Evaluation of wheat (Triticum aestivum) and legume intercropping under 1:1 and 2:1 row-replacement series system

A field experiment was conducted during the winter season of 1992-93 and 1993-94 at Agricultural Experimental Farm, Giridih, Bihar to evaluate the intercropping systems of legumes, gram (Cicer arietinum L.), pea (Pisum sativum) and lentil (Lens culinaris) with wheat (Triticum aestivum) in 1:1 and 2:1 'row replacement series'. Intercropping systems were assessed on the basis of new indices termed as actual yield loss (AYL) and intercropping advantage (IA). This paper highlights the comparative effectiveness of evaluating the intercropping systems through the existing intercropping indices like LER, RCC, aggressivity. The indices AYL and IA seem to be more appropriate particularly when per plant yield is considered. Intercropping reduced the yield of component crops compared with respective pure stands. Wheat + pea in 1:1 row replacement series gave the highest wheat yield equivalent value (3.02 t h(-1)) followed by wheat + lentil (2.91 t ha(-1)). When the actual sown proportion was considered wheat + lentil (1:1) resulted in maximum An (+0.610) and IA (+0.279) values. This treatment also gave the maximum monetary advantage (Rs 5985.45 ha(-1)).