Effects of drainage water management on crop yields in North Carolina

Abstract

Research studies on a wide range of soils, crops, locations, and climates have shown that drainage water management (DWM), or controlled drainage (CD), can be used to substantially reduce the loss of nitrogen (N), and in some cases, phosphorus (P) from drained agricultural lands to surface waters. The adoption and widespread application of DWM depends on a variety of factors including its impact on crop yields. This paper presents results from a long term field study on the effect of DWM or CD on crop yields in a threecrop, two-year corn/wheat-soybean rotation. Yields were measured on replicated field scale plots under CD and conventional or free drainage (FD) treatments for a total of 18 crops on two experimental sites during the period from 1990 to 2011. Data were collected on 7 corn (Zea mays L.) crops, 5 wheat (Triticum aestivum L.) crops, and 6 soybean (Glycine max L.) crops. Controlled drainage had no significant effect on yields of winter wheat, which in North Carolina is grown in the wettest, coolest part of the year. Controlled drainage increased corn yields compared to FD in all seven years. The average yield increase for corn was 11%. Controlled drainage also increased soybean yield in all years with an average increase of 10% compared to FD. Such yield responses will promote the application of DWM, which will result in both economic and environmental benefits.

Satellite and in situ derived corn and soybean biomass and leaf area index: Response to controlled tile drainage under varying weather conditions

“…In a 5-7-year study, for example, Poole et al (2013) reported an average yield increase of about 10% for corn and soybean, yet no effects were observed for wheat. In all the years of that study, the effect of CTD was always positive for corn and soybean, but for wheat the effect was negative in 3 of the 5 study years.…”

Modeling nitrate removal in a denitrification bed

“…The smaller drainage discharge with controlled drainage induces longer bed hydraulic retention times that lead to greater nitrate removal. In the Midwest USA, a three-chamber inlet control structure is commonly used in bed installations to provide the means to implement controlled drainage which may provide an incentive of increased crop yield over the long term (Ghane et al, 2012;Poole et al, 2013). Woli et al (2010) found integration of controlled drainage with a denitrification bed to be very effective in nitrate removal.…”

Effect of Drainage Water Management on Nitrate Nitrogen Loss to Tile Drains in North Carolina

“…about 4 mg L -1 by the end of the year. The high concentrations were probably due to the sequence of events during 1993 when severe drought reduced corn yields to less than 60% of the average yield for the study (Poole et al, 2013). Much of the fertilizer N applied for the corn crop was not taken up by the crop and remained in the soil profile.…”

“…[b] Data only through 14 September 1993, corn. yields by 11% and average soybean yields by 10% but had no significant impact on yields of winter wheat (Poole et al, 2013). The measured annual NO 3 -N exported in the drainage water from each plot for each year (table 6) was added to the N exported in the harvested grain (table 7) to give the total N exported from the treatments by year (table 8).…”

“…The objective of this research was to experimentally determine the effects of CD on crop yields and N losses in drainage water over an extended period. Effects of CD on crop yields for a three-crop, twoyear rotation of corn-wheat-soybean were reported by Poole et al (2013). This article reports the effect of CD on drainage volume and nitrate-N losses based on nine years of observations on replicated plots in eastern North Carolina.…”