Soybean yield under different tillage systems.

In Poland the soybean is becoming an increasingly more popular crop plant that is valued, among others, for the high nutritional value of its seeds. There are few studies on the effect of tillage systems used for soybean which are carried out in the climatic con- ditions of our country. This proves the need to continue such research. The present study investigated the effect of plough tillage and direct seeding on seed yield and some yield components of two soybean cultivars (Augusta and Aldana) in the climatic conditions of central-eastern Poland. A three-year field experiment was established on lessive soil using a split-block design in four replications. The study showed that cv. Aldana produced higher seed yield by 10.6% compared to the other cultivar; this cultivar was also charac- terized by higher plant density after emergence and before harvest, a higher number of seeds per pod, and higher 1000 seed weight. Seed yield significantly varied depending on the tillage system used. Under conventional tillage, soybean produced 14.7% higher yield than in the case of direct seeding. Compared to plough tillage, no-tillage significantly re- duced plant height and first pod height as well as plant density after emergence and before harvest.