The impact and interaction of crop year and certain agrotechnical elements (sowing date, fertilisation, irrigation) on pea yield was observed on chernozem soil in a multifactorial long-term experiment. Examinations were carried out in 2011, 2012 and 2014. The performed research showed that in the favourable crop years of pea production, the amount of precipitation during the months before the growing season (October-February) is 200 mm, while rainfall between May and June is between 60–80 mm per month. Based on the obtained examination results, the main agrotechnical element is sowing date. The maximum yield of pea was 4400–5200 kg ha-1 in the early showing season (mid-March), while it was 3000–4000 kg ha-1 in the late showing season (mid-April), depending on the given crop year. The water use efficiency (WUE) of pea was between 14.5–25.0 kg mm-1 in 2011, 19.6–20.5 kg mm-1 in 2012 and 13.3–28.2 kg mm-1 in 2014. The late sowing date and incomplete nutrient supply decreased the WUE of pea. The yield surplus of pea caused by irrigation was between 160–1300 kg ha-1, depending on the sowing date and fertiliser treatment (2011). A close interaction was shown between the water and nutrient supply and yield of pea production.

The yield increasing impact of fertilisation was relatively moderate in the case of pea (700–1500 kg ha-1 yield surplus) and yield surplus was not affected by the given crop year. Crop year significantly affected the optimum N+PK dose of pea (N140+PK in 2011, N105+PK in 2012, N70+PK in 2014) and the efficiency of fertilisation (yield for 1 kg NPK: 9–12 kg, 17–19 kg and 17–24 kg in 2011, 2012 and 2014, respectively in the Nopt+PK treatments).

The performed research showed that the negative effect of sowing date, the main agrotechnical element, on yield (late sowing date) could be partially compensated with proper nutrient and water supply. With optimised agrotechnics on chernozem soil, pea yields of 4.0–5.0 t ha-1 could be safely obtained in the majority of crop years.

Keywords: pea, yield, crop year, sowing date, fertilisation, irrigation