Submitted to: Annual Southern Conservation Tillage Conference for Sustainable Agriculture
Publication Type: Proceedings
Publication Acceptance Date: 5/15/2006
Publication Date: 6/15/2006
Citation: Colaizzi, P.D., Evett, S.R., Howell, T.A. 2006. Crop emergence with alternative SDI designs in a Pullman Clay Loam soil. In: Proceedings of the 28th Annual Southern Conservation Systems Conference, June 26-28, 2006, Amarillo, Texas. p. 16. Interpretive Summary: The Pullman clay loam soil, which is commonly cultivated in the Texas High Plains, tends to develop large cracks upon drying out. This often occurs when precipitation before planting crops is sparse, making it difficult to germinate a crop using subsurface drip irrigation (SDI). Soybean emergence and final yield were compared for two different bed designs for SDI. In one design, drip laterals (lines of drip irrigation tubing) were installed in alternate furrows between standard beds containing a single planted row; in the second, drip laterals were installed in wide beds containing two planted rows. The wide bed design resulted in better crop germination and establishment because the plant rows were closer to the drip laterals; however, final soybean yields were not significantly different. This research will continue for grain corn, which may have different early season emergence and final yield responses.
Technical Abstract: We compared soybean emergence and yield for different bed designs for subsurface drip irrigation (SDI). The bed designs consisted of standard beds with drip laterals installed in alternate furrows, and wide beds with drip laterals centered in the bed between two plant rows. Both designs result in the same number of laterals and planted rows per unit area; however, planted rows are closer to the drip laterals for the wide bed design. This may result in better crop germination compared to the standard bed design if preplant precipitation is inadequate to germinate the crop. For each bed design, lateral burial depth was 6-, 9-, and 12-in (15-, 22-, and 30-cm), and irrigation rates were 33, 66, and 100% of full crop evapotranspiration (ETc). Better soybean emergence resulted using the wide bed design regardless of lateral installation depth; however, no significant differences were observed for final grain yield, possibly due to less competition for water and nutrients when plant populations were sparser. Plans are to repeat this experiment for grain corn, which may have a different emergence and yield response.