This chapter considers various project alternatives, and the associated environmental as well as social concerns.
The ‘no-project’ alternative is not acceptable since in that scenario, a considerable amount of irrigation water will continue to be wasted. As described in Section 1.1, the irrigation sector in the Country suffers from among other factors low surface water delivery efficiency as well as wasteful on-farm water use, and only 35-40 percent of the irrigation water reaches from the canal head to the crop root zone. Pakistan relies upon its irrigation network for 90 percent of its food production and 25 percent of its GDP. In addition, the Country’s agriculture sector provides two-third of employment and 80 percent of exports. With rising population and the associated increasing pressure on food and other commodities, and decreasing water availability in the rivers, improving the water delivery efficiency is vitally important to enhance the irrigation productivity that will in turn increase the productivity of agriculture sector.
Flood irrigation has been the traditional method in the Country for ages. In this method, the entire cultivation field is flooded with the irrigation water. This method is time consuming and hence labor intensive, highly inefficient in terms of water usage, and also results in other problems such as increased vulnerability to pest attacks and proliferation of weeds, in turn resulting in the increased need of pesticides and weedicides. The high efficiency irrigation methods proposed under the Project address all of these problems, in addition to achieving enhanced yields and productivity of the farms. As already mentioned in Section 1.1, these high efficiency irrigation systems typically reduce input costs by 20-35 percent, increase yields by 20-100 percent, lower irrigation labor up to 30 percent, diversify cropping patterns, and save up to 75 percent water.
It is clear from the above comparison that the high efficiency irrigation methods are the preferred option for irrigating the cultivation fields in the Country.
The high efficiency irrigation methods generally result in the reduced need of farm inputs such as fertilizers, pesticides, fungicides, and herbicides, as mentioned above. The controlled irrigation generally results in reduced vulnerability of the crops to the pest attacks and reduced proliferation of weeds, in turn resulting in reduced need of pesticides and herbicides. In addition, fertigation (i.e., application of fertilizers or other soil additives through the irrigation system) is possible for the high efficiency irrigation systems, such as drip and sprinkler, resulting in enhanced effectiveness of the fertilizers and hence their reduced quantities needed. Similarly, for these high efficiency irrigation systems, chemigation (i.e., application of pesticides, fungicides, and herbicides through the irrigation system) is possible, resulting in enhanced effectiveness of these chemicals and hence their reduced quantities needed. The overall result of the high efficiency irrigation system is therefore a much reduced usage of chemical inputs.
The above mentioned reduced usage of chemical inputs affects the environment and communities in a positive manner. The excessive usage of these chemicals causes contamination of soil and water that may pose health hazards for the nearby communities and may also harm the natural flora and fauna including beneficial insects that are important for functions such as pollination. With the adoption of high efficiency irrigation methods, contamination of soil and water and the associated negative impacts on communities and natural flora/fauna are likely to be reduced.
e.3Alternative Land Leveling Methods
The conventional leveling with the help of tractors or graders is the major alternate to the laser land leveling, which is included in the proposed project. Through the conventional methods, land cannot be leveled with precision, hence the advantages of leveling cannot be fully achieved. Unleveled fields result in improper irrigation, wastage of irrigation water and also require additional farm labor.
On the basis of the above, it is evident that the precision land leveling through laser leveling is a preferred mode of farm leveling.
Environmental and Social Aspects
No major environmental and social aspects are associated directly with the leveling activity. The indirect aspects of the conventional leveling methods include increased water consumption, increased need of pesticides, weedicides, and other chemical inputs. This excessive usage of chemical inputs can potentially contaminate soil and water, which may pose health hazards for the nearby communities and may also harm the natural flora and fauna, as described above as well. It can therefore be concluded that with the help of laser leveling, contamination of soil and water and the associated negative impacts on communities and natural flora/fauna is likely to be reduced.
e.4Alternative Methods of On-farm Water Conservation
The alternatives available for the on-farm water conservation include i) piped conveyance system; re-alignment and brick-lining the entire length of the water course; and re-aligning and improving the water course, but keeping it earthen (ie, without brick-lining). The cost of the first alternative would be prohibitive with marginal benefits compared to the second alternative, and the reduction of water losses will not be substantial in case of the third option. Therefore, the benefit-cost ratio is best for the second alternative, which has been selected for the proposed project.
Environmental and Social Aspects
No major difference exists among the above options in terms of the environmental and social consequences, except that the third option would not fully achieve the objective of water conservation and associated benefits.