Improved agronomic management of corn and soybean to increase productivity

Guenzburger, Dylan Reed

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https://hdl.handle.net/2142/112957 Copy

Description

Title

Improved agronomic management of corn and soybean to increase productivity

Author(s)

Guenzburger, Dylan Reed

Issue Date

2021-06-07

Director of Research (if dissertation) or Advisor (if thesis)

Below, Frederick

Committee Member(s)

• Brown, Howard
• Mulvaney, Richard

Department of Study

Crop Sciences

Discipline

Crop Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Agronomy
• corn
• soybean
• starter fertilizer
• nitrogen
• fertilizer placement

Abstract

Production of soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) has increased nearly five-fold and seven-fold, respectively, since the United States Department of Agriculture started recording grain yields for both crops. Despite these staggering increases, there is still potential to increase grain yield even further to help feed the world’s growing needs. Of course, none of this would have been possible without improved crop management and cultivars that have led to these ever-increasing yields. While growers do not have much influence in the genetics that come to market, it is up to them to implement whatever agronomic management practices they wish to use. A drawback to these increases in soybean and corn grain yields is that nutrient demands have increased as well. To combat higher nutrient demands, innovative fertilizer sources as well as advanced application technologies are being developed that could potentially help to drive the continual increase in yields. Hence, the objective of this research was to evaluate some fertilizer source and application technologies to help increase soybean and corn productivity. The three research projects conducted as part of this thesis include: Starter Fertilizer and Agronomic Management to Improve Growth and Productivity of Corn Advancements in nutrient placement technologies over the past several decades have given farmers the ability to better manage plant nutrition, especially phosphorus. One management method that has been widely adapted for corn is the placement of small quantities of mineral nutrients as liquids in the seed furrow at planting, known as ‘starter fertilizer’. This placement can be beneficial as the small root system of seedlings usually lacks ample mass or extent to acquire sufficient quantities of nutrients from the soil. Along with mineral nutrients, plant growth regulators and biostimulants can be included in these in-furrow solutions that can enhance early season growth and in some cases also increase grain yield. The objective of this study was to evaluate the ability of in-furrow starter fertilizer and starter fertilizer additives to increase growth and yield of corn grown with two different levels of agronomic management. The trial was conducted at Champaign, Illinois in 2019 and an untreated control was compared to in-furrow placement of 10-34-0 by itself or combined with six different fertilizer. These treatments were placed within either a standard or an intensive system of agronomic management. The standard management system received 180 lbs N acre-1 pre-plant with P and K fertilization based on soil test values, was at a plant density of 32,000 plants acre-1 in a 30-inch row spacing, and received no foliar fungicide. The intensive input system included 180 lbs N acre-1 at planting, along with 100 lbs P2O5, 30 lbs N, 25 lbs S, and 2.5 lbs Zn per acre banded directly under the crop row, and 75 lbs K2O and 0.6 lbs B per acre broadcast at planting. The intensive system was grown at a plant density of 44,000 plants acre-1 in a 20-inch row configuration with an additional 80 lbs N acre-1 side-dressed at V8, and a fungicide & insecticide application at the VT growth stage. The starter fertilizer additives were applied in-furrow at planting to both management systems and included two rates of both Ultra-Che Zinc 9% EDTA and Levesol Zinc, and the plant growth regulator formulations of Cygin and Cygin Enz. Corn plants grown in the intensive input system had 7 % greater overall growth at V6, and yielded an average of 43 bushels acre-1 more than plants grown under standard management. However, in the intensive input system, none of the in-furrow treatments further increased yield compared to the untreated control, but led mostly to numerically lower yields (range of 0 to 18 bushels acre-1 lower). Conversely, within the standard management system, starter fertilizer and starter fertilizer additives increased early season growth, and while not statistically significant, all in-furrow treatments increased yields by 4 to 11 bushels acre-1. Collectively, these findings show that the use of starter fertilizer and starter fertilizer additives interacts with the level of agronomic management to impact growth and productivity of corn. Nitrogen and Phosphorus Management Practices to Improve Corn Grain Yield Fertilizer nutrient applications to corn vary accordingly to the management practices being implemented by growers and the products being utilized. Nitrogen (N) and phosphorus (P) management have been especially scrutinized due to their potential for negative environmental impacts, and identifying better timing and/or placement strategies for these nutrients in corn production was the objective of this research. Timing strategies for N application included all N applied pre-plant compared to a 3-way split application of one-third broadcast prior to planting, one-third applied at planting in a 2x2 band, and one-third applied in-season using the Y-drop application method. In all cases, the total N application was 180 lbs N acre-1 as 32 % urea ammonium nitrate (UAN). Both the N timings were evaluated with four different placements of P utilizing ammonium polyphosphate (10-34-0) either as: none, 20 lbs P2O5 acre-1 in-furrow, 40 lbs P2O5 acre-1 2x2 band, or 60 lbs P2O5 acre-1 via 20 lbs acre -1 in-furrow plus 40 lbs acre-1 2x2 band. This study was conducted at three locations across Illinois in 2020. All three sites experienced excessive spring rainfall that delayed planting, and all sites were drier than normal during grain filling, leading to lower yields than typically observed at these sites. Early season growth and final grain yields at Yorkville and Champaign were not affected by either N application timing or by the methods of P placement, although N uptake was higher for plants receiving the 2x2 banded P placement at Champaign. These findings suggest that the higher natural soil fertility at these sites combined with the warmer soil temperatures due to later planting led to greater mineralization of N and P, and this masked the value of the N timing and 10-34-0 planting placement treatments. At Nashville, where the natural soil fertility is lower, early season growth as indicated by V8 NDVI value was significantly increased by most of the 10-34-0 planting placement treatments. This extra growth, however, did not translate into higher yields as all the 10-34-0 placement treatments decreased grain yield below the no-P controls, and these decreases were associated with fewer kernel numbers, lighter kernel weights, and less plant N accumulation. Collectively, the results from 2020 showed that split applications of N and planter-applied applications of P did not result in better N use or higher grain yields than applying all of the N pre-plant without any additional P, and demonstrated the difficulty in improving fertilizer use in corn production. Different Combinations of Fertilizer Sources to Increase Productivity of Soybean There is common perception among growers that soybean requires less fertilization and that soybean yields are beginning to plateau in comparison to corn. Recent studies, however, have illustrated how modern soybean varieties require nutrients in amounts similar to that of corn and are capable of higher yields through better agronomic management. The objective of the research was to evaluate fertilization of soybean using different combinations and sources of fertilizers. All the fertilizer sources were balanced for phosphorus (P) and potassium (K) and differed in the products being applied, in the amounts of nitrogen (N), sulfur (S), magnesium (Mg), and boron (B), that they contained, and whether they were co-granulated or mixtures of granulated sources. Soybean was sown at three varying regions in Illinois (northern, central, and southern). Although none of the fertilizer treatments statistically increased soybean yields over the untreated controls there were some clear and interesting trends. Despite the common perception that lower inherent fertility soil of southern Illinois would have the best response to fertilizer treatments, that was not the case. The best yield responses to fertilizer treatments were at the higher inherent fertility locations of Yorkville and Champaign. At Yorkville, yield were greatest using P and K fertility without S, as the soil test values for S were sufficient. Grain quality was only found to be consistently impacted by fertilizer treatments at Yorkville, where the treatments often significantly increased seed protein concentration. At Champaign, S fertilization helped yields, as P and K fertilization tended to decrease yields compared to the untreated control. At Champaign in 2019, supplying 10 lbs S acre-1 led to greater yields than supplying 20 lbs S acre-1, while S treatment results were mixed in 2020 probably because of a hailstorm at the onset of reproductive growth that caused 75 % leaf defoliation. At the southern Illinois sites of Ewing and Nashville, the yield responses to fertility were marginal, regardless of year or S supply. At none of the sites or years were there any clear yield trends from fertilizer sources that supplied N, Mg, or B. The results of this research showed that fertilization of soybean was most beneficial in regions that contained higher inherent soil fertility.

Graduation Semester

2021-08

Type of Resource

Thesis

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Copyright 2021 Dylan Guenzburger

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