Tag Archives: Sowing date

xxx M. Toom, L. Talgre, P. Pechter, L. Narits, S. Tamm and E. Lauringson
The effect of sowing date on cover crop biomass and nitrogen accumulation
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The effect of sowing date on cover crop biomass and nitrogen accumulation

M. Toom¹²*, L. Talgre², P. Pechter¹, L. Narits¹, S. Tamm¹ and E. Lauringson²

¹Estonian Crop Research Institute, J. Aamisepa 1, EE48309 Jõgeva, Estonia
²Estonian University of Life Sciences, Kreutzwaldi 1, EE51014 Tartu, Estonia
*Correspondence: merili.toom@etki.ee

Abstract:

Cover crops are important tools for reducing nitrogen (N) leaching from the soil and improving the nutrition of cash crops. In northern regions with short autumns it is important to maximise the growing season of cover crops to achieve sufficient biomass and N accumulation. The objective of the study was to evaluate the biomass and N accumulation of cover crops at different sowing dates in August.
Field experiment at Estonian Crop Research Institute was conducted in 2017 and 2018 with white mustard (Sinapis alba L.), phacelia (Phacelia tanacetifolia Benth), buckwheat (Fagopyrum esculentum Moench), berseem clover (Trifolium alexandrinum L.), field pea (Pisum sativum L.) and faba bean (Vicia faba L.). Cover crops were sown on August 3, 8, 14 and 18 in 2017 and August 3, 8, 13, 17 and 23 in 2018.
The two year experiment showed that biomass and N accumulation of cover crops were reduced with delayed sowings, but the reduction mainly depended on cover crop species.
White mustard, field pea and faba bean accumulated significantly higher amount of biomass and N than phacelia, buckwheat and berseem clover at all sowing dates in both years. Because of a rapid decrease in biomass, the optimum sowing time for phacelia and buckwheat should not be later than middle of August. In both year berseem clover produced the modest amount of biomass and therefore more suited as spring sown cover crop in Estonian conditions.

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230-242 E. Samadzadeh Ghale Joughi, E. Majidi Hervan, A.H. Shirani Rad and GH. Noormohamadi
Fatty acid composition of oilseed rapeseed genotypes as affected by vermicompost application and different thermal regimes
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Fatty acid composition of oilseed rapeseed genotypes as affected by vermicompost application and different thermal regimes

E. Samadzadeh Ghale Joughi¹, E. Majidi Hervan¹*, A.H. Shirani Rad² and GH. Noormohamadi¹

¹Department of Agronomy, Science and Research Branch, Islamic Azad University, Tehran, Iran
²Department of Agronomy, Seed and Plant Improvement Institute, AREEO, Karaj, Iran
*Correspondence: majidi_e@yahoo.com

Abstract:

Vegetable oils with a high relative amount of unsaturated fatty acids are of great significance for human health. Hence, in a 2-year factorial split plot experiment, the effects of different sowing date (optimum (October 17) and late (October 27)), vermicompost (0 and 20 ton ha-1) and genotypes (BAL104, DIE710.08, BAL102, FJL330, FJL290 and Okapi) on the fatty acid composition of rapeseed were evaluated. Rapeseed genotypes and the combination of sowing date and vermicompost application were randomized to sub and main-plots, respectively. The present results revealed that yield, oil percentage and fatty acids composition is affected by sowing dates along with genotypes. However, the unsaturated fatty acid, eicosanoic acid was not affected by interaction sowing date and genotype. Vermicomposting increased the yield, oil percentage, oleic, linoleic and linolenic acids and decrease erucic unsaturated fatty acid. The FJL290 and BAL102 genotypes produced the highest values of grain yield (5,853 and 5,763 kg ha−1, respectively), oil percentage (43.98% and 43.85%, respectively), linoleic % acid (20.51 and 20.37% respectively), oleic % acid (65.23 and 64.93% respectively) and linolenic % acid (7.20 and 7.09% respectively) in comparison to the other genotypes, when they were sown at the optimum sowing date. The FJL290 and BAL102 also accelerated their growth period at the late sowing date. Consequently, oleic, linoleic and linolenic acids had the highest direct and indirect effect influence on grain oil percentage indicating their importance as selection criteria to improve yield and oil quality of rapeseed. Concluding the combination of sowing date, vermicompost and FJL290 and BAL102 lines may be the most favourable cropping strategy for rapeseed production in Iran.

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