Growth and Yielding of Onion Under Conservation Tillage

A field experiment with conservation tillage was set up to study the effect of using cover crops: spring rye (Secale cereale) and vetch (Vicia sativa), and various methods of soil preparation prior to sowing: no-tillage, rotary disk ploughing in the spring, and pre-winter disk ploughing, on the growth and yielding of onion cv. Wolska as compared with conventional cultivation methods.

Sprouting of onion plants was best on those plots where spring rye mulch had been mixed with the soil during pre-winter disk ploughing. Mixing the soil with the biomass of vetch by disk ploughing in the spring reduced the extent of sprouting. Growth of onion plants was best following traditional soil cultivation. On those plots, onion plants were the tallest and produced the most leaves. The soil conservation factor employed by taking advantage of the mulching effect of intercrop plants of spring rye and vetch was found to reduce the total and marketable yields of onion in comparison with traditional cultivation. The most beneficial pre-sowing tillage method for onion was traditional tillage consisting in pre-winter ploughing and soil preparation treatments in the spring, without the presence of a mulching crop. Among the soil mulching plants under comparison, a more beneficial effect on onion yields was produced by the spring rye. As far as conservation tillage is concerned, the best effects were obtained following spring tillage in which rye mulch was mixed with the soil by disk ploughing.