Herbage Accumulation and Organic Reserves of Palisadegrass in Response to Grazing Management based on Canopy Targets

Author(s)

Pedreira, Carlos G. S. ; Silva, Valdson J. ; Pedreira, Bruno C. ; Sollenberger, Lynn E.

• Document type: Journal article
• Source: CROP SCIENCE; v. 57, n. 4, p. 2283-2293, JUL-AUG 2017.
• Web of Science Citations: 4

Abstract

Improved grazing management can increase the output of many tropical forage-livestock systems. Adjusted grazing management techniques have been proposed for producers that are willing to exploit the growth potential of available forage resources. The objective of this research was to describe and explain variations in herbage accumulation dynamics and organic reserves of cultivar Xaraes palisadegrass {[}Brachiaria brizantha (Hochst. ex A. Rich.) Stapf syn. Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster] under three grazing managements during spring and summer growing seasons of 2 yr. Pastures were grazed every 28 d (28-d) or at intervals defined by two levels of pre-graze canopy light interception (LI). These LI-based treatments are referred to as ``target grazing{''} (TG) at 95% LI and ``delayed grazing{''} (DG) at >= 97.5% LI. Pastures managed using TG and 28-d showed a similar herbage accumulation rate (HAR) (112 kg DM ha(-1) d(-1)) (P > 0.05), both lesser than DG (141 kg DM ha(-1) d(-1)). Although TG and 28-d showed similar daily HAR, stem proportion in the stubble was more variable for 28-d over the growing season. Stem proportion in the stubble was greater for DG (43.8%) and 28-d (40.4%) than for TG (34.2%). The TG management showed greater total non-structural carbohydrate (TNC) pools in roots (238 g m(-2)) than DG (136 g m(-2)) and 28-d (199 g m(-2)), suggesting less dependency of organic reserves. The TG was optimal strategy for intensive grazing management of Xaraes palisadegrass pastures. (AU)