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Distribution of Nutrients Among Soil–Plant Pools in ‘Tifton 85’ Bermudagrass Pastures Grazed at Different Intensities
Author(s) -
Liu Kesi,
Sollenberger Lynn E.,
Silveira Maria L.,
Vendramini João M.B.,
Newman Yoana C.
Publication year - 2011
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2010.04.0209
Subject(s) - grazing , tifton , cynodon dactylon , agronomy , nutrient , cynodon , biology , grassland , litter , soil water , forage , ecology
Choice of grazing intensity (i.e., stocking rate or grazed sward height) has an important role in the functioning of grassland ecosystems; however, the effect of grazing intensity on size and relative importance of various grassland nutrient pools is not well understood. The objective of this 2‐yr study, conducted on soils from the Plummer and Sparr series, was to determine the effect of stubble height after grazing (SH) on nutrient distribution among plant and soil (0‐ to 20‐cm depth) nutrient pools in ‘Tifton 85’ bermudagrass ( Cynodon spp.) pastures. Swards were stocked rotationally and grazed every 28 d to SH of 8, 16, and 24 cm. Green herbage, plant litter, and root–rhizome pool masses increased as SH increased. Plant nutrient concentrations (g kg −1 ) were relatively unresponsive to SH, but soil C and N concentrations increased by 23 and 34%, respectively, as SH increased. Nutrient content (kg ha −1 ) of all plant pools increased as SH increased, mainly a function of increasing pool mass. Soil pool P and K content (Mehlich‐1) were not affected by SH, but total C (17%) and N (27%) content increased with taller SH. The soil pool to 20 cm contained approximately 40, 85, 90, and 80% of K, P, N, and C, respectively. Reducing grazing intensity of Tifton 85 bermudagrass pastures appears to be a viable strategy for increasing nutrient content of most plant pools and for increasing the N and C content of the soil pool.