Effects of Nitrogen Rate, Irrigation Rate, and Plant Population on Corn Yield and Water Use Efficiency

Abstract

crucial for the survival of agriculture in northeastern Colorado. Improper N and irrigation management are major factors contrib-The relationships of corn yield and nitrate leaching uting to water quality and shortage problems in the Great Plains.with irrigation, N fertilization, and plant population This study was conducted on the Irrigation Research Farm in Yuma, have been extensively investigated. Irrigation effectively CO, from 1998 through 2000 to establish an accurate irrigation and N management system for corn (Zea mays L.) production in the increases corn yield although WUE expressed as corn Great Plains aimed at high yield and water use efficiency (WUE) yield to total water use ratio decreases as irrigation rate simultaneously. A field experiment was conducted on a center-pivotincreases (Stone et al., 1987(Stone et al., , 1993 Hergert et al., 1993). irrigated, well-drained Haxtun sandy loam soil (fine-loamy, mixed, Nitrogen fertilization also increases corn yield when N superactive, mesic Pachic Argiustolls) by using a randomized complete supply by soil is low (Wienhold et al., 1995; Sexton et al., block split-split plot design, with irrigation rates [0.60, 0.80, and 1.00 1996). Nitrogen fertilizer applied at rates higher than the of the estimated evapotranspiration (ET)], N fertility rates (30, 140, optimum requirement for crop production may cause an 250, and 360 kg ha Ϫ1 , including N from soil, fertilizer, and irrigation increase in nitrate accumulation below the root zone water), and plant populations (57 000, 69 000, and 81 000 plants ha Ϫ1 )and pose a risk of nitrate leaching (Linville and Smith, as the main-plot, split-plot, and split-split plot treatments, respectively.

Effect of phenophase based irrigation schedules on growth, yield and quality of baby corn (Zea mays L.)

“…Sundarsingh [7] recorded higher water use and WUE at IW/CPE ratio of 1.0 over 0.5 and 0.75 ratios. However, Mahdi et al [12] opined higher WUE at 1.0 E 0 over 0.6 and 0.8 E 0 .…”

Performance Evaluation of Gated Pipes Technique for Improving Surface Irrigation Efficiency in Maize Hybrids

“…The gated pipe has many advantages: 1) requires small area of land to install the system; 2) reduces the seepage and evaporation losses and better water distribution; 3) low cost and maintenance requirements and 4) can improve human public health by avoiding contact with infected water. [13] reported that the differences between 0.80 ET c and 1.00 ET c treatments were not significant, while the lowest maize growth and yield were obtained from 0.60 ET c treatment. The same authors added that the 0.80 ET c irrigation treatment had the same or even greater WUE than 1.00 and 0.60 ET c .…”

“…However, flooded or very wet soils increase the solubility of minerals and promote nitrogen leaching and the contamination of ground water by nitrates. [13] stated that maize leaf nutrients concentrations were reduced with increasing applied water quantity, indicating that leaf N concentration with the 0.80 ET c treatment were generally equal to or higher than the concentrations with 1.00 ET c .…”

Variability in Optimum Nitrogen Rates for Maize

“…All primary sources of data, years, range in observed yields, and the predicted optimum N rate for all locations are reported in Table 1. Substantive published research has shown dramatic changes in optimum N rates varying from year to year at the same location (Al- Kaisi and Yin, 2003;Bundy et al, 2011;Eck, 1984;Fenster et al, 1978;Gehl et al, 2005;Ismail et al, 1994;Jokela and Randall, 1989;Mallarino and Ortiz-Torres, 2006;Meisinger et al, 1985;Olson et al, 1986;Peterson and Varvel, 1989;Randall et al, 2003;Rice et al, 1986;Shapiro and Wortmann, 2006;Stecker et al, 1993;Varvel et al, 2007;Vetsch and Randall, 2004;Woodruff et al, 1984). Nonetheless, given the importance of N for both crop production and the environment, no single document addresses the comprehensive nature of the problem or provides realistic and accurate estimates of the present variability in N rate recommendations.…”