Facilitating Organic Soybean Cultivation under Cool Temperate Climate Conditions.
T. Haase*, H. Schulz, A. Mindermann and J. Hess
Department of Organic Farming and Cropping Systems, University of Kassel, Nordbahnhofstrasse 1A, D-37213 Witzenhausen, Germany.
*
Background:
Soybean (Glycine max) may be a promising crop for organic cropping systems due to its ability to fix nitrogen from the atmosphere and because of its relatively high protein concentration as compared with other grain legumes such as field peas and faba beans. However, under climate conditions of Germany (comparable to the climate prevailing in some regions of Canada), the average crop heat unit during the growing season may be too low for most available cultivars. As a consequence, physiological maturity cannot generally be expected to be reached in each growing season by each cultivar. Due to soybean’s relatively slow early canopy development many weed species may have a competitive advantage and soybean cultivation may require excessive weed management. Therefore, and because air and, consequently, soil temperature in early spring can also be very variable, the question arises if an early or a later date of sowing is preferable in order to promote early crop development less hampered by strong weed infestation. On sites where soybeans have never been cultivated before, treating seeds with
Bradyrhizobium japonicum just before sowing is obligatory. There are several products on the market, however, there are still no experiences gained under organic field experimental conditions as to their efficacy, i.e. their effect on nodulation, crop growth and yield as compared with no seed treatment.
Project Overview:
Three experiments were set up and conducted in 2011 at the Hessische Staatsdomaene Frankenhausen (51.4 N; 9.4 E; 698 mm; 8.5°C mean), the organic (since 2001) research farm of the University of Kassel, Germany. Soil type of the experimental field (preceding crop: beet root) was a Haplic Luvisol; soil texture a silt loam. The field was ploughed in October 2010, and soil prepared with a rotary hoe (March, 28) and a finger weeder (April, 11) in order to reduce weed emergence after sowing. Just before sowing soybeans (65 germinable seeds/m2) the experiments’ land was prepared with a rotary hoe (April, 18).
Experiment 1 was a cultivar trial with 16 different soybean cultivars (different maturity groups) in four replications, experiment 2 a two-factorial trial with factor cultivar (cv. ‘Aveline’, cv. ‘Gallec’) and factor date of sowing (April 19, 26 and May 2). Experiment 3 was a two-factorial trial with factor ‘cultivar’ (1. cv. Merlin’; 2. cv. ‘Protina’; 3. cv. ‘Bohemians’) and factor seed treatment (1. control; 2. Radicin No. 7; Force 48; HiStick; 5. Biodoz Rhizofilm). All experiments were conducted with four field replications. Amongst other parameters we assessed the date of emergence, phenological plant development, maturation, thousand-kernel weight, soybean yield at 91% dry matter and protein concentration (in % DM).
Soybean yield: Results of the first experimental season (2011) indicate the different yield potential of the cultivars tested. Average soybean yield of all 16 cultivars examined was 2.5 t/ha, highest yield (3.2 t/ha) was assessed for the Austrian cv. ‘ES Mentor’, lowest yield for the German cv. ‘Petrina’ (1.5 t/ha). In EXP2, date of sowing did not affect yield significantly, whereas yield differed considerably between cultivars (cv. ‘Klaxon’: 2.5 t/ha; cv. ‘Gallec’: 3.1 t/ha). In EXP3, soybean yield (mean of the 3 cultivars tested) decreased from 2.9 t/ha (Biodoz Rhizofilm), 2.7 t/ha (HiStick and Force48, respectively), 1.9 t/ha (Radicin 7) and 1.7 t/ha (control). These results show the importance of using seed treatment with B. japonicum and the relevance of the product chosen.
Acknowledgments: The financial support of the project by the Federal Office for Agriculture and Food is gratefully acknowledged.
Winnipeg, Manitoba February 21-23, 2012
Canadian Organic Science Conference and Science Cluster Strategic Meetings
111
Grain Yield, Yield Structure and Quality of Organic Winter Wheat as Affected by Row Width and Seeding Density.
T. Haase*, A. Mindermann and J. Heß
Department of Organic Farming & Cropping Systems, University of Kassel, Nordbahnhofstrasse 1A, D- 37213 Witzenhausen, Germany.
*
Background:
Winter wheat (Triticum aestivum) is an important crop plant for many organic farmers, both in Canada and Germany. The economic return of winter wheat with approved baking quality is usually higher than for other cereal crops. Under low-input or organic farming conditions optimum stand densities can generally be expected to be lower than in conventional farming systems. Moreover, with limited nitrogen availability wheat stand density finally may have a major impact on grain protein concentration and therefore the suitability of grains for bread production. Farmers are sometimes paid a surplus if the grains exceed a certain protein threshold. On the other hand, some traders reject wheat grain lots with a too low protein concentration. As a gramineous crop species stand density of wheat may respond strongly to the numbers of seeds sown by either increasing or limiting the number of tillers and - at later crop growth stages - the number of ears per area. At a given seeding density, the distance between individual rows chosen may further affect the above-mentioned agronomic parameters and finally grain yield and quality.
Project Overview:
We conducted a two-factorial field experiment in a randomized block design with three replications at the certified organic research farm of the University of Kassel (51.4 N; 9.4 E; 698 mm; 8.5°C mean) on a Haplic Luvisol derived from Loess over three successive seasons (2009- 2011) in order to examine four different seeding densities (100, 200, 300, 400 seeds/m²) and five different row widths (37.5 - 28.1 - 18.8 - 12.5 - 37.5/12.5 cm) with three replications using cv. Achat, a high-protein
baking wheat cultivar. Crop emergence tillers/m2, ears/tiller, grains/ear and thousand kernel weight were assessed and the number of ears/m2 was calculated from the former two parameters. Protein concentration in grain was calculated from nitrogen concentration determined according to the method by Dumas multiplied by 5.7. Results from three experimental seasons will be presented at the conference. For the parameters ears/m2, grain yield (t/ha at 86% dry matter), 1000-kernel mass (g) and protein concentration, the year consistently had the most marked effect (Table).
Additionally, for the number ears/m2 an interaction of both row width and seeding density with the year was established, while as a main factor only row width was significant. Only factor year had a statistically significant effect on 1000-kernel mass Grain yield responded to the seeding density, but response also depended on the year (2-fold interaction). Grain protein concentration was also affected by seeding density (Table).
2009 2010 2011
1000-kernel mass [g] 39.2 44.2 54.8 Grain protein concentration [%] 9.87 9.04 10.90
Seeding density 2009 2010 2011 100 5.17 4.69 5.33 200 5.78 4.91 5.82 300 5.99 4.90 6.01 400 6.05 4.77 5.99 Seeding density 100 200 300 400 9.92 9.86 Grain yield [t/ha]
Grain protein concentration [%] 10.07