Franciele Caroline de Assis Valadão

Períodos de interferência de plantas daninhas na cultura do feijoeiro-comum (Phaseolus vulgaris L.)

Objetivou-se nesta pesquisa determinar os periodos de interferencia de plantas daninhas no feijoeiro-comum (Phaseolus vulgaris L.) cultivado em plantio direto, em Rolim de Moura-RO. Dois ensaios foram conduzidos simultaneamente; no primeiro a cultura permaneceu livre da competicao com plantas daninhas desde a emergencia ate os 7; 14; 21; 28; 35; 42; 49 e 64 dias; no segundo a cultura permaneceu em competicao com a comunidade infestante pelos periodos citados no primeiro ensaio. O delineamento utilizado foi de blocos ao acaso, com quatro repeticoes. A Digitaria horizontalis e Zea mays foram as especies que apresentaram maior importância. A D. horizontalis atingiu altas frequencias relativas, dominância relativa e densidade de ate 95,3%. A Z. mays apesar dos baixos indices de densidade e frequencia relativa, apresentou alta dominância relativa pelo grande acumulo de massa seca. O rendimento de graos do feijoeiro foi afetado pela convivencia com as plantas daninhas. Assumindo perdas de 5% no rendimento de graos do feijoeiro pela interferencia da comunidade infestante o periodo anterior a interferencia foi de quatro dias, onde nao foi necessaria a realizacao do controle. O periodo total de prevencao da interferencia foi de dezoito dias apos a emergencia (DAE) e o periodo critico de prevencao da interferencia situou-se entre os quatro e os dezoito DAE. Neste periodo ate 18 DAE a convivencia do feijoeiro com plantas daninhas ocasionou diminuicao no rendimento da cultura por competirem pelos recursos do meio, onde houve necessidade de serem controladas.

Estoque de nutrientes sob diferentes sistemas de uso do solo de Colorado do Oeste-RO

The replacement of forest by other land use can lead to significant losses in soil organic matter, changing its dynamic and the nutrients inputs and outputs of the system. The objective of this study was to assess nutrient stocks under different land use systems in Colorado do Oeste-RO. The agroforestry (teak, and cocoa), forestry (teak with five years), teak for eight years, farming areas (teak, cocoa and pasture) and pasture were the systems evaluated and the native forest was taken as reference. In each system three small trenches were dug, in which deformed and undeformed soil samples, at depths of 0 to 5, 5 to 10, 10 to 20 and 20 to 30 cm were taken. In these samples the nutrients N, P, K, Ca and Mg, organic matter, bulk density and clay content were determined. A completely randomized design with split plots and, three replications in each system was adopted. Differences were observed in soil nutrient stocks among the usage systems and with depth. The concentration of nutrients was influenced by the system. Ca was the nutrient most stored (2912.86 to 5188.48 kg ha-1) in all systems and K was the least(17.33 to 46.22 kg ha-1). The system of teak five years is the system which is closer to the forest, for the storage of nutrients.

Inoculação das sementes e adubações nitrogenada e molíbdica do feijoeiro-comum, em Rolim de Moura, RO

The aim of this study was to evaluate the effects of seed inoculation with Rhizobium tropici and nitrogen and molybdenum fertilization on the performance of the common-bean (Phaseolus vulgaris L.). A complete randomized block design with four replicates was used, in a factorial arrangement 2x2x2, with the combinations of absence and presence of seed inoculation and nitrogen (N) and molybdenum (Mo) fertilization. Seeds inoculation was just before sowing with a peat inoculante composed by the strain CIAT 899 (SEMIA 4077), N was provided at sowing (10 kg.ha-1) and coverage (50 kg.ha-1) when the plants showed the third trifoliate sheet expand and Mo was applied by foliar spraying with 60 g.ha-1 when plants were at beginning of flowering . No effect of treatments on the dry mass of roots and the number of pods per plant was observed. N fertilization reduced nodulation of plants, however, N fertilization lead to an increase in height and dry mass of bean shoots. It was also observed that plants fertilized with N but in the absence of Mo shoed heavier grains. The interactions between N and Mo fertilization with inoculation of seed negatively affected the leaf N content and the number of grains per pod. The inoculation of seed in beans provided grain yields similar to those provided by the treatment with N fertilization.

Variação nos atributos do solo em sistemas de manejo com adição de cama de frango

Poultry litter is an organic fertilizer with good agronomic characteristics, which serves well as conditioner of soil physical properties. In this sense, the objective of this study was to verify changes in soil properties in no-tillage systems with poultry litter. The study was conducted on a sandy loam Oxisol under continuous no-tillage in the last years, with rotation of mainly soybean, corn, cotton, and millet, with evaluations in three layers (0-10, 10-20, 20-30 cm), in three replications. The treatments consisted of a mineral fertilizer system (S2), application of raw poultry litter (S3), application of chicken manure compost (S4) and an untreated area with native vegetation (S1). The management systems induced the degradation of soil properties in relation to native vegetation (S1) in ascending order - S4, S2, S3, which was quantified by the reduced values of total carbon, aggregate diameter and stability, macroporosity, hydraulic conductivity saturated and higher values of density and resistance to penetration and microporosity. Raw poultry litter was more advantageous for the availability of total N and less efficient to ensure the soil physical quality. Composted chicken litter resulted in properties that were more similar to natural conditions.

Sistema radicular e componentes produtivos do girassol em solo compactado

The aim of this research was to verify morphologic and anatomic changes in the root system of the sunflower as well as in its productive attributes in function of the additional compression caused by tractor traffic in a typical Kandiustox (Oxisol). The research was conducted in the field, in 5 levels of compression: without additional traffic (C0); 1 (C1); 3 (C3); 6 (C6) and 11 (C11) paths of tractor. The physical properties of the soil and the distribution of the roots in the layers 0 – 0.05; 0.05 – 0.10; 0.10 – 0.15 and 0.15 – 0.20 m of depth were evaluated, besides the vegetal and reproductive characteristics and the anatomic changes in the roots. The soil compression by the machine traffic results in the reduction in the root area index (RAI) of the sunflower. The distribution of the sunflower’s roots occurs superficially in the soil’s profile and was reduced by a half when submitted to C11. The soil compression resulted in anatomic alterations in the roots, with changes in the diameter of the ducts, emerging of angle xilematic cells, crushing in the vascular cambium and occurrence of aerenchyma, typical in roots submitted to hypoxia. The plants presented less height, flower height, stem diameter, productivity and achenes mass, occurring a reduction in plant population. It was verified negative linear correlation between productivity and soil resistance to penetration, being 0.733 MPa a critical value, and positive linear correlation between macroporosity and RAI, with 0.264 m3∙m−3 considered as a critical value.

Lodo do curtimento e sua influência na produção de mudas de paricá ( Schizolobium amazonicum ) e nas propriedades químicas do solo

O objetivo deste estudo foi verificar a influencia do lodo do curtimento nas propriedades quimicas do solo e nas caracteristicas morfologicas e nutricionais de mudas de parica. O experimento foi realizado em casa de vegetacao em delineamento inteiramente casualizado, em cinco repeticoes, tendo como substrato um cambissolo humico, o qual foi caracterizado quimica e granulometricamente; de posse desses resultados o solo foi corrigido previamente com calcario e NPK. Apos 100 dias de observacao foram analisadas as variaveis quimicas do solo (pH, H+Al, Al3+, Ca, Mg, P, K, Na, S, Cr3+, CO, SB, CTC, V, RAS e PST), a morfologia da planta [altura (H), diâmetro do caule (DC), numero de folhas completas, comprimento da raiz principal (CR) e biomassa seca], bem como as concentracoes de N, P, K, Ca, Mg, S, Cr3+ e Na na planta. O lodo de curtimento foi utilizado como complemento nutricional nas doses de 0,0; 1,5; 3,0; 4,5 e 6,0 g kg-1. O lodo de curtimento tem potencial como corretivo de acidez do solo, com aumento pouco expressivo dos indicadores de salinidade, sodicidade e do teor de Cr3+ disponivel. No entanto, o uso do lodo nao afetou as caracteristicas morfologicas das mudas de parica, porem, propiciou aumento nos teores K e S na parte aerea e de Na e S na raiz. Os maiores teores de nutrientes no parica foram obtidos com 6,0 g kg-1 de lodo de curtimento, contudo, nao foi possivel otimizar uma dose para a maxima produtividade de mudas de parica com as doses utilizadas.

Interrelationship between cotton parameters and soil chemical properties in Central Brazil

Classical geostatistical techniques and Geostatistics are important tools to correlate, linearly and spatially, vegetal productivity with the soil properties. Spatial and Pearson correlations between the attributes of the cotton plant and the soil properties were used in Campo Novo do Parecis, State of Mato Grosso, Brazil, in 2015 to determine the variability of plant productivity and soil chemical properties in the Savannah of Mato Grosso. A geostatistical grid was established for collection of data of the soil and plant, with 100 sampling points, in a plot with cotton crop. Soil was classified a Typic Tropustox. The variability expressed by the coefficient of variation was predominantly low to moderate for all soil chemical properties and productive variables of cotton. The absence of spatial dependence for soil chemical properties, except pH, indicated that spatial variations should be considered for soil sampling design. Kriging maps for the productive attributes of cotton showed that they have similar spatial distribution patterns in the crop. The productive attributes of the crop with direct relationship on the productivity of seed cotton were the number of reproductive branches and the boll mass, both linear and spatial.