Advantages and Disadvantages of Subsurface Drip Irrigation

The advantages and disadvantages of subsurface drip irrigation (SDI) as compared to alternative irrigation systems are conceptually discussed. Each category (advantages and disadvantages) is subdivided into three groups: 1) Water and soil issues; 2) Cropping and cultural practices, and 3) System infrastructure issues. The adaptation and adoption of SDI systems into diverse cropping systems, geographical regions, soils and climate depends, to a large extent, on how potential advantages are balanced against potential disadvantages. In some cases, just a few advantages are expressed for a given cropping system, but are expressed so strongly that they provide a good counterbalance to the potential disadvantages. Future research and development will probably add to the list of potential advantages while addressing and reducing the disadvantages. However, this current listing can be used to devise and adapt other possible uses for SDI. Specific examples of SDI use in maize (Zea mays L.), alfalfa (Medicago sativa), almonds (Prunis dulcis), cantaloupe (C. melo) and wastewater applications are discussed with respect to balancing advantages and disadvantages. ADVANTAGES OF SDI The following list should be considered as potential advantages of subsurface drip irrigation (SDI) when properly managed and/or when site conditions and cropping systems allow the advantage to be realized. Additionally, some growers might see an aspect as an advantage, while another might see an aspect as a disadvantage. For example, there are opportunities for improved cultural practices with SDI, while at the same time, there might be fewer tillage alternatives. These advantages may be further subdivided along the lines of water and soil issues, cropping and cultural practices and system infrastructure issues. Advantages related to water and soil issues More efficient water use – Soil evaporation, surface runoff, and deep percolation are greatly reduced or eliminated. Infiltration and storage of seasonal precipitation can be enhanced by drier soils with less soil crusting. In some cases, the system can be used for a small irrigation event for use in germination, depending on dripline depth, flow rate and soil constraints. The inherent ability to apply small irrigation amounts can allow better water-efficient decisions about irrigation events near the end of the cropping season. In widely spaced crops, a smaller fraction of the soil volume can be wetted, thus further reducing unnecessary irrigation water losses. Less water quality hazards – Runoff into streams is reduced or eliminated, and there is less nutrient and chemical leaching due to deep percolation.