Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
Volume 9
Issue 4
Walczyk J. , Tylek P. 2006. SINGLE-SEED SOWING IN TROUGHS, EJPAU 9(4), #49.
Available Online: http://www.ejpau.media.pl/volume9/issue4/art-49.html


Józef Walczyk1, Paweł Tylek2
1 Department of Forest Works Mechanization, Agricultural University of Cracow, Poland
2 Department of Forest Work Mechanisation, University of Agriculture in Krakow, Poland



The modification of a garden single-seed drill for sowing in troughs is presented in this paper. Necessary construction changes made to adapt the driving of the tractor with the drill alongside the troughs with sowing sections working in the troughs are described. Switching of the modified drill from work in troughs to sowing under field conditions requires a short period of time. Single-seed sowing of Scots pine was carried out, and it was compared with hand sowing. Also the evaluation of sowing and morphological characteristics of seedlings was made.

Key words: single-seed sowing, production of seedlings in troughs, single-seed drill.


Polish forestry accepted the challenge to not only maintain a sustained forest development but also to afforest about 1.7 million hectares of former farmland with soils of worse classes. It is planned to increase the forest cover in Poland from the present 28.8% of the total area of the country to 32% in 2020. This would require production of a great amount of planting stock of high vitality with symbiotic fungi in the root system of plants [1]. Only such plants should be used in afforestation of degraded lands and former farmland [2, 3, 5, 7]. This kind of planting stock is produced in container nurseries, but also in troughs. The peat substrate used in greenhouses and troughs requires the application of about 8 liters of fungal inoculum per 1 m2 of the substrate [4, 7].

The technology of sowing in troughs used in forest nurseries till now did not meet the modern standards. For this reason the Department of Forest Works Mechanization, Agricultural University of Cracow, attempted to modify a garden drill to adapt single-seed sowing of seeds of forest trees in troughs.

The single-seed sowing, using pneumatic drills which are fit to sow seeds of forest trees because they are not sensitive to seed shape, requires seeds of high germination capacity [6].


The aims of this research were:

  1. to elaborate and carry out changes in construction of a standard drill used in vegetable gardening and farming;

  2. to test the modified single-seed drill and sow Scots pine in troughs;

  3. to compare the quality of single-seed sowing with hand sowing traditionally used in production of planting stock in troughs.


The production of planting stock in troughs is widely used but there is a complete lack of machines for preparation of substrate and sowing [8]. Troughs are built in pairs, side by side, and there is a driving road between the pairs (Fig. 1).

Fig. 1. View of experimental troughs

The troughs are 1200 mm wide (internal dimension) and 400 mm high. The cross-section of a trough is shown in Fig. 2.

Fig. 2. Cross-section of a trough

A field single-seed drill of Agricola Italiana firm was used for sowing in troughs. It is a drill suspended on a three-point linkage system of a tractor. To adapt the drill to sowing in troughs it was necessary to modify it. The modification consisted of extension of the right side of the drill frame by a meter. For this purpose the original steel profile of the drill was used (Fig. 3).

Fig. 3. The frame profile for a side extension

The profile was connected with the main frame using a specially made mandrel fitted to the opening of the frame profile and its extension, and a clamping ring which did not allow the extension to revolve in respect of the main frame, and to move out (Fig. 4).

Fig. 4. Elements of fastening of the frame extension: a – mandrel, b – clamp
a b

The sowing sections were fastened on the frame extension. Since the substrate surface was about 30 cm above the road surface on which the tractor and supporting wheels of the drill move it was necessary to extend the brackets fastening the drill wheels. For this purpose insertions of sheet iron, 8 mm thick, were made (Fig. 5).

Fig. 5. Insertions serving the extension of drill wheel brackets

The insertions were fastened in the place of openings fastening the wheels to original bracket arms (Fig. 6).

Fig. 6. The method of fastening insertions to original arms of drill wheels

The subsequent modification consisted of the change of place of the drill gearbox. In the original version the gearbox together with the drive wheel was placed on the left side of the drill. The frame extension was made on the right side of the drill, and in order to use the original driving shaft the gearbox was also fastened on the right side where it can work at the side or central fastening of the drill sowing sections. Changing of the gearbox place did not require any changes in drill construction. The final modification consisted of replacing the original conduits of negative and positive pressures with longer conduits permitting to connect the fan and compressor (their positions were not changed) with the sowing sections fastened on the side. The view of the drill after modification is presented in Fig. 7.

Fig. 7. View of the drill after modification with sowing sections mounted on its side for sowing in troughs
a    b   


The experimental sowing in troughs was carried out using the modified drill. Using five side sowing sections 10 rows were seeded in a single passage. The distance between sections was 20 cm. The following three versions of the experiment were carried out: 1) 20 rows were seeded in two passages with seed spacing in a row of 39 mm; 2) 10 rows were seeded in one passage with seed spacing in a row of 19 mm; and 3) 20 rows were seeded in two passages with seed spacing in a row of 31 mm (Fig. 8).

Fig. 8. View of a sown seedbed: a – in one drill passage, b – in two drill passages
a    b   


The results of the study on sowing in troughs using a single-seed drill are presented in Table 1. For comparison the row hand sowing of Scots pine was carried out using 0.8 kg of seed per are. Sowing was carried out on May 4, 2006, and seedlings were counted on Sept. 28, 2006.

Table 1. Results of sowing of Scots pine seeds in troughs


Single-seed sowing,
number of rows in a trough

Hand sowing




Crosswise rows

Spacing in a row (mm)





Theoretical number of seeds per are





Number of seedlings per are





Sowing success (%)





Five months after sowing date 67.52% of seeds germinated on the average in single-seed sowing, and only 45.96% in hand sowing. This means that by single-seed sowing over 20% of seeds may be saved because of better germination and growing conditions only. Also in the case of single-seed sowing there are better conditions for development of seedlings, and considerably less sidling losses as well as less bad quality seedlings (Table 2), which is a further saving.

Table 2. Morphological characteristics of seedlings sown in roughs after first vegetation season


Length of the above-ground part

Length of the roots

Diameter of the root-neck

Mass of the above-ground part

Mass of the roots

Single-seed sowing
20 rows







Coefficient of variation (%)






Percentage of the 1st class quality standard






Single-seed sowing
10 rows







Coefficient of variation (%)






Percentage of the 1st class quality standard






Hand sowing in rows







Coefficient of variation (%)






Percentage of the 1st class quality standard






Roots of plants produced by single-seed sowing are less tangled because of a greater spacing, and therefore less damage is done during lifting. It was also observed that tending treatments are easier after single-seed sowing. View of the seeded troughs is presented on Figures 9 and 10. The time required for hand sowing of one trough in rows amounted to 64 working hours, while seeding by the single-seed drill only 30 minutes.

Fig. 9. View of seedlings in a trough 60 days after sowing: a – sowing in two passages – 20 rows, b – sowing in one passage – 10 rows
a    b   

Fig. 10. View of seedlings in a trough 210 days after sowing: a – sowing in two passages – 20 rows, b – sowing in one passage – 10 rows
a    b   


  1. The modification of the Agricola Italiana single-seed drill permitted to use it for sowing in troughs, and it did not limit its usage in open field forest nurseries.

  2. The single-seed sowing in troughs permitted to mechanize the sowing process resulting in a better spatial distribution of seeds. It also gave almost 130-fold increase of work efficiency in comparison with hand sowing in rows.

  3. There were 25–35% of seeds saved, and distribution and quality of seedlings were better in the case of single-seed sowing as compared with hand sowing.


  1. Fonder W. 2006. Realizacja Programu zachowania lesnych zasobów genowych i hodowli selekcyjnej drzew lesnych w Polsce na lata 1991-2010. [Realization of the program of the forest gene resources protection and selection breeding of forest trees in Poland during 1991–2010]. [In:] Elements of genetics and selection breeding of forest trees, ed. J. Sabor. CILP, Warszawa, 537-557 [in Polish].

  2. Grzywacz A. 2000. Stan i potrzeby w zakresie mikoryzacji sadzonek drzew lesnych w Polsce [State and needs of mycorrhization of forest planting stock in Poland]. Postępy Techn. w Lesn. 76, 5-15 [in Polish].

  3. Kowalski S. 2000. Znaczenie mikoryzy dla drzew lesnych oraz problemy zwiazane z projektem wprowadzania polskiej, kompleksowej technologii mikoryzacji. [Importance of mycorrhiza for forest trees and problems connected with introduction of the Polish technology of mycorrhization]. Postępy Techn. w Lesn. 76, 16-23 [in Polish].

  4. Kowalski S. 2005. Stosowana mikoryzacja sadzonek w szkółkach otwartych. [Planting stock mycorrhization used in open forest nurseries]. Biblioteczka lesniczego, zeszyt 221, Warszawa [in Polish].

  5. Kowalski S., Walczyk J., Tylek P. 2005. Single-seed sowing in the treatment of controlled mycorrhization of Scots pine [Pinus sylvestris L.] grown on the peat substratum in channels. Electronic Journal of Polish Agricultural Universities, Volume 8, Issue 1.

  6. Walczyk J. 2006. Mechanizacja prac lesnych w ochronie bioróżnorodnosci. [Mechanization of forest works in protection of biodiversity]. Elements of genetic and selection breeding of forest trees, ed. J. Sabor. CILP, Warszawa, 473-483 [in Polish].

  7. Walczyk J., Tylek P. 2004: Sowing Scots pine seed with a modified single-seed seeder under controlled conditions. Electronic Journal of Polish Agricultural Universities, Volume 7, Issue 2.

  8. Walczyk J., Tylek P. 2005a. Mechanizacja mikoryzacji i siewu precyzyjnego nasion w inspektach. [Mechanization of mycorrhization and precise sowing in frames]. Mobilné energetické prostriedky – Hydraulika – Zivotné prostredie – Ergonómia mobilnych strojov. Technická Univerzita vo Zvolene, 292-299 [in Polish].

  9. Walczyk J., Tylek P. 2005b. Mechanizacja produkcji w szkółkach gruntowych mikoryzowanych sadzonek na potrzeby zalesień gruntów porolnych. [Mechanization of production of mycorrhized planting stock in open field nurseries for needs of afforestation of former farmland]. Inżynieria Rolnicza nr 10 [70], 403-409 [in Polish].


Accepted for print: 20.12.2006

Józef Walczyk
Department of Forest Works Mechanization,
Agricultural University of Cracow, Poland
29 Listopada 46, 31-425 Cracow, Poland
email: rlwalczy@cyf-kr.edu.pl

Paweł Tylek
Department of Forest Work Mechanisation, University of Agriculture in Krakow, Poland
29 Listopada 46
31-425 Kraków

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.