Effect of rice (Oryza sativa) straw mulching on the performance of rapeseed (Brassica campestris) varieties in rice-rapeseed cropping system.

An experiment was conducted at Meghalaya, during 2006–08 to study the effect of rice straw mulching on growth, yield attributes and yield of different rapeseed (Brassica campestris L.) varieties, namely ‘M 27’, ‘TS 38’ and ‘Sikkim Sarson’. The plant height of rapeseed increased by 7.2% at harvest due to rice straw mulching @ 5.0 tonnes/ha over the non-mulching and it was highest (96.88 cm) in ‘TS 38’. Lower values (–2.9°C) of canopy air temperature difference were recorded in the mulch treatment than under control (–2.3°C). Mulching resulted in storage of 2.0% more soil moisture in the root zone of the crop over the unmulched control, indicating better microclimate for crop growth and development. Leaf area index was higher in ‘TS 38’ and in mulching treatment. Number of siliquae/plant (24.6%), seeds/siliqua (17.6%) and seed yield (35.4%) increased due to mulching over the non-mulching. The varieties differed significantly with respect to 100-seed weight and it was highest (0.37 g) in ‘TS 38’. Highest seed yield was obtained in ‘TS 38’ (1.51 tonnes/ha), followed by ‘M 27’ (1.46 tonnes/ha) and significantly superior over the ‘Sikkim Sarson’ (0.97 tonnes/ha).