a1 Indian Agricultural Research Institute, New Delhi-110012, India
A study was made under rainfed (unirrigated) conditions in a subtropical and semi-arid region of northern India during the winter (October–March) seasons of 1980–1 and 1981–2 to evaluate the growth, resource use and seed yield performance of four intercropping systems, namely mustard alone, ⅔ mustard +⅓ chickpea, ⅓ mustard + ⅔ chickpea and chickpea alone grown at 7·5, 15·0, 22·5 and 30·0 plants/m2.
The total economic productivity of intercrop systems was greater than that of either component grown alone. The components of seed yield (number of primary and secondary branches, number of pods, seed weight per plant and weight of seed) increased in mustard where intercropped but the opposite occurred in chickpea. These growth attributes were decreased with an increase in plant population density. The two crop species needed an individual density less than their sole crop optima to form an optimum density when intercropped. A mixture of ⅓ mustard + ⅔ chickpea appeared to be the best system for the rainfed conditions in which these experiments were made and produced greatest yield advantage.
Chickpea grown in ⅓ mustard + ⅔ chickpea combination had greater nodulation with higher dry weight per nodule. A greater leaf area index (LAI) for both the crop species was noted in ⅓ mustard + ⅔ chickpea mixture than were found in other systems. The maximum LAI of mustard and chickpea was attained at 60 and 120 days after sowing respectively and this may be why a lower proportion of mustard plants in the intercrop was more advantageous.
A combination of ⅓ mustard + ⅔ chickpea removed more nitrogen from the soil, had better water use efficiency and comparatively less soil moisture depletion than the sole crop. Soil nitrogen utilization and soil moisture depletion were less at higher densities.
(Revised September 08 1986)
(Received September 08 1986)
p1 Present address: Directorate of Pulses Research (Indian Council of Agricultural Research), Kanpur-208024, India.