Thesis (Ph. D.)--Ohio State University, 1982. / Includes bibliographical references (leaves 117-120). Available online via OhioLINK's ETD Center

Doctor of Philosophy / Department of Agronomy / Scott A. Staggenborg and Alan J. Schlegel / Previous work in the High Plains with alternative planting geometries of corn and grain sorghum has shown potential benefits in dryland production. Studies conducted in 2009-2011 at Tribune, KS evaluated five planting geometries in corn and grain sorghum: conventional, clump, cluster, plant-one skip-one (P1S1), and plant-two skip-two (P2S2). Geometries were evaluated at three plant densities in corn: 3.0, 4.0, and 5.1 plants m[superscript]-2. Every measured corn production characteristic was affected by planting geometry, seeding rate, or an interaction in at least one of the years. Corn planted in a P2S2 configuration produced the least above-ground biomass, kernels plant[superscript]-1, kernels ear row[superscript]-1, and the highest kernel weight. Conventionally planted corn minimized harvest index and maximized stover production. Alternative geometries produced similar harvest indices. Grain yield response to seeding rate varied by geometry and year. Responsiveness and contribution of yield components were affected by geometry. Yield and yield components, other than ears plant[superscript]-1, were the least responsive to seeding rate in a cluster geometry. Clump planting consistently maximized kernels plant[superscript]-1. Prolificacy was observed in the cluster treatment and barrenness in the skip-row treatments. Light interception at silking was highest for clump and conventional geometries and lowest for the skip-row treatments. Corn in a P2S2 configuration did not fully extract available soil water. Conventionally planted corn had the lowest levels of soil water at tassel-silk indicating early-season use which potentially affected kernel set. In the lowest yielding year, grain water use efficiency was highest for clump and P2S2. Across-years, grain yields were lower for corn planted in a P2S2 geometry. Across-years corn yields were maximized when planted in clump at low or intermediate plant density, conventional and P1S1 at low plant density, P1S1 at high density, or cluster at any density. Planting grain sorghum in a P1S1 or P2S2 configuration reduced total biomass, grain yield, water use efficiency for grain production (WUEg), and water use efficiency for biomass production (WUEb) compared to conventional, clump, or cluster geometries at the yield levels observed in this study. Total water use was unaffected by planting geometry although cumulative water use at flower / grain fill was higher for conventional, clump, and cluster than for skip-row configurations. Sorghum planted in a conventional geometry was always in the highest grouping of grain yields. Grain yields from sorghum in either a cluster or clump geometry were each in the top yield grouping two of three years. When evaluated across-years, sorghum planted in a clump, cluster, or conventional geometry resulted in similar levels of above-ground biomass, grain yield, WUEg, and WUEb. Clump or cluster planting appear to have substantially less downside in a high yielding year than skip-row configurations. A comparison of corn and sorghum reinforced the findings of others that the relative profitability of the crops is largely dependent on the environment for any given crop year. Relative differences in grain yield, WUEg, WUEb, and net returns varied by year. Net returns over the three year study were maximized by conventional, cluster, and clump planted sorghum as well as clump planted corn.

Reduction in sulfur deposition from power plant emissions has resulted in lower amounts of soil sulfur and, perhaps, in inadequate sulfur availability for corn. The objective of this study was to determine if corn (<i>Zea mays</i> L.) grain yield was responsive to S fertilization in Indiana and what soil and cropping system factors contributed to the likelihood of a response. Field scale experiments were conducted at 28 sites from 2017 to 2020, the majority in corn-soybean (<i>Glycine max</i> (L.) Merr) rotation. In-season measurements included soil sulfate-S concentration and soil texture from 0 to 60 cm in 20 cm increments, plant nutrient concentration in the whole plant at V3-V7, in the earleaf, and in the grain. Additional measurements were 1,000 kernel dry weight, total kernel rows per ear, and kernels per row. Sulfur treatment rates ranged from 0 to 34 kg S ha^‑1 as ammonium thiosulfate, and were applied as starter, sidedress, and both combined. Fertilizer S increased grain yield by 0.2 to 3.0 Mg ha^-1 at 10 of 28 Indiana site-years, approximately a 36% frequency of response. When a response to S fertilizer occurred, the lowest sidedress rate examined in that site-year, which ranged from 8 to 17 kg S ha^-1,was enough to maximize grain yield. On soils with 26 to 31 g kg^-1 OM, S fertilization increased yield 0.2 to 0.3 Mg ha^-1 at 2 of 10 site-years. Response to S fertilization at 8 of 10 site-years with soils with lower OM, 10 to 25 g kg^-1, had higher yield increases ranging from 0.7 to 3.0 Mg ha^-1. Grain yield responses occurred in both coarse- and fine-textured soils and were consistent and large at 2 sites. Sulfate-S concentration in the soil and S concentration in the whole plant (V4-V7) were not good indicators of response to S fertilization. For the majority of the site-years where grain yield increased with S fertilization, the grain S concentration, earleaf S concentration, and earleaf N:S were respectively <0.9 g kg^-1, <1.8 g kg^-1, and >15:1 without S treatment. These parameters improved with the addition of S but some site-years with these values did not have a yield response. These earleaf S and N:S ‘critical values’ may serve as reference for potentially S responsive sites, but more observations are necessary to validate these critical levels. Sites with higher basal values (without fertilizer treatment) for earleaf and grain S concentration and lower earleaf N:S still showed increased tissue S concentration upon S fertilizer application, albeit with no increase in grain yield. We encourage farmers to consider S fertilization at rates ranging from 8 to 17 kg S ha^-1 applied at sidedress. this recommendation for fields showing S deficiency symptoms or where R1 earleaf S concentration and N:S are below 1.8 g kg^-1 and above 15:1, respectively.

Os contaminantes inorgânicos, entre eles o cádmio (Cd), estão associados a efeitos negativos na saúde humana e animal. Este projeto, em parceria com o Ministério da Agricultura, Pecuária e Abastecimento, foi desenvolvido com o objetivo de validar método analítico para determinação de Cd em matriz de alface para extensão de aplicabilidade em outras matrizes vegetais. A otimização e validação foram realizadas no Lanagro-SP em Campinas, sendo testadas as técnicas de digestão via seca, digestão via úmida em forno micro-ondas e suspensão ácida. A suspensão ácida propiciou melhores recuperações (70 a 110%), maior simplicidade de preparo e economia de reagentes, logo foi a técnica selecionada para validação. O método consiste em pesagem de 0,5 g de alface moído, adição de 2,5 mL de ácido nítrico, sonicação durante 20 minutos, tempo de reação de 2 horas e 20 minutos de centrifugação. As análises estatísticas consistiram em cálculo da média aritmética e coeficiente de variação entre replicatas de amostras. Para validação do método foram avaliados os seguintes parâmetros: sensibilidade, linearidade, precisão e exatidão com material de referência certificado, recuperação, seletividade ou efeito matriz, limite de detecção e quantificação, repetitividade e reprodutibilidade. Todos os experimentos da validação realizados até o momento estão de acordo com o requerido pelo Regulamento (CE) 657/2002 e INMETRO. As análises estatísticas consistiram basicamente em avaliação da média aritmética, desvio-padrão e coeficiente de variação. Após validação, o método foi utilizado para estudo de caso com amostras provenientes de experimento conduzido na USP/ESALQ Piracicaba com 63 bovinos de corte desmamados ½ Nelore x ½ Canchim em B. brizantha sob lotação rotacionada, com terminação em confinamento. O delineamento foi em blocos completos casualizados com três tratamentos e três repetições: T1 sal mineral ad libitum; T2 sal mineral + milho (0,3% do peso vivo PV); T3 sal mineral + milho (0,6% até 0,9% PV). Foram amostrados pasto, feno (Tifton 85), milho, sorgo, farelo de soja, solo, água, rins e fígado. As amostras vegetais foram preparadas pela técnica de suspensão ácida e os tecidos por calcinação, todos analisados por espectrometria de absorção atômica com forno de grafite (GF AAS). Na triagem algumas amostras estiveram abaixo do limite de quantificação (LQ) dentre elas a pastagem (13 µg kg-1), farelo de soja e milho (8 µg kg-1) e água (0,0025 mg L-1), ao passo que feno e sorgo permaneceram acima do L.Q. porém abaixo do limite máximo permitido (200 µg kg-1). O solo com pH ácido de 5,4 com 1,5 mg kg-1 de Cd. As amostras de fígado apresentaram teor abaixo do LQ (22 µg kg-1) e as de rim abaixo do máximo permitido (1000 µg kg-1). Não houve diferença entre tratamentos. Utilizou-se estatística descritiva para amostras vegetais e transformação logarítmica (10) nos dados de rim pelo SAS com médias comparadas pelo teste t a 5%. Não foram encontrados teores prejudiciais de Cd neste estudo. / The inorganic contaminants like cadmium (Cd) are toxic to human and animal health. This work, accomplished with Ministry of Agriculture, Livestock and Food Supply, had the purpose to validate an analytical method for Cd determination in lettuce samples and other vegetables samples. The development and validating steps were made on Lanagro-SP in Campinas. The techniques tested were dry ashing, microwave digestion and slurry. The slurry method had best recoveries (70 % up to 110%), the simplest preparing with less reagents, so it was selected to be validate. After optimizing the experimental parameters, the steps of the method were the following: weighting 0.5 g of ground lettuce; addition of 2.5 mL of HNO3 distilled; 20 minutes of sonication; 2 hours of standing and 20 minutes of centrifugation after volume completed for 25 mL. The statistical analyses were did evaluating means and relative standard deviation of the experiments. To validate the method the sensibility, linearity, precision and accuracy with certified reference material, recovery, matrix effects, limit of detection, limit of quantification, repeatability and reproducibility. All the experiments that have been done until now are in accordance with Comission Decision (CD) 2002/657/EC and INMETRO. The statistical analyses were basic the same at the development period. After the validation, the method was used in a screening with samples from ESALQ/USP Piracicaba experiment using 63 ½ Nelore x ½ Canchim beef steers, under a rotational grazing system in B. brizantha, finishing animals in feedlot. The experimental design was a randomized block with three treatments and three replications: T1 - mineral supplementation (MS) ad libitum; T2 - MS + corn (0.3% body weight BW); T3 - MS + corn (0.6% up to 0.9% BW). Samples of pasture, hay (Tifton 85), corn, sorghum, soybean meal, soil, water, kidney and liver were collected. Vegetables samples were prepared by acid slurry and animal tissues by dry ashing, and then all analyzed by graphite furnace atomic absorption spectrometry (GF AAS). Some samples were under limit of quantification (LOQ) like pasture (13 µg kg-1), soybean meal and corn (8 µg kg-1) and water (0.0025 mg L-1), while hay and sorghum were bellow acceptable levels (200 µg kg-1). Soil pH was 5.4 with a Cd content of 1.5 mg kg-1. The liver samples were under LOQ (22 µg kg-1) and kidney samples were bellow acceptable levels (1000 µg kg-1, FB).There was no difference between treatments. The vegetables data were submitted to descriptive statistics, while kidney means were transformed by log (10) on SAS and compared by t test in 5% level. No hazardous Cd concentrations were observed in this trial.

Thesis (M.S.)--Mississippi State University. Department of Agricultural Economics. / Title from title screen. Includes bibliographical references.

Made available in DSpace on 2016-08-12T19:18:27Z (GMT). No. of bitstreams: 1 LeonardoBT_TESE.pdf: 645262 bytes, checksum: cb8927bd356a80ce69fa745400bf047e (MD5) Previous issue date: 2014-04-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this work was to verify the effects of the combination between weeds and intercropping with gliricídia (thirty viable seeds m-2 broadcast) on the weed and corn yields. Completely randomized blocks design with four repetitions in subdivided parts was used. Hybrids (AG 1051 e BR 205) were cultivated in the parcels, and in the subportions the following treatments were applied: two weeds (twenty and forty days after corn sowing); a weed accomplishing 20 days after corn sowing + gliricídia sowing after weed; gliricídia sowing on the occasion of the corn sowing + weed accomplishing forty days after corn sowing; gliricídia sowing on the occasion of corn sowing; without weed. There was among hybrids with respect to baby corn, green spike and grains. The greatest yields were obtained through the treatment with two weeds, but the execution of a weed 20 days after corn sowing + gliricídia sowing after weed did not differ with respect to the yield of these three products according the weeds. Gliricídia sowing on the occasion of the sowing corn + weed after did not differ from the weeds with respect to the green spikes yield. Gliricídia sowing on the occasion of the corn sowing allowed averages superior to the treatment without weed and in some growth character and corn yield. Therefore, gliricídia controlled weed partially and its combination with weed has benefits / O objetivo do trabalho foi verificar os efeitos da combinação de capinas e consorciação com a gliricídia (30 sementes viáveis m-2 semeadas a lanço) no controle de plantas daninhas e nos rendimentos do milho. Utilizou-se o delineamento de blocos completos casualizados com quatro repetições em parcelas subdivididas. Os híbridos (AG 1051 e BR 205) foram cultivados nas parcelas, e nas subparcelas foram aplicados os tratamentos: duas capinas (20 e 40 dias após a semeadura do milho, DASM); realização de uma capina aos 20 DASM + semeadura da gliricídia após a capina; semeadura da gliricídia por ocasião da semeadura do milho + realização de capina aos 40 DASM; semeadura da gliricídia por ocasião da semeadura do milho; sem capinas.Não houve diferenças entre híbridos quanto aos rendimentos de minimilho, espigas verdes e grãos.Os maiores rendimentos foram obtidos com o tratamento de duas capinas, mas a realização de uma capina aos 20 DASM + semeadura da gliricídia após a capina, não diferiu das duas capinas quanto aos rendimentos desses três produtos. A semeadura da gliricídia por ocasião da semeadura do milho + realização de capina aos 40 DASM não diferiu das duas capinas quanto ao rendimento de espigas verdes. A semeadura da gliricídia por ocasião da semeadura do milho propiciou médias superiores ao tratamento sem capina em algumas características do crescimento e dos rendimentos do milho. Portanto, a gliricídia controla parcialmente as plantas daninhas e a combinação dela com capinas apresenta vantagens

Os contaminantes inorgânicos, entre eles o cádmio (Cd), estão associados a efeitos negativos na saúde humana e animal. Este projeto, em parceria com o Ministério da Agricultura, Pecuária e Abastecimento, foi desenvolvido com o objetivo de validar método analítico para determinação de Cd em matriz de alface para extensão de aplicabilidade em outras matrizes vegetais. A otimização e validação foram realizadas no Lanagro-SP em Campinas, sendo testadas as técnicas de digestão via seca, digestão via úmida em forno micro-ondas e suspensão ácida. A suspensão ácida propiciou melhores recuperações (70 a 110%), maior simplicidade de preparo e economia de reagentes, logo foi a técnica selecionada para validação. O método consiste em pesagem de 0,5 g de alface moído, adição de 2,5 mL de ácido nítrico, sonicação durante 20 minutos, tempo de reação de 2 horas e 20 minutos de centrifugação. As análises estatísticas consistiram em cálculo da média aritmética e coeficiente de variação entre replicatas de amostras. Para validação do método foram avaliados os seguintes parâmetros: sensibilidade, linearidade, precisão e exatidão com material de referência certificado, recuperação, seletividade ou efeito matriz, limite de detecção e quantificação, repetitividade e reprodutibilidade. Todos os experimentos da validação realizados até o momento estão de acordo com o requerido pelo Regulamento (CE) 657/2002 e INMETRO. As análises estatísticas consistiram basicamente em avaliação da média aritmética, desvio-padrão e coeficiente de variação. Após validação, o método foi utilizado para estudo de caso com amostras provenientes de experimento conduzido na USP/ESALQ Piracicaba com 63 bovinos de corte desmamados ½ Nelore x ½ Canchim em B. brizantha sob lotação rotacionada, com terminação em confinamento. O delineamento foi em blocos completos casualizados com três tratamentos e três repetições: T1 sal mineral ad libitum; T2 sal mineral + milho (0,3% do peso vivo PV); T3 sal mineral + milho (0,6% até 0,9% PV). Foram amostrados pasto, feno (Tifton 85), milho, sorgo, farelo de soja, solo, água, rins e fígado. As amostras vegetais foram preparadas pela técnica de suspensão ácida e os tecidos por calcinação, todos analisados por espectrometria de absorção atômica com forno de grafite (GF AAS). Na triagem algumas amostras estiveram abaixo do limite de quantificação (LQ) dentre elas a pastagem (13 µg kg-1), farelo de soja e milho (8 µg kg-1) e água (0,0025 mg L-1), ao passo que feno e sorgo permaneceram acima do L.Q. porém abaixo do limite máximo permitido (200 µg kg-1). O solo com pH ácido de 5,4 com 1,5 mg kg-1 de Cd. As amostras de fígado apresentaram teor abaixo do LQ (22 µg kg-1) e as de rim abaixo do máximo permitido (1000 µg kg-1). Não houve diferença entre tratamentos. Utilizou-se estatística descritiva para amostras vegetais e transformação logarítmica (10) nos dados de rim pelo SAS com médias comparadas pelo teste t a 5%. Não foram encontrados teores prejudiciais de Cd neste estudo. / The inorganic contaminants like cadmium (Cd) are toxic to human and animal health. This work, accomplished with Ministry of Agriculture, Livestock and Food Supply, had the purpose to validate an analytical method for Cd determination in lettuce samples and other vegetables samples. The development and validating steps were made on Lanagro-SP in Campinas. The techniques tested were dry ashing, microwave digestion and slurry. The slurry method had best recoveries (70 % up to 110%), the simplest preparing with less reagents, so it was selected to be validate. After optimizing the experimental parameters, the steps of the method were the following: weighting 0.5 g of ground lettuce; addition of 2.5 mL of HNO3 distilled; 20 minutes of sonication; 2 hours of standing and 20 minutes of centrifugation after volume completed for 25 mL. The statistical analyses were did evaluating means and relative standard deviation of the experiments. To validate the method the sensibility, linearity, precision and accuracy with certified reference material, recovery, matrix effects, limit of detection, limit of quantification, repeatability and reproducibility. All the experiments that have been done until now are in accordance with Comission Decision (CD) 2002/657/EC and INMETRO. The statistical analyses were basic the same at the development period. After the validation, the method was used in a screening with samples from ESALQ/USP Piracicaba experiment using 63 ½ Nelore x ½ Canchim beef steers, under a rotational grazing system in B. brizantha, finishing animals in feedlot. The experimental design was a randomized block with three treatments and three replications: T1 - mineral supplementation (MS) ad libitum; T2 - MS + corn (0.3% body weight BW); T3 - MS + corn (0.6% up to 0.9% BW). Samples of pasture, hay (Tifton 85), corn, sorghum, soybean meal, soil, water, kidney and liver were collected. Vegetables samples were prepared by acid slurry and animal tissues by dry ashing, and then all analyzed by graphite furnace atomic absorption spectrometry (GF AAS). Some samples were under limit of quantification (LOQ) like pasture (13 µg kg-1), soybean meal and corn (8 µg kg-1) and water (0.0025 mg L-1), while hay and sorghum were bellow acceptable levels (200 µg kg-1). Soil pH was 5.4 with a Cd content of 1.5 mg kg-1. The liver samples were under LOQ (22 µg kg-1) and kidney samples were bellow acceptable levels (1000 µg kg-1, FB).There was no difference between treatments. The vegetables data were submitted to descriptive statistics, while kidney means were transformed by log (10) on SAS and compared by t test in 5% level. No hazardous Cd concentrations were observed in this trial.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Performance of beef heifers grazing ryegrass (Lolium multiflorum Lam.) was studied exclusively with animals grazing, receiving grain corn, or whole oat grain at the level of 0.93% of body weight. The supplement was offered daily at 14 hours. The grazing was continuous with a variable number of animals. The experimental design was completely randomized with repeated measures, three feeding systems and nine replicates, each animal being considered an experimental unit. Supplementation with or without use of corn or oat grazing ryegrass reproductive development allows for the heifers are bred at 14 months of age. / Foi estudado o desempenho de novilhas de corte em pastagem de azevém (Lolium multiflorum Lam.), com animais exclusivamente em pastejo ou recebendo grão de milho inteiro ou grão de aveia branca em nível de 0,93% do peso corporal. O suplemento foi ofertado de segunda-feira à sábado às 14 horas. O método de pastejo foi contínuo com número variável de animais. O delineamento experimental foi o inteiramente casualizado, com medidas repetidas no tempo, três sistemas alimentares e nove repetições, sendo cada animal considerado uma unidade experimental. A utilização da pastagem de azevém, com ou sem uso de grão de milho ou aveia como suplemento, possibilita desenvolvimento reprodutivo para que as novilhas sejam acasaladas aos 14 meses de idade.

No description available.

The objective was to study the ingestive behavior, forage intake and pasture characteristics when beef heifers are kept exclusively in ryegrass pasture (Lolium multiflorum Lam.) or receiving cracked corn grain as a supplement (0.9% of body weight (BW )) with or without addition of crude glycerin (0.2% CP). Experimental animals were Angus heifers with initial age and body weight of eight months and 166.2 ± 9.5 kg, respectively. The grazing method was continuous with variable number of animals. The experimental design was completely randomized with repeated measures. The grazing method was continuous with variable number of animals. The experimental design was completely randomized with repeated measures. Heifers that received crude glycerin as supplement had longer trough time (min.) than heifers that received only cracked corn grain. The dry matter intake was estimated using chromium oxide technique as an indicator of fecal output. Heifers ingested similar amount of dry matter and neutral detergent fiber. The forage intake was 19.0% higher when the heifers remained exclusively in ryegrass pasture. The reduction in dry matter intake of forage by heifers receiving supplement provided increase of 38.2% in the stocking rate. / Objetivou-se estudar o comportamento ingestivo, ingestão de forragem e características da pastagem quando bezerras de corte são mantidas exclusivamente em pastagem de azevém (Lolium multiflorum Lam.) ou recebendo grão de milho quebrado como suplemento (0,9% do peso corporal (PC)) com ou sem adição de glicerina bruta (0,2% PC). Os animais experimentais foram bezerras Angus com idade e peso iniciais de oito meses e 166,2±9,5 kg, respectivamente. O método de pastejo foi contínuo, com número variável de animais. O delineamento experimental foi inteiramente casualizado, com medidas repetidas no tempo. As bezerras que receberam glicerina bruta como suplemento apresentaram maior tempo de cocho (min.) que as bezerras que receberam apenas grão de milho quebrado. O consumo de matéria seca foi estimado por meio de técnica do óxido de cromo como indicador da produção fecal. As bezerras ingeriram semelhante quantidade de matéria seca e fibra em detergente neutro. O consumo de forragem foi 19,0% maior quando as bezerras permaneceram exclusivamente em pastejo de azevém. A redução na ingestão de matéria seca da forragem pelas bezerras que receberam suplemento proporcionou incremento de 38,2% na taxa de lotação.