Submitted to: Proceedings of the Central Plains Irrigation Conference
Publication Type: Proceedings
Publication Acceptance Date: February 13, 2012
Publication Date: February 21, 2012
Citation: Bordovsky, J.P., Cranmer, A., Colaizzi, P.D., Lamm, F., Evett, S.R., Howell, T.A. 2012. Investigating strategies to improve crop germination when using SDI. Proceedings of the Central Plains Irrigation Conference. February 21-22,2012, Colby, Kansas. p.117-132. Interpretive Summary: Subsurface drip irrigation (SDI) applies irrigation water very slowly and in small amounts in the crop root zone. The water is applied by plastic emitters that are attached to plastic tubing. The tubing is buried several inches below the soil surface. This reduces evaporation losses, weeds, and crop disease, and can increase the soil temperature compared with sprinkler and flood irrigation. All of these factors can result in greater crop yield and greater crop water productivity. However, crop germination can be difficult with SDI if the soil is dry from lack of rainfall. In this case, water must move from the drip emitter to the seed bed before the crop can germinate. The movement of water can be impeded by soil cracks, which form when the soil is dry. This paper reviews several methods that may overcome this limitation. Soil amendments can be added to enhance the movement of water. Drip tubing can be installed at shallower depths. Seeds can be planted closer to the drip emitters. Water can be applied in different amounts and at different times before the crop is planted.
Technical Abstract: As the nation's population increases and available irrigation water decreases, new technologies are being developed to maintain or increase production on fewer acres. One of these advancements has been the use of subsurface drip irrigation (SDI) on field crops. Research has shown that SDI is the most efficient in-season water application method available to producers, especially under deficit irrigation (Bordovsky and Porter, 2003; Colaizzi et al., 2009). For certain soils, one of the inherent problems with SDI is seed germination during periods without rainfall. This paper summarizes efforts to improve germination when irrigating with SDI at the agricultural research centers at Halfway, Texas; Bushland, Texas; and Colby, Kansas. These efforts were broadly categorized in terms of soil amendments, drip lateral installation depth, row geometry, and preplant irrigation timing and amounts.