In this article we review how different management technologies like integrated nutrient management, tillage practices, mulching, addition of clay, surface compaction, conservation tillage, use of polymers, etc. can favourably modify the soil physical properties like bulk density, porosity, aeration, soil moisture, soil aggregation, water retention and transmission properties, and soil processes like evaporation, infiltration, run-off and soil loss for better crop growth and yield.

We use the GLOMAP global aerosol model evaluated against observations of surface particulate matter (PM2.5) and aerosol optical depth (AOD) to better understand the impacts of biomass burning on tropical aerosol. To explore the uncertainty in emissions we use three satellite-derived fire emission datasets (GFED3, GFAS1 and FINN1) in the model, in which tropical fires account for 66–84 % of global particulate emissions from fire. The model underestimates PM2.5 concentrations where observations are available over South America and AOD over South America, Africa and Southeast Asia.

Precipitation associated with the South Asian summer monsoon has decreased by approximately 7% since 1950, but the reasons for this are unclear. Now research suggests that changes in land-cover patterns and increased emissions from human activities have contributed to this weakening, which is expected to continue in the coming decades.

Come winter, and the air quality in northern India begins to deteriorate. A thick blanket of smog (mixture of smoke and fog) engulfs the National Capital Region which reduces visibility and gives a tough time to commuters.