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Title:Innovations in fertilizer use and agronomic management for greater productivity of corn and soybean
Author(s):Beyrer, Tryston August
Director of Research:Below, Frederick E
Doctoral Committee Chair(s):Below, Frederick E
Doctoral Committee Member(s):Brown, Howard M; Mulvaney, Richard L; Riechers, Dean E
Department / Program:Crop Sciences
Discipline:Crop Sciences
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):agronomic management, corn, soybean, productivity, omission plot, row spacing, narrow rows, synergy, phosphorus, potassium, MicroEssentialsSZ, MESZ, Aspire, nitrogen, plant population, seed treatment, foliar protection, fungicide, insecticide, relative maturity, standard management, intensive management, fertilizer placement, banded, broadcast, plant height, nutrient concentration, nutrient content, nutrient use efficiency, phosphorus use efficiency, uptake efficiency, recovery efficiency, yield efficiency, soil test, yield potential, yield components, seed number, seed weight, grain quality,
Abstract:Increasing corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] grain yields will require a comprehensive understanding of the agronomic and nutritional factors that influence corn and soybean yields; therefore, it is critical to understand the interactions of these factors evaluated as a whole in order to efficiently maximize yield and exploit the yield potential of modern corn hybrids and soybean varieties grown under increased levels of management. A steady increase in corn and soybean grain yields have resulted in greater nutrient demands from the soil and fertilizer, resulting in many soil’s nutrient reserves to be drawn down. With the advent of innovative precision agricultural technologies, fertilizer sources, and management practices, current evolving management practices need to be constantly reevaluated in order to capitalize on potential synergies that may be necessary to realize the genetic yield potential of corn and soybean. For these reasons, the objective of this research was to quantify how modern agronomic and fertilizer management practices can be employed for greater corn and soybean productivity that encompassed three research areas: Can agronomic management practices be combined to achieve synergistic improvements in corn and soybean productivity? Yield potential of a particular corn hybrid or soybean variety is greatest when the seed is still in the bag, but observed yield is always less. By using agronomically sound management practices yields may be increased (or potential yield loss minimized) from current production averages. The objective of this experiment was to evaluate potential synergies between several management practices when combined under Intensive management systems, or the consequences of not including or minimizing a particular factor and the impact that it contributes in both Standard and Intensive management systems. The major management factors that were evaluated included phosphorus (P) and potassium (K) fertility, foliar protection, sidedress nitrogen (corn only), plant population (corn only), relative maturity (soybean only), seed treatment (soybean only) and row spacing. Individual agronomic factors such as narrower row spacing or P and K fertilizer applications resulted in the largest yield increases of all management practices; however, combinations of multiple management factors in Intensive management systems resulted in synergistic yield increases of 23% for corn and 21% for soybean over that of Standard management systems. Synergies took place in both crops, suggesting that corn and soybean producers could potentially take advantage of greater yield increases and exploitation of seed genetic yield potential when using a combination of management factors. How accurate does a banded phosphorus (P) nutrient application need to be placed to the crop row, to result in equivalent or greater plant growth and grain yields than traditional broadcast applications? Increased vegetative plant growth and greater yields from banded phosphate-based MicroEssentials SZ than other agronomic factors found in the first study merits consideration of the possibility that other fertilizer application strategies can result in similar yield responses. Traditionally, most fertilizer applications are broadcast across the soil surface; however, modern corn hybrids and soybean varieties planted at increased populations result in smaller root systems that may not effectively exploit relatively immobile nutrients such as P, especially when placed between the crop rows. Banding fertilizer beneath the crop rows places nutrients in relatively close proximity to the crop roots, and may require modern precision guidance equipment for optimal placement. Research was conducted to determine how corn and soybean plants respond to P fertilizer placed at different distances away from the crop row (broadcast, or bands 0, 3, 6, 9, 12, 15 inches), and whether changes in plant population would influence the efficacy of fertilizer applications. High plant populations resulted in greater yields than low plant populations, but the greatest yields and nutrient uptake occurred with banded P fertilizer applications directly beneath the crop row, while fertilizer bands placed approximately six inches to the side of the crop row resulted in yields similar to that of broadcast fertilizer. These findings support the idea that precision fertilizer placement and high planting densities can influence many growth parameters and nutrient uptake in corn and soybean. Do soil test values accurately predict yield responses to banded P fertilizer, or what other assessments should be used? With greater emphasis on P soil test levels for nutrient stewardship strategies and the known potential detrimental effects from P-loss to water bodies, soil tests need to accurately predict critical levels so that yield responses from fertilizer are likely and profitable. There has been an advent of increased adoption of improved fertilizer technologies, such as precision guidance for application, banding fertilizer beneath the row, and new fertilizer formulations that provide season-long nutrient availability. The objective of this research was to determine if the existing soil test level recommendations for P are adequate predictors of the yield response to added P fertilizer. Employing multiple 4R nutrient stewardship practices, such as spring-banded MicroEssentials SZ in this particular study, resulted in significant increases in corn and soybean grain yields even when a majority of the soil test levels were considered to be sufficient. In general, P soil tests were one of the most consistent predictors of yield responses to P fertilizer despite their relatively low rate of predictability, and higher soil test level threshold for a probability of yield response, which could likely be improved upon based on current recommendations.
Issue Date:2018-04-18
Type:Thesis
URI:http://hdl.handle.net/2142/101177
Rights Information:Copyright 2018 Tryston Beyrer
Date Available in IDEALS:2018-09-04
Date Deposited:2018-05


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