Microclimate and grain yield of soybean (Glycine max) under different environments

Field experiments were conducted at Punjab Agricultural University, Ludhiana during Kharif seasons of 2009 and 2010 to evaluate the effect of mulching on microclimate and yield of soybean under different sowing environments. Soybean (variety SL-525) was sown on two different dates viz. 10 June and 25 June. Wheat straw mulch was used to alter the microclimate of the crop. The application of straw mulch was found to decrease the maximum temperature while it increased the minimum temperature inside the crop canopy. Difference between the maximum temperature inside the canopy under mulched and non mulched condition ranged from 0.5–3.0°C whereas for minimum temperature difference was between the range of 1.0–3.5°C. Photosynthetically active radiation interception was more under mulched plots as compared to non mulched plots. There was 5.5 to 10.6 per cent increase in the seed yield under mulched conditions but seed yield improvement under mulch was less in year 2009 due to more rainfall.