Legume–cereal intercropping systems offer promising solutions for sustainable agriculture, yet their performance is influenced by environmental and management factors. This study evaluated the productivity and nutrient dynamics of field pea ( Pisum sativum L.), lentil ( Lens culinaris Medik.), and chickpea ( Cicer arietinum L.) grown in pure stands and relay-row intercropping with winter rye ( Secale cereale L.) over three growing seasons (2022–2024) in central Lithuania. The relay-row intercropping system consisted of two rows of winter rye alternating with one row of legumes, maintaining a seed ratio of 1:0.3 (legume/rye). Legume biomass and grain yield were significantly affected by interannual climatic variability, with peas consistently producing the highest yields. Relay intercropping reduced legume yield, particularly under unfavourable conditions, when winter rye gained a competitive advantage. Competition was most pronounced at early growth stages (BBCH 39), as indicated by negative RCI values, while at maturity this effect diminished. Nutrient accumulation patterns differed among species: chickpeas accumulated more phosphorus and potassium, lentils accumulated more nitrogen, and peas showed the highest relative NPK yield in favourable years. Intercropping did not significantly alter nutrient concentrations in biomass; however, under unfavourable conditions, increased total nitrogen in mixtures was mainly associated with rye biomass rather than enhanced biological nitrogen fixation. These findings highlight the importance of optimizing intercrop design—including cultivar selection, seeding ratios, and spatial configuration—to balance competition and complementarity and improve legume productivity in relay systems with winter rye. • In both cropping systems, peas achieved the highest grain, and biomass yields among the studied legumes. • Relay intercropping with winter rye reduced legume yields, particularly in unfavourable years. • Peas and chickpeas accumulated more NPK than lentils, especially under favourable conditions. • Optimization of crop selection, seed rates, and spatial arrangements is crucial for improved intercrop performance.
Šarūnaitė et al. (Tue,) studied this question.