of six common weed species in a maize field in central Spain. We obtained digital imagery of a rectangular plot 41.0 m by 10.5 m (= 430.5 m 2 ) and from it recorded the exact coordinates of every seedling: more than 82,000 individuals in all. We analyzed the resulting body of data using three techniques: an aggregation analysis of the punctual distributions, a geostatistical analysis of quadrat counts and wavelet analysis of quadrat counts. We found that all species were aggregated with average distances across patches ranging from 3 cm-18 cm. Species with small seeds tended to occur in larger patches than those with large seeds. Several species had aggregation patterns that repeated periodically at right angles to the direction of the crop rows. Wheel tracks favored some species (e.g., thornapple), whereas other species (e.g., johnsongrass) were denser elsewhere. Interactions between species at finer scales (<1 m) were negligible, although a negative correlation between thornapple and cocklebur was evident. We infer that the spatial distributions of weeds at the fine scales are products both of their biology and local environment caused by cultivation, with interactions between species playing a minor role. Spatial analysis of such high-resolution imagery can reveal patterns that are not immediately evident from sampling at coarser scales and aid our understanding of how and why weeds aggregate in patches.

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“…Aggregate size distribution of plowed layer is an important factor for rapid and uniform seed emergence. A better seed-soil contact can be obtained if seeds and soil aggregates are of similar size (Brown et al, 1996). Various reports indicated that the finer the aggregate size of the plowed layer the better the emergence (Brown et al, 1996;Dürr and Aubertot, 2000;Guérif et al, 2001;Håkansson et al, 2002).…”

Section: Introductionmentioning

confidence: 99%