Effect of mulch, no-tillage and no-fertiliser as sustainable practices on soil organic carbon and carbon dioxide emission

The study seeks to investigate the compounding effects of various practices such as mulch, no-tillage, tillage and nitrogen based fertilizer on CO2 emission and soil organic carbon (SOC) in three successive crop cycles in the region of Vacoas, Mauritius. Nitrogen based fertilizer (ammonium sulphate) was applied at 120 kg/ha to its corresponding treatment, and maize mulch was applied as full coverage (24 t/ha). Three treatments: Mulch (M), Fertilizer (F), Tillage (T), were tested at 2 levels each, and replicated 3 times. The 2 levels were mulch-no mulch, fertilizer-no fertilizer and tillage-no tillage. Results have shown a correlation between CO2 and pH, where increase in CO2 flux was due to addition of fertilizer. Furthermore, application of mulch did not increase SOC in the short term. A negative correlation was equally found between available phosphorous and temperature which was attributed to the interactions that exist between temperature, photosynthesis and nutrient availability. The present study revealed that reduction in CO2 emission and increase in soil fertility can be achieved at farmer level by adopting mulching and no-till. These practices are both economical and farmer friendly. This is a first study of such kind in the soils of Mauritius, a volcanic Island in the Indian Ocean latitude 20° 17′ 53″ South and longitude 57° 28′ 42″ East.