Optimizing Corn Production and Reducing Nitrate Losses with Water Table Control‐Subirrigation

Abstract

Water table control‐subiriggation (WTC) systems have increased crop production and improved water quality; however, the relationship between N management, water table depths, and corn production has not been well defined. We hypothesized that optimizing water table depth would increase corn (Zea mays L.) growth, improve N fertilizer efficiency, and reduce NO‐3 losses. A greenhouse incubation study with three water table depths (30, 60, and 80 cm) and four N rates (0, 0.7, 1.4, and 2.1 g N plant‐1) was conducted using undisturbed soil columns (Fox sandy loam, Typic Hapludalf) planted to corn. The 30‐cm WTC treatment had the greatest NO‐3 loss through tile drainage (715 µg N column‐1). The 60‐cm WTC treatment reduced these losses by 54%. Nitrate losses through tile drainage were proportional to drainage volume, which followed the order 30 cm > 60 cm > 80 cm WTC. The 60‐cm WTC treatment increased crop yields (95 g plant‐1) compared with the 30‐cm (68 g plant‐1) and 80‐cm WTC (18 g plant‐1) treatments at the optimal N rate of 1.4 g N plant‐1. After the first simulated rainfall event, N2O production was increased by 12.7 times with the 30‐cm WTC treatment (825 µg N column‐1 d‐1) compared with the 60‐ and 80‐cm WTC treatments. Water stress imposed by the 80‐cm WTC treatment limited crop growth, N uptake, leaching, and N2O emissions. However, up to 28% of added N (664 mg N column‐1) remained in the soil after corn was harvested from the 80‐cm WTC treatment, which would be susceptible to leaching between cropping seasons.

Environmental and Agronomic Implications of Water Table and Nitrogen Fertilization Management

“…Raising the water table by subirrigation increases soil saturation and restricts O 2 diffusion in soil pores, thus creating reducing conditions that promote NO − 3 losses by denitrification. Drury et al (1997) reported that a SI system reduced NO − 3 concentration in tile drainage water by 25% compared with a free drainage (FD) system. Similarly, Jacinthe et al (1999) estimated a 40% reduction in soil NO − 3 due to denitrification in SI plots compared with FD plots.…”

Olive oil mill wastewater for soil nitrogen and carbon conservation

“…The effective incorporation of OC into soils is lower than 50% (McCracken et al, 2002). Nevertheless, irrigation with diluted OOMW and water bubbled with CO 2 , could improve the retention capacity of water, nitrates, and other soil nutrients (Drury et al, 1997;Neilsen et al, 1998).…”

Nutrient Balance and Use Efficiency in Sandy Soils Cropped with Tomato under Seepage Irrigation

“…This occurrence may have facilitated nutrient movement in the bed and eventual loss from the root zone once nutrients reached the bottom layer, particularly NO^^-N and K ( Fig. 2a; Drury et al, 1997;Zeng and Brown, 2000). This could explain why TN¡ in the soil increased during 6 to 8 WAP, then dropped considerably at 10 WAP in the spring season concurrently with the fluctuation ofthe volumetric water content, while TNj in the bed steadily decreased with time in the winter season (Fig.…”