The practice of sowing rapeseed on Polish farms is very flexible. Row seeders, precision seeders are used here, but broadcast sowing is also used. The row spacing is between 12 and 45 cm, and sometimes even more – up to 75 cm. Attempts are also made to sow in so-called double rows, i.e. sowing "stripes" of two rows of seeds at a narrow distance, with the individual double-row stripes being more widely spaced from each other.
Narrow Row Spacing: Advantages and Disadvantages
One of the most important advantages of narrow row spacing in rapeseed cultivation is the quick and precise closure of the inter-rows, thanks to which the plants better suppress weeds, and also limit the evaporation of water from the soil. Canadian experts in canola agrotechnology also talk about the so-called solar panel effect, i.e. the earlier the inter-rows are covered by leaves, the greater the intensity of photosynthesis and thus the productivity of the plants.
On the other hand, the disadvantage of sowing in narrow rows is considered to be poor aeration of the field, which is supposed to favor the occurrence of fungal diseases. It is worth mentioning here that in Canadian experiments with canola , a worse phytosanitary condition of plants sown in wide rows was found, which was justified by… greater air flow in the field, which facilitated the spread of fungal spores with the wind.
Farmers' observations also show that a small distance between rows encourages rape to raise its growth cone high in autumn. It is also believed that a narrow row spacing limits the development of leaf blades and the formation of lateral branches – such a canopy architecture may work well in the case of population varieties of rape, which "build" the crop primarily on the main shoot, but may limit the possibilities of modern hybrids.
Read more
How long do seed dressings protect rapeseed?
Wide row spacing: advantages and disadvantages
Sowing in wider rows gives rapeseed more living space, which the plants willingly use, developing a good leaf rosette and creating a thick, deeply reaching root. Wider inter-rows encourage the development of side shoots, which in the case of modern, high-yielding hybrid varieties are most responsible for the yield. Another advantage is better aeration of the field, and thus improved plant health, which, however, does not have to be the rule – as the above-described experiences from Canada have shown. A larger distance between rows allows for mechanical control of weeds on the plantation.
At the same time, it is noted that wide-row sowing reduces the competitiveness of plants in the field in relation to weeds. In practice, wider inter-rows are most often combined with point sowing and strip-till cultivation, which, like other no-till technologies, is more demanding in terms of herbicide protection – especially when rape appears after cereals in the crop rotation.
Read more
Strip-till: the ideal crop for rapeseed?
Practice is changing
Most agronomy textbooks recommend that winter rapeseed be sown with a row spacing of 15-20 cm. However, practice takes its toll and each grower finds his or her own ideal solution. In recent years, we have seen the spread of hybrid varieties with high yield potential in rapeseed cultivation. Increasingly, farmers are deciding on no-till and strip cultivation of rapeseed and precision sowing of seeds with a wide row spacing. The direction is the greatest possible precision.
– All new hybrid varieties work very well in strip cultivation and point sowing. Sowing in wide rows means that hybrid varieties develop side shoots very well, which is important for the yield. In our experience over the last three years, regardless of weather conditions, a spacing of 45 cm and sowing of 35 seeds/m2 worked best. However, with a wide spacing, you need to watch out for herbicide treatments, it is worth using them sequentially – said Dr. Szymon Hoppe, Market Development Advisor at Bayer, in an interview with farmer.pl.
The expert adds that regardless of the adopted sowing density and method, it is necessary to ensure that the seeds are evenly distributed over a unit of surface area, which will provide each plant with adequate access to water and nutrients.
Read more
Which variety of winter rapeseed to choose? LOZ recommendation for Integrated Production
