Growth and Production of Crambe Submitted to Doses of Nitrogen and Potassium

The dependence on non-renewable fuels of countries around the world increased the interest for the gradual replacement of fossil fuels with renewable ones. Thus, several development programs for the use of renewable sources for power generation have been created and, in this perspective, biofuels have been highlighted. Crambe is an alternative crop for the production of biodiesel due to its rusticity, precocity, high oil content and adaptability to different climates. Optimum management practices of fertilizer use in crambe cultivation are little known and there are no specific recommendations for its fertilization. Therefore, the objective of this research was to study the effects of mineral fertilizers concerning the nitrogen and potassium elements in the growth and production of crambe. The experiment was installed in a greenhouse, with a completely randomized design. Nitrogen doses used were 30, 60, 90 and 120 kg·ha-1and 50, 75, 100 to 125 kg·ha-1 for potassium. The increase in production was directly proportional to the increase in nitrogen levels. The potassium doses did not cause significant effect on the growth of crambe.

Melon Seedlings Phytomass under Poultry Litter Biochar Doses

The use of organic waste for the preparation of seedling substrates is an important environmental and economic option. In this perspective, substrates using biochar emerges as an alternative for seedling production due to their favorable physical and chemical characteristics. The present study aimed to evaluate the efficiency of doses of poultry litter biochar as a substrate constituent for the production and quality of the seedlings. The work was conducted in a semi protected environment, belonging to the Federal University of Campina Grande—UFCG. The statistical design used was completely randomized in a 6 × 2 factorial scheme, consisting of 6 doses of biochar (0, 4, 8, 12, 16 and 20 t∙ha−1) and two varieties of melon (Yellow and Hales Best Jumbo) with 4 repetitions totaling 48 experimental units. The fresh and dry plant phytomass mass (aerial, roots and total), root length and the quality of seedlings were evaluated. It was concluded that the addition of poultry litter biochar to the substrate was beneficial, promoting an increase in the analyzed seedling variables, being the ideal dose for good development of melon seedlings 12 t∙ha−1. The Yellow variety presented a better response than the Hales Best Jumbo to the charcoal application. Considering the advantages of the use of poultry litter biochar on the substrate composition, found in the present study, its utilization constitutes a viable alternative for the development of melon seedlings and for the environmental disposal of the poultry litter.

Corn Production for Silage Subjected to Potassium Fertilization and Water Depths

This study was carried out with the objective of evaluating the effect of water depths and potassium fertilizer levels on corn yield for silage. The experimental design was a randomized block design in a split-plot with six water depths based on crop potential evapotranspiration (ETcp) in levels: 0.25;0.50;0.75;1.00;1.25 and 1.50 ETcp, and six amounts of potassium, 0, 20, 40, 60, 80 and 100 kg·ha-1, in four replicates. The irrigation system was dripped. Before sowing was applied to the soil to nitrogen (N) and phosphate (P) fertilizers, corn was sown ten days after the fertilization using seeds from hybrid AG 1051. Manual harvesting of ears occurred 67 days after sowing. Production variables observed were fresh matter of plant with (FPMwiths) and without (FPMwithouts) the ears. The fresh matter of plant with and without the ears was influenced significantly by factors analyzed, the 1% level of probability by F test. The water depths in irrigation that maximized the physiological parameters of plants as FPMwiths and FPMwithouts were, respectively, 690 mm and 766.7 mm. The quantitative potassium to maximize physiological parameters of FMP with ears and FMP without ears was, respectively, 104.75 kg ha-1 and 52.1 kg ha-1.

Crambe (<i>Crambe abyssinica</i>) Cultivation under Different Levels of Fertilization with Nitrogen, Phosphorus and Potassium

The effects of fertilization on crambe are poorly understood;in this sense, this study aimed to evaluate the crambe growth under different levels of nitrogen (0, 40, 80, 120 kg&#183;ha-1), phosphorus (0, 50, 100, 150 kg&#183;ha-1), and potassium (0, 30, 60, 90 kg&#183;ha-1) in a greenhouse. The height of the plants, the production of dried biomass and that of 1000 grains of crambe were evaluated. The height of the plants was impaired as a function of increasing doses of nitrogen. The interaction of nitrogen and phosphorus in the crambe crop increased the number of grains and dry shoot biomass. The growth and yield of the crop were not influenced by the use of potassium in mineral fertilization.

Influence of Bentonite and MB4 on the Chemical Characteristics of an Oxisol

The growing concern with the quality of life and the environment, due to the degradation of natural resources and their contamination, mainly with agrochemicals, led to the emergence of a sustainable or alternative agriculture. The objective of this study was to evaluate the effect of the addition of increasing doses of bentonite and MB4 on the availability of nutrients to the soil. The experiment consisted of a 4 × 4 factorial, bentonite doses (0, 30, 60 and 90 t&#8901;ha&#8722;1) and MB4 doses (0, 3, 6 and 9 t&#8901;ha&#8722;1) with three replications. The soil mixtures with the treatments were conditioned in the plastic pots, incubated for 90 days in a greenhouse, and chemically analyzed. Data were submitted to analysis of variance and comparison of means by the Tukey test. Increasing doses of bentonite and MB4 promoted an increase in the calcium (Ca), magnesium (Mg) in the soil sample either alone or the mixture of two factors, except for the mixture of the Ca Mg doses. Increasing doses of bentonite increased the cation exchange capacity of the soil, favoring the availability of nutrients in the soil. The increasing doses of MB4 favored the increase of the pH values and, consequently, decreased the soil potential acidity values for the applied bentonite doses. On the other hand, these treatments decreased the cation exchange capacity of the soil.

Tolerance to Salinity of Sesame Genotypes in Different Phenological Stages

The sesame crop is usually avoided in salt-affected areas because of the various effects of saline stress on plants. Besides varying between species, salinity effects are known to vary for genotypes of the same species as well as plant development stages. Thus, through the irrigation of plants with saline water, this study evaluates tolerance to saline stress of new sesame genotypes in different phenological stages. Three experiments were carried out under greenhouse conditions, using the sesame genotypes BRS Seda, LAG-927561 and LAG-26514. Water with different levels of electrical conductivity (ECw = 0.6, 1.6, 2.6, 3.6 and 4.6 dS m-1) was used to irrigate plants during germination and initial growth stages, as well as the entire crop cycle. Tolerance to saline stress (3.6 dS m-1) during growth and production stages was also studied. Salinity did not affect sesame germination, but seedling growth was hindered from the ECw of 1.6 dS m-1 onwards, and plant height was the most affected growth variable. Seed production is affected by salinity, regardless of the phenological stage in which plants are exposed to salinity. The strains LAG-927561 and LAG-26514 show promising signs in studies on adaptation to saline stress.

Growth of Pepper under Different Concentration of the Solutions Used in the Hydroponic System

Water availability is a fundamental condition for sustainable agriculture. However, a satisfactory water condition is not always possible in terms of quantity and quality in certain regions, such as the Brazilian semi-arid region. Thus, the purpose of this extremely important research was to evaluate the growth of cv. All Big with six combinations of wastewater plus saline (WW + SW) and two nutrient solution percentages, in a low-cost hydroponic system. The experiment was carried out in a greenhouse at the Department of Agricultural Engineering at Federal University of Campina Grande. A completely randomized experimental design was used, with treatments arranged in a factorial scheme (6 × 2), with 5 replications, being the treatments composed by the combination of six proportions of wastewater with saline water (50%/50%;60%/40%;70%/30%;80%/20%;90%/10%;100% of wastewater) and two nutrient solution concentration (80% and 100%), totalizing 60 experimental units. The biometric variables were analyzed at 55 and 96 days after sowing, namely: plant height (PH), stem diameter (SD), leaf number (LN) and leaf area (LA). The interaction between the concentration of the nutrient solution and the ratio of the saline water with wastewater was influenced in the behavior of peppers (cv. All Big) biometric variables. The nutrient solution prepared at 80% of its normal concentration had better performance in the development of plants when mixed with the proportions of water containing more wastewater. The proportion 30% saline water and 70% wastewater (30/70) with concentration of 80% of the nutrient solution obtained better satisfactory results in the studied biometric variables.

Using Poultry Litter Biochar and Rock Dust MB-4 on Release Available Phosphorus to Soils

Highly weathered soils in areas from Brazil are acidic soils, typically characterized by poor fertility, particularly with low soil phosphorus level. This laboratory experiment was carried out to evaluate the influences of biochar, made from the poultry litter and MB-4, rock dust from grinding of silicate rocks in increasing the available soil phosphorus on Ultisol, Oxisol and Entisol. Thus, one experiment involving soils incubation was conducted in laboratory, during 100 days. The treatments consisted of rock powder, MB-4 and poultry litter, biochar, evaluated by the base saturation method, with correction levels from 40% to 80% for Ultisol and Entisol and from 20% to 80% for Oxisol and three replicates. After the incubation period, the soil samples were analyzed in relation to available phosphorus in the soil. The results of this study confirmed that the biochar prepared from the poultry litter through slow pyrolysis was a potential source of phosphorus, particularly to weathered soils. Biochar released phosphorus into the soils. The biochar could be used in the improvement of available phosphorus for the three soils analyzed. During the incubation period, 100 days, the application of increasing doses of MB-4 in soils there was no improvement in the available soil phosphorus. MB-4 was not a source of phosphorus to the soil in a short term.

Effect of Copper, Zinc, Cadmium and Chromium in the Growth of Crambe

Crambe is a promising crop for biodiesel production. However, there is no much information available about techniques and research regarding the best performance in different regions to explore its potential. The objective of this study was to evaluate the effect of cadmium, chromium, copper and zinc in the development of crambe. The study was carried out in a greenhouse and it consisted of four independent experiments in completely randomized design, with three replications. Four metals with five levels were applied: 0, 10, 15, 20 and 25 mg·kg-1 for copper, cadmium, chromium;and 0, 20, 30, 40 and 50 mg·kg-1 for zinc, in order to evaluate the growth of crambe. Data were subjected to analysis of variance and comparison of means by Tukey test at 1 and 5% significance. Despite doses of cadmium, chromium, copper and zinc in growing crambe have influenced in some of the evaluated variables of the plants, in general, their development was similar in relation to doses and the metals applied. The importance of cultivating crambe is related to grain production, based on this, copper and cadmium decreased this production.