Final Remarks

One third of the total primary energy is contributed by straw in sugarcane as a crop. Sugarcane also possesses some characteristics which are very similar to widely used bagasse. This makes it a very good fuel to bagasse supplement. It can contrib­ute to surplus power generation in the mills. For the second generation production of biofuels, straw can be efficiently used. An excellent opportunity is provided in Brazil in order to increase the fast implementation of management system of green cane to increase sugarcane energy performance, sustainability of the production of ethanol, as well as the economics. But its use is incipient, still. This is due to lack in the long-term experience with collection and use of straw along with the uncertain­ties in the processing, storage, and collection costs (Leal et al. 2013).

The benefits imparted by agronomic characteristics are pretty clear, but the quan­tification is difficult although their magnitude is analyzed in different situations. The minimum amount for the assurance of ground protection against erosion has not been estimated. A significant difference is contributed between burned cane, which is in bare soil and unburned cane, with straw mulch on the ground in the water and soil losses. Literature revealed a consistent increase concerning the con­tent of soil carbon in the management of green cane with all straw left in the fields in comparison with burned systems of cane. A wide variation has also been shown in the results as it depends on climate and soil characteristics as well as the history of land use.

It has been noted that straw blanket imparts positive as well as negative impacts on the biota. Positive effects on macrofauna in the soil mainly include ants and worms, whereas the negative one includes increase in population of pests. The effect of inhibition of weed by straw mulch has also been confirmed by several authors for some of the species and has been found neutral for others. This data helped in gath­ering information about the magnitude of different impacts imparted by straw mulch left on the ground after harvesting the unburned sugarcane. This helped in assess­ment of optimum straw that should be left in the field to take advantage of the agro­nomic and industrial benefits. There are many variables that affect various benefits that were included in the evaluation. These variables include soil and climate char­acteristics, local topography, varieties of sugarcane and agricultural practices, etc.

At this time it is not possible to define proper amount of straw that should be left on the ground.

Best approach would be initial concentration on the erosion of soil and dynamics of soil carbon. These are associated with both economic and environmental benefits. Economic benefits include fertility of soil, yield of the crop, and cost of the produc­tion, whereas preservation of natural resource, crop sustainability, and sequestration of carbon are involved in the environmental benefits. Finally, it is significant to pin point the viability of integration of technologies of second generation in future. This involves conventional distillery of sugarcane which increases the yield of biofuel per unit area cropped and the efficiency of energy. This requires the use of straw fraction that results from unburned harvesting of cane.