Pressure and angle of the seed-fertilizer drill press wheel on corn emergence

ABSTRACT In precision seed-fertilizer drills, the soil compaction mechanism is responsible for closing the furrow, pressing the soil over the seed. Among the available models, the most used is the V-type wheel system, with several options to regulate the wheel opening angle and pressure exerted on the soil. This study was carried out in the experimental area of the Federal University of Fronteira Sul - Campus Cerro Largo, in an clayey Red Latosol. Parameters related to corn emergence and the seedbed characteristics were evaluated at different regulations of opening angle and pressure of the compaction mechanism. The results indicate that mechanism regulations had no influence on emergence speed, emergence speed index and population of corn plants, under the studied conditions. However, the treatment with highest load and parallel alignment of the wheels caused lower values of elevated area and swelling. Treatments with 15° opening angle caused accumulation of soil in the center of the row, affecting the elevation height.

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CORN DEVELOPMENT AND PRODUCTION IN FUNCTION OF SOURCES OF NITROGEN FERTILIZERS AND DOSES

Revista Caatinga ◽

10.1590/1983-21252016v29n405rc ◽

2016 ◽

Vol 29 (4) ◽

pp. 812-821

Author(s):

FERNANDO CASTRO OLIVEIRA ◽

MAURILIO DE SOUSA NETTO ◽

LUCAS DA SILVA ARAUJO ◽

ANDRÉ CIRILO DE SOUSA ALMEIDA ◽

PEDRO MARQUES DA SILVEIRA ◽

...

Keyword(s):

Block Design ◽

Nitrogen Fertilizers ◽

Grain Productivity ◽

Significant Difference ◽

Coated Urea ◽

Red Latosol ◽

High Doses ◽

Corn Plants ◽

Favorable Conditions ◽

The City

ABSTRACT Nitrogen (N) is one of the nutrients that have the most significant effect on corn grain productivity increase. In order to evaluate the effect of sources of N topdressing and doses in the grown corn culture, in a conventional till system, it was installed an experiment in the city of Urutaí, Goiás, in the 2012/13 crop, in clayey textured Red Latosol. The experimental design was a randomized complete block design with four replications, with the treatments arranged in a factorial 3 x 5, consisting of three sources (coated urea, urea and ammonium sulfate) and five doses (0, 60, 120, 180 and 240 kg ha-1) of N, topdressing, applied in the surface and in a single dose, when the corn plants were in V4 stage. The hybrid used was the P3646H. We evaluated the following characters: stem diameter, plant height, height of ear insertion, leaf N, number of ears per plant, ear length, number of rows per ear, number of grains per row, 100 grains mass and grain productivity. All characters have a response to nitrogen fertilization and only the height of ear insertion showed no significant difference between sources. The source coated urea showed the best results, indicating that its use may be compensatory, especially in favorable conditions for the NH3 volatilization, as the application of high doses of N in the surface.

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DESENVOLVIMENTO INICIAL DO MILHO EM RESPOSTA A DOSES DE POTÁSSIO

Revista Brasileira de Milho e Sorgo ◽

10.18512/1980-6477/rbms.v17n1p27-36 ◽

2018 ◽

Vol 17 (1) ◽

pp. 27

Author(s):

MATEUS DE PAULA GOMES ◽

JOÃO PEDRO DE BARROS REICAO CORDIDO ◽

MÁRCIO LUIZ DOS SANTOS ◽

ARIANA MOTA PEREIRA

Keyword(s):

Zea Mays ◽

Soil Compaction ◽

Dry Matter ◽

Maize Seedlings ◽

Initial Development ◽

Cation Uptake ◽

Maize Plants ◽

Red Latosol ◽

Mg Content

RESUMO - Objetivou-se avaliar o efeito de doses de potássio e níveis de compactação de solos no desenvolvimento inicial e na absorção de cátions em plantas de milho. Foram desenvolvidos dois experimentos utilizando amostras de um Latossolo Vermelho de textura média (LV) e de um Latossolo Vermelho-Amarelo de textura muito argilosa (LVA). Os ensaios foram conduzidos em blocos casualizados com arranjo fatorial 3×6, sendo três densidades de solo e seis doses de potássio, com três repetições. A compactação do solo não influenciou no acúmulo de matéria seca nem na absorção dos cátions pelas plantas de milho. O aumento das doses de K reduziu a absorção e o teor de Ca das plântulas de milho cultivadas no LVA e reduziu a absorção e teor de Mg das plântulas de milho cultivadas em ambos os solos. O aumento das doses de K favoreceu a absorção de Mn, Fe, Cu e Na em plântulas de milho cultivadas em LV. As doses de K não influenciaram na absorção de Ca e Zn em plântulas de milho cultivadas em LV, nem na absorção de Fe, Zn, Cu, Mn, Na em plântulas de milho cultivadas em LVA. Palavras-chave: inibição da absorção, Zea mays, absorção de cátions. INITIAL MAIZE DEVELOPMENT IN RESPONSE TO POTASSIUM DOSES ABSTRACT - The objective of this work was to evaluate the effect of potassium doses and levels of soil compaction on initial development and cation uptake in maize plants. Two experiments were carried out using samples of a Red Latosol (LV) and a Red-Yellow Latosol with very clayey texture (LVA). The trials were conducted in randomized blocks with factorial arrangement 3×6, being three soil densities and six potassium doses, with three replications. Soil compaction did not influence the accumulation of dry matter or cation uptake in maize plants. Increased K doses reduced the uptake and Ca content in maize plants grown in the LVA and reduced the uptake and Mg content in maize plants grown in both soils. Increased K doses favored the absorption of Mn, Fe, Cu and Na in maize seedlings when grown in LV. K doses did not influence the uptake of Ca and Zn in maize seedlings grown in LV, nor the absorption of Fe, Zn, Cu, Mn and Na in maize seedlings grown on LVA. Keywords: inhibition of absorption, Zea mays, cation absorption.

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Levels of induced pressure and compaction as caused by forest harvesting operations

CERNE ◽

10.1590/s0104-77602013000100011 ◽

2013 ◽

Vol 19 (1) ◽

pp. 83-91 ◽

Cited By ~ 3

Author(s):

Paula Cristina Caruana Martins ◽

Moacir de Souza Dias Junior ◽

Josemar da Silva Carvalho ◽

Arystides Resende Silva ◽

Sebastião Machado Fonseca

Keyword(s):

Uniaxial Compression ◽

Soil Compaction ◽

Soil Structure ◽

Forest Harvesting ◽

Soil Samples ◽

Uniaxial Compression Test ◽

Traffic Intensity ◽

Undisturbed Soil ◽

Before And After ◽

Red Latosol

This study aimed to determine levels of pressure and compaction induced by forest harvesting operations in a Red Latosol (LV) under planted eucalyptus. Undisturbed soil samples were collected from layers 0-3 and 15-18 cm and then used in a uniaxial compression test. Sampling was done before and after harvesting operations. Equipment being evaluated included: harvester, feller buncher, forwarder, self-loading adapted tractor, standard truck, wide-tire truck and grapple saw. Average pressures induced by the grapple saw were 320 kPa and 272 kPa, causing compaction in 80% and 20% of samples respectively from layers 0-3 cm and 15-18 cm, which indicates substantial degradation of soil structure in areas where timber is processed. In layer 0-3 cm, average pressures induced by the harvester and by the feller buncher were 240 kPa and 263 kPa respectively, while in layer 15-18 cm pressures were 234 kPa and 239 kPa respectively. The feller buncher caused higher soil compaction than the harvester in layer 0-3 cm, yet in layer 15-18 cm they had similar behavior. All timber forwarding equipment led to soil compaction. The wide-tire truck was the forwarding implement promoting the highest rate of compaction, in both residue conditions. Traffic intensity 7 promoted the highest rate of soil compaction.

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Previous cultivation of palisade grass and soil correctives: influence on growth and yield of soybean cultivated under various soil compaction levels

Ciência e Agrotecnologia ◽

10.1590/s1413-70542011000600013 ◽

2011 ◽

Vol 35 (6) ◽

pp. 1132-1140 ◽

Cited By ~ 1

Author(s):

Marcos André Silva Souza ◽

Douglas Ramos Guelfi Silva ◽

Fabrício William Ávila ◽

Valdemar Faquin ◽

Geraldo César de Oliveira ◽

...

Keyword(s):

Glycine Max ◽

Experimental Design ◽

Soil Compaction ◽

Calcium Silicate ◽

Growth And Yield ◽

Soil Density ◽

Glycine Max L ◽

Red Latosol ◽

Urochloa Brizantha ◽

Harmful Effects

Soil compaction directly interferes on crop yield. The objectives of this work were to evaluate the effect of previous cultivation with palisade grass [Urochloa brizantha (C. Hochstetter ex A. Rich.) R. Webster cv. Marandu] and the use of soil correctives on the growth and yield of soybeans (Glycine max L.) cultivated under various soil compaction levels, in greenhouse conditions. The experiment was conducted in pots (columns) of 0.2 m diameter PVC tubes, composed of two rings: the lower ring, 0.4 m in height, received the soil (dystrophic Red Latosol, clayey texture) without corrective and a density of 1.0 Mg m-3; and the upper ring, 0,2 m in height, received the treatments of soil correctives and density. The experimental design was fully randomized in a 4 x 6 x 2 factorial outline, being four soil density levels (1.0; 1.20; 1.40 and 1.60 Mg m-3), six soil correctives (without corrective, lime, calcium silicate, gypsum, lime + gypsum and calcium silicate + gypsum) and two cultivation systems of the soybean (with and without previous cultivation of palisade grass). Starting from 1.2 Mg m-3 of soil density the soybean growth and yield were decreased. The use of soil correctives and previous soil cultivation with palisade grass decreased the harmful effects of the soil compaction on the soybean growth and yield. For the treatments that received previous cultivation with palisade grass, the soybean growth and yield were higher with application of lime + gypsum and calcium silicate + gypsum.

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Evaluation of Growth Parameters and Biochemical Markers of Corn Plants Under Saline Stress

Journal of Agricultural Studies ◽

10.5296/jas.v7i4.15262 ◽

2019 ◽

Vol 7 (2) ◽

pp. 107

Author(s):

Ana Cláudia Graças Alves Viana ◽

Franciele Da Silva Quemel ◽

Janyeli Dorini Silva de Freitas ◽

João Paulo Francisco ◽

Antonio Nolla ◽

...

Keyword(s):

Sweet Corn ◽

Growth Parameters ◽

Membrane Damage ◽

Saline Stress ◽

Sodium Accumulation ◽

Stress Markers ◽

Malondialdehyde Content ◽

Nacl Concentration ◽

Red Latosol ◽

Corn Plants

This study aimed to investigate the effect of salinity on growth parameters and oxidative stress markers in leaves and roots of two sweet corn genotypes: BR 427III, obtained from Embrapa Milho e Sorgo, and Tropical Plus®, a commercial hybrid. The genotypes were kept in 15-L pots with typical dystrophic red latosol soil, and irrigated with NaCl solution (0, 25, 50, 100, 150 and 300 mM). At 105 days after planting, the samples were collected, immediately frozen in liquid nitrogen, and stored at -80 ºC for posterior analyses. After this period, it was verified that, while NaCl concentration increased, there was a decrease in leaf and root fresh and dry masses as well as in shot and root lengths of both evaluated genotypes. A decrease in the stem diameter of BR427III genotype plants and in the chlorophyll index of both genotypes was observed. Sodium accumulation in the root and leaves increased according to the stress severity; however, potassium content reduced in both roots and leaves. Proline content increased significantly in the leaves of both evaluated genotypes when exposed to higher concentrations of NaCl. On the other hand, malondialdehyde content decreased in leaves and root of Tropical Plus genotype, where an increase in electrolyte overflow from membrane damage caused by stress severity was observed.

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Biscogniauxia (Hypoxylon) Canker or Dieback in Trees

EDIS ◽

10.32473/edis-fr407-2017 ◽

2017 ◽

Vol 2017 (6) ◽

Author(s):

Claudia Paez ◽

Jason A. Smith

Keyword(s):

Water Stress ◽

Tree Species ◽

Soil Compaction ◽

Urban Areas ◽

Root Disease ◽

Poor Health ◽

Green Spaces ◽

Opportunistic Pathogens ◽

Wide Range ◽

Quercus Spp

Biscogniauxia canker or dieback (formerly called Hypoxylon canker or dieback) is a common contributor to poor health and decay in a wide range of tree species (Balbalian & Henn 2014). This disease is caused by several species of fungi in the genus Biscogniauxia (formerly Hypoxylon). B. atropunctata or B. mediterranea are usually the species found on Quercus spp. and other hosts in Florida, affecting trees growing in many different habitats, such as forests, parks, green spaces and urban areas (McBride & Appel, 2009). Typically, species of Biscogniauxia are opportunistic pathogens that do not affect healthy and vigorous trees; some species are more virulent than others. However, once they infect trees under stress (water stress, root disease, soil compaction, construction damage etc.) they can quickly colonize the host. Once a tree is infected and fruiting structures of the fungus are evident, the tree is not likely to survive especially if the infection is in the tree's trunk (Anderson et al., 1995).

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