Phosphorus fractionation in grasses with different resource-acquisition characteristics in natural grasslands of South America

Abstract

The natural grasslands in South America have soils with low phosphorus (P) availability (1.0 to 7.5 mg kg−1), possibly altering the absorption and accumulation of P in grasses. We evaluated the chemical fractionation of P in the leaves of the most important grasses present in these grasslands to better understand the mechanisms involved in the storage of P. The grasses studied were Axonopus affinis and Paspalum notatum (fast tissue cycling and high nutrient demand) and Andropogon lateralis and Aristida laevis (slow tissue cycling and low nutrient demand). They were grown in pots filled with an Ultisol with two levels of P: control, and addition of 50 mg P kg–1. The main P fractions were the inorganic soluble (44%) and P in RNA (26%). Addition of P increased the total P concentration, following the order A. affinis (140%) > P. notatum (116%) > A. lateralis (81%) > A. laevis (21%). In conclusion, the species A. affinis and P. notatum responded to P fertilization with high variation and accumulating P in less-structural chemical forms, such as inorganic P. The species A. lateralis and A. laevis showed low variation in the concentration of P forms, with higher P concentrations in structural forms.

Phosphate fertilization and liming in a trial conducted over 21 years: A survey for greater forage production and Pampa pasture conservation

“…Vegetation growing in these soils comprises species adapted to local conditions such as low P availability and soil acidity (Oliveira et al, 2018;Marques et al, 2019). Approximately 3,000 plant species can be found in the Pampa grassland ecosystem (Pampa biome), 450 of them are grass species used for forage production (Boldrini, 2009).…”

Interaction between growth strategies and phosphorus use efficiency in grasses from South America natural grasslands

“…Phosphorus (P) is a macronutrient that often limits plant growth worldwide (Van de Wiel et al, 2016). It is a nutrient with great importance in the transfer of metabolic energy, photosynthesis and respiration, as well as a component of nucleotides, phospholipids and phosphorylated sugars (Elanchezhian et al, 2015;Marques et al, 2019). However, in most soils, especially under tropical grasslands conditions, P is low available to the plants.…”