Title of Oral/Poster Presentation

Nitrogen availability and use efficiency in corn treated with contrasting nitrogen sources.

Class

Article

Graduation Year

2017

College

College of Agriculture and Applied Sciences

Department

Plants, Soils, and Climate Department

Faculty Mentor

Jeanette Norton

Presentation Type

Poster Presentation

Abstract

Nitrogen (N) is required in relatively large quantities for corn production and is often the limiting nutrient for growth and high yield. Improved understanding of N cycling in agroecosystems is essential for increasing N use efficiency (NUE) and sustainable food production. The transformations between organic N and inorganic N form a central part of the internal soil N cycle. Utah farmers grow approximately 990, 000 tons of silage corn annually, which provides important forage in livestock and dairy diets. Properly harvested and stored silage corn is extremely palatable, superior to other forages in quality, energy content and a great fiber source. Our objectives were to evaluate N uptake by silage corn from the contrasting N sources and then calculate NUE over several years (2012-2016).

Field plots were established in 2011 at the Utah Experiment Station Greenville farm located in North Logan, Utah. The soil is an irrigated, very strongly calcareous Millville silt loam (Coarse-silty, carbonatic, mesic Typic Haploxeroll). The experimental design is a randomized complete block with four blocks and four nitrogen treatments: control (no N fertilization), ammonium sulfate (AS 112 and 224 kg N ha-1), and steer-waste compost (224 kg total N ha-1) for a total of 16 plots. Composted steer manure (obtained from Miller Co. Hyrum, UT) was analyzed for moisture and N content immediately before application to determine the mass needed to supply the 224 kg total N ha-1 rate. Treatments were surface applied in May of each year (2011 - 2016), incorporated by tilling immediately after application, and silage corn was planted within one week after treatment application as previously described (Yang et al 2016).

The corn brand DKC35-18 was used for planting. The corn leaf samples at 80 days were analyzed for total N. Corn was harvested, weighed and dried at 600 C in the oven drying rooms for yield determination. The dried samples were analyzed for total N using the Primacs N Auto Analyzer. NUE was calculated from the samples collected over 5 years (2012-2016). Difference method was used to determine NUE for all the samples by dividing the difference of total N uptake from N fertilized plots and unfertilized plots by the rate of fertilizer N applied. Soil organic C and total N were determined by dry combustion (PrimacsSLC for organic carbon, Primacs SN for total N, (Skalar, Inc, GA, USA). Soil inorganic N (ammonium and nitrate) were determined in May and August each year.

Data was analyzed based on the randomized complete block design with SAS system for Windows (SAS Institute, Cary, NC). All data was subjected to analysis of variance with significantly different means separated by Tukey’s (HSD) test. Multiple time series data was subjected to repeated measures analysis of variance with time as repeated measures factor. All statistical analyses were carried out at 95% confidence level (P< 0.05).

Dry matter yields and nitrogen uptake were dependent on treatment with ammonium sulfate fertilizers higher than compost and control and there was a significant treatment and year interaction. NUE showed a treatment effect and a treatment and year interaction that may be explained by differences in N uptake with water availability and seasonal inorganic N pools. The AS treatment overall had a NUE of approximately 60%. Although compost had lower NUE overall, the N was not lost from the system but accumulated in soil organic N. Nitrogen mineralization (release from organic N) is currently being examined in long-term incubations and by N-15 pool dilution experiments.

Acknowledgement: This work was supported by a grant from Agriculture and Food Research Initiative Competitive Grants Program Grant no. 2011-67019-30178 from the USDA National Institute of Food and Agriculture and by the Utah Agricultural Experiment Station project UTAO 1217.

Ouyang Y, Norton JM, Stark JM, Reeve JR, Habteselassie MY. (2016). Ammonia-oxidizing bacteria are more responsive than archaea to nitrogen source in an agricultural soil. Soil Biol Biochem 96: 4-15.

Location

North Atrium

Start Date

4-13-2017 10:30 AM

End Date

4-13-2017 11:45 AM

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Apr 13th, 10:30 AM Apr 13th, 11:45 AM

Nitrogen availability and use efficiency in corn treated with contrasting nitrogen sources.

North Atrium

Nitrogen (N) is required in relatively large quantities for corn production and is often the limiting nutrient for growth and high yield. Improved understanding of N cycling in agroecosystems is essential for increasing N use efficiency (NUE) and sustainable food production. The transformations between organic N and inorganic N form a central part of the internal soil N cycle. Utah farmers grow approximately 990, 000 tons of silage corn annually, which provides important forage in livestock and dairy diets. Properly harvested and stored silage corn is extremely palatable, superior to other forages in quality, energy content and a great fiber source. Our objectives were to evaluate N uptake by silage corn from the contrasting N sources and then calculate NUE over several years (2012-2016).

Field plots were established in 2011 at the Utah Experiment Station Greenville farm located in North Logan, Utah. The soil is an irrigated, very strongly calcareous Millville silt loam (Coarse-silty, carbonatic, mesic Typic Haploxeroll). The experimental design is a randomized complete block with four blocks and four nitrogen treatments: control (no N fertilization), ammonium sulfate (AS 112 and 224 kg N ha-1), and steer-waste compost (224 kg total N ha-1) for a total of 16 plots. Composted steer manure (obtained from Miller Co. Hyrum, UT) was analyzed for moisture and N content immediately before application to determine the mass needed to supply the 224 kg total N ha-1 rate. Treatments were surface applied in May of each year (2011 - 2016), incorporated by tilling immediately after application, and silage corn was planted within one week after treatment application as previously described (Yang et al 2016).

The corn brand DKC35-18 was used for planting. The corn leaf samples at 80 days were analyzed for total N. Corn was harvested, weighed and dried at 600 C in the oven drying rooms for yield determination. The dried samples were analyzed for total N using the Primacs N Auto Analyzer. NUE was calculated from the samples collected over 5 years (2012-2016). Difference method was used to determine NUE for all the samples by dividing the difference of total N uptake from N fertilized plots and unfertilized plots by the rate of fertilizer N applied. Soil organic C and total N were determined by dry combustion (PrimacsSLC for organic carbon, Primacs SN for total N, (Skalar, Inc, GA, USA). Soil inorganic N (ammonium and nitrate) were determined in May and August each year.

Data was analyzed based on the randomized complete block design with SAS system for Windows (SAS Institute, Cary, NC). All data was subjected to analysis of variance with significantly different means separated by Tukey’s (HSD) test. Multiple time series data was subjected to repeated measures analysis of variance with time as repeated measures factor. All statistical analyses were carried out at 95% confidence level (P< 0.05).

Dry matter yields and nitrogen uptake were dependent on treatment with ammonium sulfate fertilizers higher than compost and control and there was a significant treatment and year interaction. NUE showed a treatment effect and a treatment and year interaction that may be explained by differences in N uptake with water availability and seasonal inorganic N pools. The AS treatment overall had a NUE of approximately 60%. Although compost had lower NUE overall, the N was not lost from the system but accumulated in soil organic N. Nitrogen mineralization (release from organic N) is currently being examined in long-term incubations and by N-15 pool dilution experiments.

Acknowledgement: This work was supported by a grant from Agriculture and Food Research Initiative Competitive Grants Program Grant no. 2011-67019-30178 from the USDA National Institute of Food and Agriculture and by the Utah Agricultural Experiment Station project UTAO 1217.

Ouyang Y, Norton JM, Stark JM, Reeve JR, Habteselassie MY. (2016). Ammonia-oxidizing bacteria are more responsive than archaea to nitrogen source in an agricultural soil. Soil Biol Biochem 96: 4-15.