The objective of this study was to evaluate the effect of omission of macronutrients on dry matter production and on the nutritional status of sunflower cv. BRS 122. The experiment was carried out in a greenhouse, in ...The objective of this study was to evaluate the effect of omission of macronutrients on dry matter production and on the nutritional status of sunflower cv. BRS 122. The experiment was carried out in a greenhouse, in randomized blocks, with seven treatments corresponding to the Hoagland & Arnon standard solution (1950) and the individual omission of N, P, K, Ca, Mg and S, in three replicates. After 50 days of sowing, the dry matter and the nutritional status of the plants were evaluated. The omission of N, P, K, Ca, Mg and S limited the dry mass production of sunflower cv. BRS 122 in relation to the complete solution, besides causing nutritional imbalance due to the interaction between the nutrients. The omission of the macronutrients K, Ca, and Mg caused the higher imbalances in the plants, highlighting the elevated N contents in these treatments comparing to the complete solution.展开更多
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 ag...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⋅ha−1) and MB4 doses (0, 3, 6 and 9 t⋅ha−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.展开更多
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 s...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<sup>-1</sup>and 50, 75, 100 to 125 kg·ha<sup>-1</sup> 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.展开更多
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 obje...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.展开更多
文摘The objective of this study was to evaluate the effect of omission of macronutrients on dry matter production and on the nutritional status of sunflower cv. BRS 122. The experiment was carried out in a greenhouse, in randomized blocks, with seven treatments corresponding to the Hoagland & Arnon standard solution (1950) and the individual omission of N, P, K, Ca, Mg and S, in three replicates. After 50 days of sowing, the dry matter and the nutritional status of the plants were evaluated. The omission of N, P, K, Ca, Mg and S limited the dry mass production of sunflower cv. BRS 122 in relation to the complete solution, besides causing nutritional imbalance due to the interaction between the nutrients. The omission of the macronutrients K, Ca, and Mg caused the higher imbalances in the plants, highlighting the elevated N contents in these treatments comparing to the complete solution.
文摘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⋅ha−1) and MB4 doses (0, 3, 6 and 9 t⋅ha−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.
文摘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<sup>-1</sup>and 50, 75, 100 to 125 kg·ha<sup>-1</sup> 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.
文摘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.
