Seed row placement relative to the previous crop stubble row can harness systems benefits on water repellent sands

Abstract

Context Innovations to improve crop establishment are critical to unlocking the full potential of early sown winter cereal cropping systems. Aims The aim of this set of experiments was to evaluate the systems benefits of near-row sowing treatments for surface soil water, crop establishment, crop competition with weeds, root disease infection and cereal crop yield on sandy soils in low-rainfall environments. Methods Six of the 10 site–years evaluated were on water repellent sands with the remainder on sand and loam. A second set of experiments on a water repellent sand evaluated if furrow applied amendments to increase soil fertility in the crop row might generate additional benefits to the near-row sowing effect. Key results Significant grain yield benefits from near-row placement (up to 30%) were measured in 2 site years and these were associated with crop establishment gains, improved access to furrow soil water storage and weed seed reductions, which occurred in 3 site years. In a water repellent sand, near-row placement combined with extra nutrition input generated an additional grain yield benefit (+0.4 t/ha), as did a one-off 22 cm deep furrow tilling treatment designed to bring deeper soil moisture into the seed zone (+0.4 t/ha). Conclusions Near-row placement of crop seeds can provide systems benefits in water repellent sands. The conversion of these benefits to yield benefits occurred in 30% of site-years tested on repellent sand. Implications Further innovation is required to ensure that these seeder-based innovations generate predictable responses and scaled up evaluation is necessary to fully understand the systems and landscape level benefits of improved crop establishment in soils that often suffer low and uneven crop establishment numbers.