Response of Arbuscular Mycorrhizal Fungi and Soil Chemical Properties to Brachiaria decumbens Grass Production Technologies

HIGHLIGHTS

• Brachiaria decumbens pasture associated with kudzu Pueraria phaseloides legume represents an alternative for higher arbuscular mycorrhizal fungi (AMF).

• Higher lime doses presented high rates of AMF and improved soil chemical properties (SCP).

• Higher lime doses were the most influential technological factor than the type of pasture and the N, P, K fertilizer sources on AMF.

Abstract

In order to improve the sustainability of livestock systems at Cumaral, Meta, under tropical conditions of Colombia, implementation of different Brachiaria decumbens production technologies can be beneficial for a better soil fertility. This study aimed to evaluate the effects of two pastures type (Factor A): (a) Brachiaria decumbens grass (B1) and Brachiaria decumbens grass associated with kudzu Pueraria phaseloides legume (B2); (b) Factor B: Four lime (CaCO₃) doses: L0 = 0 tons ha^-1, L1 = 1.1 tons ha^-1, L2 = 2.2 tons ha^-1 and L3 = 3.3 tons ha^-1; and (c) Factor C: three N, P, K fertilizers sources: 100 kg ha^-1 Urea, 200 kg ha^-1 triple superphosphate (TSP) and 100 kg ha^-1 potassium chloride (PCl) on arbuscular mycorrhizal fungi (AMF) and soil chemical properties (SCP). Cluster analysis showed that B2*L3, L2*Urea, TSP, PCl increased the number of AMF spores per g soil and improved soil chemical properties (SCP), as B1*L3*Urea, TSP, PCl, in cluster 1, higher lime doses were the most influential factor, indistinctly pasture type, as N, P, K fertilizer sources showed low effect in cluster conformation. Farmers in the area can implement these B. decumbens technological practices that help improve the sustainability of livestock systems at tropical zones.

Keywords:
fertilizers; lime; soil fertility; soil biology; technology