Conclusions

Global climate change caused by anthropogenic GHG emissions is already affecting weather patterns including temperatures and rainfall. CA that consists of minimal soil disturbance, permanent ground cover and crop rotations is a management system that can alleviate some of the effects of climate change. CA results in healthier soils, both physically and biologically, and this in turn improves nutrient cycling and crop growth. Water infiltration and soil penetration by roots is increased allowing crops to better adapt to lower rainfall and make better use of irrigation water. Water and wind erosion is also reduced by CA since the soil surface is protected from erosion and water runoff is lowered as more water enters the soil profile. CA creates soils and production systems more resilient to climate variation and risk. Agricultural production is one contributor to GHG emissions including CO2, CH4 and N2O, the three main gases influencing global warming. In fact, agriculture is a major contributor to CH4 and N2O emissions, two gases with greater warming potential than CO2, although emitted at lower concentrations. CA can mitigate these GHG emissions. CH4 is a by-product of rice cultivation under flooded conditions. Growing rice with less water and adopting CA practices can reduce CH4 emissions. However, care has to be taken with fertilizer management to minimize N2O emissions that can increase under the resulting aerobic conditions. CA can also substantially reduce CO2 emissions through reduced diesel use and potentially increase the sequestration of C in the soil. Therefore, CA not only helps crops adjust to changes in climate but also helps reduce GHG emissions. At present just over 105 million ha of land worldwide uses zero tillage in agriculture. Not all of it is CA but it still impacts positively in the global climate change scenario. In order for this acreage to increase attempts are needed to expand adoption through better extension systems, farmer knowledge and making suitable equipment available to farmers. Much more integrated research and development is needed to develop the fundamental knowledge base for CA as well as to fine tune CA to specific locations and identify suitable germplasm, fertility management, weed control and control of other biotic factors to move this technology onwards. Because of the multi-faceted nature of CA technology development and extension, activities should be concentrated in a few defined locations representative of specific farming systems rather than having lower intensity efforts on a wide scale. Scaling up can then occur from these hubs or focal points by using the farmers and fields as demonstrations to other farmers in surrounding areas.

0 0

Post a comment