Helon Hébano de Freitas Sousa

Nitrogen and potassium in production, nutrition and water use efficiency in wheat plants

Wheat ( Triticum aestivum L.) is a cereal used in food and feed for its nutritional properties. For nitrogen and potassium management, efficient use of water is required for greater availability and transportation of these nutrients. The objective of this study was to evaluate the effect of combinations of nitrogen and potassium doses in production, nutrition and water use efficiency in wheat. The experiment was held in a greenhouse with 8-dm3 pots using Oxisol collected at a depth of 0-0.2 m under Cerrado vegetation. Base saturation was raised to 60%. The experimental design was a randomized block in a 5x5 factorial arrangement with five doses of nitrogen (0, 100, 200, 300 and 400 mg dm-3) and potassium (0, 90, 180, 270, 360 mg dm-3) with four replications. Soil moisture was maintained by an auto-irrigation system (3 kPa pressure). The experiment was collected at 95 days after plant emergence. We evaluated the dry mass of ears, shoots and roots, the total dry matter, nitrogen and potassium in grains, and the consumption and efficiency in water use. An analysis of variance and regression test at 5% probability was conducted using SAS statistical software (SAS Institute, Inc., Cary, North Carolina). The nitrogen and potassium alone increased the dry mass of ears by 31.47% and 20.91%, respectively. There was an interaction of nutrients on the dry mass of the shoots and the total dry matter. Potassium increases the concentration of nitrogen. Nitrogen and potassium promote gains in production, nutrition and water use efficiency. Trigo ( Triticum aestivum L.) es un cereal utilizado en la alimentacion humana y animal por sus propiedades nutritivas. En la gestion de nitrogeno y potasio, el uso eficiente del agua es necesaria para la mayor disponibilidad y el transporte de estos nutrientes. Este estudio tuvo como objetivo evaluar el efecto de las combinaciones de nitrogeno y potasio en la produccion, la nutricion y la eficiencia en el uso del agua en trigo. El experimento se realizo en un invernadero con recipientes de 8 dm3. Usando Oxisol, recogido a una profundidad de 0-0,2 m de area bajo la vegetacion del Cerrado. La saturacion de bases se aumento a 60%. El diseno experimental fue de bloques al azar en arreglo factorial 5x5 con cinco dosis de nitrogeno (0, 100, 200, 300 y 400 mg dm-3) y potasio (0, 90, 180, 270 y 360 mg dm-3) con cuatro repeticiones. La humedad del suelo se mantuvo con un sistema autoirrigante (mantenido en el potencial de -3 kPa). El experimento foe cosecho despues de 95 dias de la emergencia. Se evaluaron la materia seca de las espigas, brotes, raices, y materia seca vegetal total; nitrogeno y potasio en granos; el consumo y la eficiencia en el uso del agua. Las variables se sometieron a analisis de varianza y prueba de regresion al 5% de probabilidad por el programa estadistico SAS. El nitrogeno y potasio, por separado, aumentaron el peso seco de las espigas, con incrementos de 31,47 y 20,91%, respectivamente. Hubo interaccion de nutrientes a la masa seca de la parte aerea y total. El potasio aumenta la concentracion de nitrogeno. El nitrogeno y el potasio promueven ganancias en la produccion, la nutricion y la eficiencia en el uso del agua.

Interaction between nitrogen and potassium in fertilization of the piatã grass (Urochloa brizantha): productive and phytometric characteristics

In this study, the aim was to determine the phytometric and productive features of Urochloa brizantha cv. BRS Piatã cultivated in Oxisol under the influence of the nitrogen and potassium doses applied. The completely randomized experimental design was adopted in a 5x5 factorial scheme, supplying five doses of nitrogen (0, 100, 200, 300 and 400 mg dm -3 ) and five doses of potassium (0, 90, 180, 270 and 360 mg dm -3 ), with four replications. Three shoots were cut at 30-day intervals. Plant height, number of leaves, number of tillers, leaf dry mass, stem dry mass and leaf /stem ratio were assessed. The leaf dry mass at the 370, 287 and 259 mg dm -3 doses of nitrogen in combination with the 360 mg dm -3 potassium doses revealed the biggest yields (7.8, 16.9 and 11.5 g pot -1 ) for the first, second and third cuts, respectively. Therefore, it was revealed that nitrogen and potassium affected the phytometric characteristics in this grass in an isolated manner by doses of nitrogen potassium. The nitrogen and potassium doses interacted positively to present significantly productive characteristics at all the three cutting procedures performed in the Piatã grass when the nitrogen to potassium ratio was maintained at about 1: 1.

Agronomic performance of Safflower genotypes (Carthamus tinctorius L.) under different soil bulk density levels in the Oxisol of the Cerrado

Federal University of Mato Grosso - UFMT Institute of Agricultural and Technological Sciences, 5055 Students Avenue