Effect of different fertilization protocols and cutting intensity on marandu grass
State University of Southwest of Bahia, BR45700-000, Itapetinga, Bahia, Brazil
*Correspondence: amanda.s.ri@hotmail.com
Abstract:
The present study aimed to investigate the effects of different cutting intensities, combined with different fertilizations, on the productive characteristics, carbohydrate concentration and photosynthetic pigments of Urochloa brizantha cv. Marandu. It was carried out in a completely randomized design in which five fertilization treatments were evaluated: a control treatment without fertilizers and four fertilizer combinations (PK; NP; NK; NPK). The cutting intensities tested were 10 and 20 cm in height. There were four replicates per treatment. Plastic pots of 12 liters were used as experimental units, which were filled with 10 dm³ of soil with a clayey-sandy loam texture. Seeds of Urochloa brizantha cv. Marandu, with 80% of cultural value, were used. There was a significant difference for fertilization with NP and NPK, which resulted in higher production of shoot dry mass (PMSPA), residue dry mass (PMSRE) and root dry mass (PMSRA)in addition to higher concentrations of total soluble sugars in the shoot, residue and root. At a cutting intensity of 20 cm, NK and NPK fertilizations provided the highest levels of chlorophyll a. On the other hand, when analysing chlorophyll b and total chlorophyll at an intensity of 10 cm, NK fertilization presented the highest levels. However, at an intensity of 20 cm, NPK fertilization presented the highest levels of chlorophyll b, carotenoids and total chlorophyll. Regarding starch content, the PK and NPK treatments presented lower values at an intensity of 10 cm, while, at an intensity of 20 cm, NK fertilization resulted in the lowest starch content. Given the results presented, it is concluded that the use of NP fertilization at an intensity of 20 cm is recommended because it provides better indices on photosynthetic pigments, productive characteristics and total soluble sugar contents of Urochloa brizantha cv. Marandu.
Key words:
chemical fertilization, cutting intensity, grasses