Влияние сроков посева моркови на формирование урожая в условиях мерзлотных почв Якутии

Abstract

In the Nyurbinsky Districtof Yakutia, on permafrost-taiga pale-yellow soil, the experiments were carried out to study the influence of carrot sowing dates on its yieldsand weed infestation. The experimental design included 4 vari-ants with different sowing dates: 1) May 22-25 -control; 2) May 15-18; 3) May 22-25; 4) May 29-31. The carrot sow-ing rate was 4 kg ha; the accounting area of the experi-mental plot was 22.4 m2; there were four replications; the placement of variants was systematic. The research target was the carrot variety Nantskaya released for the Republic of Sakha (Yakutia). The soil of the experimental plot was permafrost-taiga pale-yellow transitional old-arable soil, medium loamy in its particle-size distribution. The experi-ments showedthat early shoots and yield formation result-ed from early spring and under-winter sowing dates (by 6 and 9 days earlier than the control sowing dates, respec-tively); a significant yield gain of root crops as compared to the control variant resulted from the early spring sowing dates (May 15-18) -by 1.27 t ha, or 114% of the yield. The studies allowed concluding that the best sowing dates of carrots in permafrost soils of the cryolithic zone is the early spring period (May 15-18) which ensures the early tech-nical ripeness of root crops (by 9 days earlier than the con-trol), the least weed infestation and high yields (30.2 t ha