ABSTRACT
O nitrogênio proporciona as maiores respostas no crescimento das gramas. Objetivou-se com este trabalho avaliar a extração total de macronutrientes pela grama bermuda em função de doses de nitrogênio. O experimento foi conduzido em propriedade de grama, localizada na cidade de Capela do Alto - SP. O delineamento experimental utilizado foi o de blocos ao acaso, com cinco tratamentos e quatro repetições. Os tratamentos foram constituídos por cinco doses de N: 0, 150, 300, 450 e 600 kg ha-1. Após cada corte da grama foram coletadas as aparas determinando-se a matéria seca e a concentração de macronutrientes. Com a colheita dos tapetes, determinou-se a matéria seca extraída com a retirada do mesmo e a concentração de nutrientes. A quantidade de macronutrientes extraídos foi calculada através do produto da massa seca pela concentração dos mesmos. Com a retirada das aparas cortadas durante o ciclo houve grande extração de nutrientes, 204; 18; 101; 22; 10 e 27 kg ha-1 para N, P, K, Ca, Mg e S, respectivamente. As quantidades de nutrientes necessárias para promover 100% de cobertura do solo pela grama são de 219,5; 27; 174,1; 31,8; 13,4; e 39,9 kg ha-1 de N, P, K, Ca, Mg e S, respectivamente.
Nitrogen provides the greatest answers in grass growth. The objective of this work was to evaluate the total extraction of nutrients by the bermudagrass due to nitrogen levels. The experiment was conduced in a grass property, located in Capela do Alto - SP. The experimental design was a randomized blocks, with five treatments and four replications. The treatments consisted of five N doses: 0, 150, 300, 450 and 600 kg ha-1. After each grass cut were collected clippings and determined dry matter and macronutrients content. After sod harvest, it was determined the dry matter extracted with the withdrawal of it and the nutrients concentration. The amounts of macronutrients were calculated by the product of dry weight by their concentration. With the withdrawal of clippings cut during the cycle there was a great extraction of nutrients, 204; 18; 101; 22; 10 and 27 kg ha-1 for N, P, K, Ca, Mg e S, respectively. The amount of nutrients needed to promote 100% of grass soil coverage are 219.5, 27, 174.1, 31.8, 13.4 and 39.9 kg ha-1, of N, P, K, Ca, Mg and S, respectively.