Guar root and shoot growth as affected by soil compaction

Guar (Cyamopsis tetragonoloba L.) is commonly grown in arid lands, because of its high drought-tolerance. However, soil compaction may be a limiting factor to its growth. This study aimed to evaluate the guar growth, according to the soil penetration resistance (0.20 MPa, 0.33 MPa, 0.50 MPa, 0.93 MPa and 1.77 MPa, in a layer with depth between 0.15 m and 0.20 m), in a Rhodic Acrudox soil. The shoot and root dry mass, root length by the Q1/2 index (mechanical soil penetration resistance in which the root growth is reduced by 50 %) and root diameter were evaluated. The impairment of the guar shoot growth begins when the penetration resistance is greater than around 1 MPa. The soil compaction alters the distribution of guar roots in the soil profile, concentrating them in the 0.15 m layer, but it does not prevent roots from penetrating this layer and developing in depth. The root diameter increases in the compacted layer. A soil penetration resistance of up to 1.77 MPa does not influence the root length density below the compacted layer, as well as the total root length density of guar. Although the guar Q1/2 index is greater than 1.58, the shoot and root dry mass are impaired

Characterization of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time

Objective The objective was to characterize the fermentative and microbiological profile of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time. Methods The experimental design consisted of a randomized block design with four and six wrapping layers (100 and 150 microns in total. respectively) allocated in the main plots, through repeated measures analysis (30, 60, and 90 days of storage) with four replicates. Results The storage time and number of wrapping layers did not show changes in the population of Clostridium and lactic acid bacteria. A decrease was observed in the enterobacteria population with an increase in the storage period in the two wrapping layers studied. Upon opening of the haylage at 30 days, the population of Bacillus was lower in haylages made with six layers of wrapping (3.63 log colony forming units/g). No growth of Listeria sp. or Salmonella sp. was observed during the experimental period. The fungal genera with a greater occurrence were Penicillium sp. and Fusarium sp. The following mycotoxins were not detected: ochratoxin A, fumonisins, and zearalenone. Relative to the organic butyric, propionic, and acetic acids, the haylages presented a low concentration of lactic acid; this may have prevented a drop in the pH, which was high when the silos were opened (5.4). The levels of ammoniacal nitrogen and soluble carbohydrates presented no variation among the number of wrapping layers, with an overall average of 35.55 and 38.04 g/kg. Conclusion Tifton 85 bermudagrass haylage wrapped with four and six layers presented adequate fermentation and microbiological characteristics in the evaluated periods

Safflower root and shoot growth affected by soil compaction

<div><p>ABSTRACT Safflower (Carthamus tinctorius L.) is a commercial seed crop grown for its good yield of high-quality oil. It is tolerant to water stress but may be sensitive to soil compaction. The aim of this study was to assess safflower growth under different degrees of soil compaction at depths of 0.15 m to 0.20 m. The experiment was carried out in PVC pots constructed from three rings. Five levels of penetration resistance (0.20, 0.33, 0.50, 0.93, and 1.77 MPa) were applied in the intermediate ring, and two safflower genotypes, IMA-4904 and IMA-2106, were examined. There was no difference between safflower genotypes with respect to their resistance to soil compaction, which reduced root length density in the compacted layer and changed the root distribution in the soil profile, but did not prevent the roots from crossing the compacted layer and developing in depth. Increased soil bulk density in the compacted layer increased root diameter of the IMA-2106 genotype. Penetration resistance levels over 0.20 MPa (density of 1.2 mg.dm–3) limited safflower root development. The maximum safflower growth occurred when the soil penetration resistance was 0.86 MPa. In this study, the Q1/2 index was higher than 1.77 and 1.55 for the IMA-2106 and IMA-4904 genotypes, respectively. Hence, safflower has proven to be tolerant to soil compaction, and stands out as a species with potential to decrease soil bulk density.</p></div

Guar root and shoot growth as affected by soil compaction

<div><p>ABSTRACT Guar (Cyamopsis tetragonoloba L.) is commonly grown in arid lands, because of its high drought-tolerance. However, soil compaction may be a limiting factor to its growth. This study aimed to evaluate the guar growth, according to the soil penetration resistance (0.20 MPa, 0.33 MPa, 0.50 MPa, 0.93 MPa and 1.77 MPa, in a layer with depth between 0.15 m and 0.20 m), in a Rhodic Acrudox soil. The shoot and root dry mass, root length by the Q1/2 index (mechanical soil penetration resistance in which the root growth is reduced by 50 %) and root diameter were evaluated. The impairment of the guar shoot growth begins when the penetration resistance is greater than around 1 MPa. The soil compaction alters the distribution of guar roots in the soil profile, concentrating them in the 0.15 m layer, but it does not prevent roots from penetrating this layer and developing in depth. The root diameter increases in the compacted layer. A soil penetration resistance of up to 1.77 MPa does not influence the root length density below the compacted layer, as well as the total root length density of guar. Although the guar Q1/2 index is greater than 1.58, the shoot and root dry mass are impaired.</p></div

Microbiota da água residuária de suinocultura na estação de tratamento e área de produção de capim-tifton 85

The objective of this study was to evaluate the effects of biodigester treatment on the microbiological characteristics of swine wastewater (SW) at the production and storage sites, and to characterize and compare the microbiological composition of the soil, organic matter, and plants in the area of hay and haylage production. The area has been planted with Tifton 85 grass for eight years; and is exclusively intended for hay and haylage production, SW was used as the only fertilizer source. The experimental design was completely randomized with subdivided plotsin timeand five replications; the plots were the main areas of the SW in natura (affluent), the biodigester outlet (effluent), the storage pond, and the area of Tifton 85 production, which included the soil, plant residue on the soil surface (organic matter), and the aerial parts of the grasseswith subplots in the rainy and dry seasons. The microbial count in the SW was reduced during the treatment process, with higher counts in the affluent, and lower countsin the effluent and storage pond. The SW treatment was efficient in reducing the microbial population. The populations of Bacillus and Clostridiumwere influenced by the season of the year, with larger populations during the rainy season (summer) than during the dry season (winter). The mold genera identified in the SW area were Penicillium, Rhizopus, Fusarium, Helminthosporium, and Phoma. The genera Penicillium, Rhizopus, Fusarium, Cladosporium, Helminthosporium, Bipolaris, Phoma, Aspergillus, and Trichoderma were found in the area of Tifton 85 production.O objetivo deste estudo foi avaliar a eficiência do tratamento do biodigestor nas características microbiológicas da água residuária de suinocultura (ARS), no local de produção até o local de armazenamento, bem como caracterizar e comparar a composição microbiológica do solo, matéria orgânica e planta, em uma área de produção de feno e pré-secado. A área de capim-tifton 85 foi implantada há oito anos e é destinada exclusivamente à produção de feno e pré-secado, utilizando como única fonte de adubação a aplicação da ARS. O delineamento experimental foi inteiramente casualizado com parcelas sub divididas, com cinco repetições, sendo as parcelas principais: ARS in natura (afluente), a ARS após a saída do biodigestor (efluente) e a ARS na lagoa de armazenamento; além da área de produção do capim-tifton 85: solo, resíduo das plantas na superfície do solo (matéria orgânica) e parte aérea da planta. As sub parcelas foram: a estação chuvosa e a estação seca. Os resultados mostram que a carga microbiana presente na ARS foi reduzida durante o processo de tratamento, com maiores contagens no afluente, e menores no efluente e lagoa de armazenamento. O tratamento da ARS foi eficiente na redução da população microbiana. A população de Bacillus e Clostridium é influenciada pela estação do ano, com maiores populações na estação chuvosa (verão) em relação à estação seca (inverno). Os gêneros de bolores identificados na área de produção da ARS foram Penicillium, Rhizopus, Fusarium, Helminthosporium, Phoma. Na área de produção do capim-tifton 85 foram encontrados os gêneros Penicillium, Rhizopus, Fusarium, Cladosporium, Helminthosporium, Bipolaris, Phoma, Aspergillus, Trichoderme

ATRIBUTOS QUÍMICOS DE UM LATOSSOLO VERMELHO EUTROFÉRRICO EM FUNÇÃO DA ADUBAÇÃO SILICATADA

Calcium silicate when applied to the soil may cause changes in the chemical soil since it is a source of silicon, calcium and magnesium. The objective of this study was to evaluate the effect of calcium silicate on the chemical properties of an Oxisol. The experiment was conducted in a greenhouse with a randomized complete block design, with five doses of calcium silicate (0, 1.2, 2.4, 4.8 and 9.6 t ha-1) and four replicates. We evaluated the soil chemical properties. Silicon fertilization increases the content of Si, Ca and Mg, pH values, and SB and V%, and reduces the potential acidity (H + Al) of the soil

Efeitos da aplicação de silicato na fertilidade do solo e rendimento do trigo

An improvement in soil chemical properties and crop development with silicate application has been confirmed in several plant species. The effects of silicate application on soil chemical properties and wheat growth were investigated in the present study. The experiment was carried out in 8-L plastic pots in a greenhouse. Treatments were arranged in a randomized block design in a 3 × 5 factorial: three soils [Rhodic Acrudox (Ox1), Rhodic Hapludox (Ox2) and Arenic Hapludult (Ult)] and five silicate rates (0, 1, 2, 4 and 6 Mg ha–1 of calcium/magnesium silicate), with four replications. The plant length, number of spikes per pot, shoot dry matter and grain yield, were measured after 115 days of wheat (Triticum aestivum L.) growth. Changes in the soil chemical properties (pH, H+ + Al3+, Al3+, P, K, Ca, Mg, Si, Cu, Zn, Fe and Mn) were analyzed after wheat harvest. Application of calcium/magnesium silicate reduces the potential acidity (H+ + Al3+) and Al3+ phytotoxic; and increases the soil pH, available Ca, Mg and Si, cation exchange capacity (CEC) and soil base saturation. Silicate application did not affect the available P, exchangeable K and availability of micronutrients (Cu, Zn, Fe and Mn) in the three soils. The application of calcium/magnesium silicate in an acid clayey Rhodic Hapludox improves the development and yield of wheat; however, the silicate application in soil with pH higher to 5.3 and high Si availability does not affect the agronomic characteristics and grain yield of wheat.  Melhorias das propriedades químicas do solo e do desenvolvimento das culturas com aplicação de silicato foi confirmado em várias espécies de plantas. Os efeitos da aplicação de silicato nas propriedades químicas do solo e crescimento do trigo foram investigados no presente estudo. O experimento foi realizado em vasos plásticos de 8 L em estufa. Os tratamentos foram dispostos em um delineamento em blocos casualizados, em esquema fatorial 3 × 5: três solos [Latossolo Vermelho eutroférrico (LVef), Latossolo Vermelho distroférrico (LVd) e Argissolo Vermelho-Amarelo eutrófico (PVAe)] e cinco doses de silicato (0, 1, 2, 4 e 6 Mg ha-1 de silicato de cálcio / magnésio), com quatro repetições. O comprimento da planta, número de espigas por vaso, matéria seca e rendimento de grãos, foram medidos após 115 dias de crescimento do trigo (Triticum aestivum L.). As alterações nas propriedades químicas do solo (pH, H ++ Al3+, Al3+, P, K, Ca, Mg, Si, Cu, Zn, Fe e Mn) foram analisados após a colheita. A aplicação de silicato de cálcio/magnésio reduz a acidez potencial (H+ + Al3+) e Al3+ fitotóxico; e aumenta o pH do solo, Ca, Mg e Si disponível, capacidade de troca catiônica (CTC) e saturação por bases. Aplicação de silicato não afetou o P disponível, K trocável e disponibilidade de micronutrientes (Cu, Zn, Fe e Mn) nos três solos. A aplicação de silicato de cálcio/magnésio em um Latossolo Vermelho argiloso ácido melhora o desenvolvimento e a produtividade do trigo; no entanto, a aplicação de silicato em solos com pH superior a 5,3 e alta disponibilidade Si não afeta as características agronômicas e produtividade de grãos do trigo

Atributos químicos do solo e desenvolvimento da cultura do trigo em função da adubação silicatada

A aplicação de silicato de cálcio pode promover melhorias nos atributos químicos do solo e, consequentemente, incrementar a disponibilidade de nutriente para as plantas. Neste trabalho objetivou-se avaliar o efeito da aplicação de doses crescentes de silicato de cálcio sobre atributos químicos do solo e no desenvolvimento da cultura do trigo. Foi realizado um experimento em casa de vegetação, em vasos com Latossolo Vermelho eutroférrico (LVef). O delineamento experimental foi em blocos casualizados, com cinco doses de silício na forma de silicato de cálcio (0; 1,2; 2,4; 4,8 e 9,6 t ha-1) com quatro repetições. Posteriormente, foram avaliados a massa de matéria seca da parte aérea, altura de planta, número de perfilho, produção, e os atributos químicos do solo: pH, Si, P, K, Ca, Mg, H + Al, SB, CTC e V%. A massa de matéria seca da parte aérea, altura de plantas, número de perfilho e produção não foram influenciadas pela adubação com silicato de cálcio. Contudo a adubação silicatada elevou os teores de Si, P, K, Ca e Mg e os valores de pH, SB, CTC e V%, e reduziu (H + Al) do solo