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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Effects of Corn-Soybean Rotations on No-Till Corn Productivity

Wolfe, Alice Marie January 1993 (has links)
No description available.
132

Overseeding the cover crops Hairy Vetch (Vicea Villosa Roth) and Medium Red Clover (Trofolium Pratense L.) into corn (Zea Mays L.) after the last cultivation: effects on corn yield and cover crop production of dry matter and ground cover residue

Townsend, Marjorie Louise January 1998 (has links)
No description available.
133

A system for the classification of corn inbred lines

Butler, Daniel Robert January 1954 (has links)
No description available.
134

Studies of Some Factors Affecting the Establishment of Certain Forage Species.

Anderson, Gordon Colin January 1957 (has links)
No description available.
135

Exchange studies of p³² and p³¹ in plants

Yuan, Tzu-Liang January 1955 (has links)
No description available.
136

SOYBEAN YIELD AND QUALITY RESPONSE TO FLUID STARTER SULFUR FERTILIZER

Nicholas James Roysdon (11820809) 18 December 2021 (has links)
<p>Sulfur (S) demand has increased as atmospheric deposition of S decreased and soybean (<i>Glycine max</i> (L.) Merr.) production has increased. Soybean growers have invested into agronomic practices to maximize production and alleviate potential S shortfalls including the use of starter fertilizer. For this reason, this study was designed to quantify and qualify the effects of fluid starter S fertilizer on soybean yield. The objectives were to determine an optimum source, rate, and placement of fluid starter fertilizer. A split-plot design of S source-rate and placement was used in 2019 and 2020 at West Lafayette and Wanatah, Indiana. Three starter S fertilizers were used: ammonium thiosulfate (ATS, 12-0-0-26S, Hydrite Chemical), potassium thiosulfate (KTS, 0-0-25-17S, Hydrite Chemical), and K-Fuse (derived from potassium acetate, ammonium thiosulfate and urea 6-0-12-12S, NACHURS) as well as broadcast granular ammonium sulfate (AMS, 21-0-0-24S), and an untreated control. Starter S products were applied at four S rates: 5.6, 11.2, 16.8, and 22.4 kg S ha<sup>-1</sup> to determine optimal S rate and in two placements (single: 0x5x1-cm; dual: 0x5x2-cm). AMS was broadcast at 22.4 kg S ha<sup>-1</sup></p> <p>Placement did not affect a majority of the factors analyzed and was largely factored out when not significant. Leaf concentrations of essential macro-nutrients, including S, were above critical levels and were not affected by starter fertilizer at any site-year. ATS increased manganese (Mn) in 2019 and 2020 and Wanatah. In West Lafayette 2020 (timely planting), all three starter sulfur fertilizers increased yield and protein, while broadcast AMS did not. Yield and protein did not change with starter S fertilizer in the remaining site-years, which was likely due to plantings later than recommended.</p> <p>To evaluate and quantify the effects of fluid starter fertilizer across early and late planting dates, a split-plot design was used with an earlier (May 13, 2020) and late (June 8, 2020) planting dates at West Lafayette, IN, as well as early (P24A80X) and late (P35A33X) maturing soybean varieties at Wanatah, IN. These were crossed with six fertility treatments: ammonium thiosulfate (ATS, 12-0-0-26S), potassium thiosulfate (KTS, 0-0-25-17S), K-Fuse (6-0-12-12S, NACHURS), 28% urea ammonium nitrate (UAN, 28-0-0), ammonium sulfate (AMS, 21-0-0-24S), and an untreated control. Starter S fertilizers were applied at 16.8 kg S ha<sup>-1</sup> and 28% UAN was applied at a 7.9 kg Nitrogen (N) ha<sup>-1 </sup>rate, all in a single (0x5x1-cm) placement.</p> <p>The earlier planting had greater stand and yield than the later planting. Starter fertilizers did not impact yield, protein or oil compared to untreated control. Earlier-planted soybean with KTS had higher S concentration in the leaves than UTC and other fertility treatments. Variety impacted leaf nutrient and seed protein concentration. Leaf nutrient concentrations was generally higher in the 3.5 variety compared to the 2.4 variety. Protein was higher in the 2.4 variety compared to the 3.5 variety. However, yield was not affected by variety, fertilizer, or a variety x fertilizer interaction. There was also no fertilizer effect on any essential nutrient concentration. </p> <p>Soybean positive response to starter S fertilizer aligned with timely plantings rather than later plantings. Earlier plantings were cool and wet field conditions, which limited mineralization of soil organic matter and the supply of N and S. The highest yield was 4308 kg ha<sup>-1</sup> with KTS in West Lafayette 2020, applied at a rate of 7.5 kg S ha<sup>-1</sup>, followed by K-Fuse and ATS, respectively. Given the minimal response to different placements, it can be concluded that the difference between single and dual placements on soybean growth and yield is negligible.</p>
137

Edge-of-field Associated Nitrate-N Loss in a Soybean-corn Rotation

Mitchell J Greve (8108663) 12 December 2019 (has links)
<p>Across the United States corn-belt region substantial quantities of nitrogen (N) fertilizer are applied in both continuous corn (<i>Zea mays</i>L.) and corn grown in rotation with soybean [<i>Glycine max</i>(L.) Merr.]. When compared to continuous corn, corn grown in rotation with soybean typically receives less applied N fertilizer (typically 20-45 kg ha<sup>-1</sup>less) than continuous corn due to expected carryover of N from biological N fixation (BNF) by soybean in the preceding year. However, when current N recommendations are followed in both systems, rotational corn has been shown to lose similar or, in some cases, greater amounts of N through subsurface tile lines than continuous corn although the reports in the literature have been inconsistent. In rain-fed systems a key limitation to many previous studies has been an insufficient number of site-years of data to fully characterize management effects across varied environments. Regardless, the development of better management practices to reduce nitrate leaching losses has largely remained focused on managing N applied to corn and soybean’s role in degradation of surface water has been relatively understudied in tile drained agroecosystems. Therefore, the objectives of this study were to use a 23-yr data record to: (1) compare quantities and patterns of N loss in tile drainage water among a soybean-corn rotation fertilized with the recommended preplant N rate, a soybean-corn rotation fertilized with a N reduced rate applied as a sidedress, continuous corn fertilized with the recommended preplant N rate, and an unfertilized, restored prairie as a natural system control, (2) determine whether and when cumulative soybean-corn load losses in drainage water surpassed that of continuous corn, and (3) evaluate the current recommended N credits from the dual perspective of crop productivity and protection of water quality. </p><p> Established in 1992, the Purdue University Water Quality Field Station has continuously assessed field-scale N cycling and losses in tile drains and the N management of the five treatments examined in this study have been maintained since 1995. Treatments were 135 kg N ha<sup>-1 </sup>applied in rotational corn as a sidedress at approximately V6 each year (CS-135), 157 kg N ha<sup>-1</sup>applied preplant in rotational corn (CS-157), and 180 kg N ha<sup>-1</sup>applied preplant in continuous corn (CC-180). All corn plots received 23 kg N ha<sup>-1</sup>as starter at planting. A restored perennial prairie control with no fertilizer applied (Pgrass) was utilized to compare and discuss the implications of intensively fertilized annual row crops. The 23-yr data record includes N concentration in drainage water, drainflow volume, N load losses in drainflow, grain yield, tissue N concentrations at harvest and N amounts returned to soil in crop residues and removed in grain. </p> Analysis of variance found CS-157 resulted in significantly greater daily flow-proportional N concentrations (23-year mean 11.98 mg L<sup>-1</sup>) when compared to all other cropping systems (≤ 10.96 mg L<sup>-1</sup>). No reportable significant differences occurred in mean annual drainage flow volume among the respective cropping systems. Annual N load loss was statistically similar among cropping systems, ranging between 9.88 to 12.32 kg N ha<sup>-1</sup>yr<sup>-1</sup>, and these were all significantly higher than the Pgrass control (1.70 kg N ha<sup>-1</sup>yr<sup>-1</sup>). When corn and soybean years in rotational systems were analyzed separately for leaching losses, CS-157 was significantly higher than CS-135 and CC-180 (14.70, 10.85 and 11.88 kg N ha<sup>-1</sup>, respectively) whereas losses by SC-157 and SC-135 were similar averaging 12.26 and 12.13 kg N ha<sup>-1</sup>, respectively. Nitrogen treatment did not impact either corn or soybean mean yields. We concluded that soybean BNF production may be a major driver in N load loss in rotational corn when compared to continuous corn and further reductions in load losses from rotational systems will require a focus on managing soybean-derived N. Lastly, future research should include monthly or seasonal assessment of N load losses to better target practices at vulnerable times of nutrient loss.
138

The Yield and Thiamine, Riboflavin, and Niacin Content of Alfalfa Hay as Related to Fertilizer Treatment of Soil

Pathak, Rasik L. 01 May 1951 (has links)
Alfalfa has long been recognised as an outstanding hay plant in terms of both yield and feeding value. It is high in digestible proteins minerals, and vitamins. Because of its long life. it can be economlcally produced. It is of exceptlonal value in maintalning soil fertility by helping to control erosion, by improving the physical condition of the soil, and by accumulating large amounts of nitrogen.
139

Evaluation of Water-Deficit Responses in Wild-By-Cultivated Rice Introgression Lines

Rachel Katrina Imel (13912470) 10 October 2022 (has links)
<p>  </p> <p>Rice (<em>Oryza sativa</em> L.) is a staple crop consumed globally. Increased variability in rainfall in much of the world is a predicted consequence of climate change and drought is predicted to be a major cause for concern for rice production. One approach to mitigating water-deficit stress is integrating beneficial (drought-tolerance) loci from wild rice donors into elite rice cultivars. Bi-parental interspecific chromosome segment substitution lines (CSSLs) and near introgression lines (NILs) are genetic resources that contain genetic introgressions from wild rice but are otherwise genetically identical to the cultivated parent, known as the recurrent parent. For this study, 12 CSSLs and NILs were selected for having wild rice introgressions on chromosomes two and five, previously shown to be beneficial under field conditions. In the current work, these lines were evaluated under water-deficit conditions for their potential of serving as future pre-breeding material. The recurrent parents, Cybonnet and Jefferson, two U.S. cultivars adapted to the Southern Rice Belt, were additionally included in this study as controls. In total, three trials took place: two at Purdue University under controlled environments (West Lafayette, Indiana) and one in the field at the Dale Bumpers Rice Research Center (Stuttgart, Arkansas). Traits such as yield components, gas exchange, leaf water content, leaf water potential and chlorophyll fluorescence were measured during predawn and midday timepoints. Results from the three trials did not show consistent genotype rankings in yield component traits, which was expected due to the different ways in which water-deficit treatments were approached (continuous water-deficit application versus transient drought and recovery). While many of the CSSLs outranked Cybonnet in mean values, none were significantly different, likely due to low replication. Despite not having identified superior genotypes, the yield component, physiology, and high-throughput phenotyping datasets published here can provide the foundation to address future questions about physiological linkages and methodology development associating high-throughput data with ground-truth measurements. All data associated with this work are publicly available through Purdue University Research Repository.</p>
140

Factors associated with pea foot rot complex and methods of disease prediction

Bibble, Anthony John January 1993 (has links)
No description available.

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