Emergence irregularity is often observed on coarse-textured soil (sandy soil: sandy loam, fine to very fine sandy loam). There are spots in the field that retains more moisture ; some well-compacted to achieve better contact with seed for germination. In drier areas of the field, germination can be delayed.
Dry spring aggravates germination irregularity. Producers run their center-pivot sprinklers in spring for the first time during the cropping season to achieve better germination and, attain plant growth uniformity.
The above photo shows a portion of the field with spring wheat seeds emerged.
The above photo shows a portion of the field (just few feet next to the first photo above) with no emergence. In this field there are canola residues from previous year. Traditionally, we think residues in the field will help keep moisture and reduce evapotranspiration – loss of water from surface soil. It is important to note that there are multitudes of advantages returning residues to the ground. On a fortuitous dry spring/year, however, residue may dry up the surface even more. Dry residue on a dry spring (on a coarse-textured soil) may have reduced seed to soil contact and thus, exacerbates germination irregularities. See photo below with spring wheat seeds unable to germinate.
On a dry spring (like this year), dryland production system or irrigated fields on a coarse soil where irrigation system is not yet in-place ready to use, can only hope for rain. This reminded me of a special prayer intention at times… ‘pray for rain’.
JT
Crop Physiol. Communiqué 