Improving soil health and water productivity of lentil (Lens esculentum) sown after lowland rice (Oryza sativa) through appropriate variety and rice residue management

A field experiment was conducted during rainy and winter seasons of 2012–13 in lowland at ICAR Research Complex for NEH Region, Umiam, Meghalaya to identify suitable rice (Oryza sativa L.) and lentil (Lens esculentum Medik.) cultivars and appropriate rice residue-management practices (RRMPs) for enhancing productivity of rice-lentil system and improving soil health. The results revealed that there was no significant effect of rice cultivars on productivity of lentil. However, the yield of lentil was significantly influenced by lentil cultivars and RRMP. Lentil variety ‘IPL 406’ recorded significantly higher yield (1.82 t/ha), water-use efficiency (9.46 kg/ha-mm) and water productivity (3.30 kg/m³) compared to that of ‘DPL 81’. Amongst RRMPs, mulching recorded significantly higher lentil yield (1.87 t/ha), water-use efficiency (9.75 kg/ha/mm) and water productivity (3.40 kg/m³) compared to 20 cm standing stubble and residue removal. Irrespective of rice and lentil cultivars, mulching recorded about 26.7% and 18.7% higher lentil yield than residue removal and 20 cm standing stubble respectively. Available N and K were higher when ‘DPL 81’ grown after rice cultivar ‘Shahsarang 1’ as compared to that under Mendri. Significantly higher available N, K and soil organic carbon were recorded under mulching than 20 cm standing stubble and straw removal. The dehydrogenase activity and soil microbial biomass carbon were significantly higher under mulching than removal and 20 cm standing stubble. Thus, growing of lentil ‘IPL 406’ under mulching @ 5 t/ha after high-yielding varieties of rice ‘Shahsarang 1’ is a viable option for enhancing productivity and WUE under rainfed lowland conditions.