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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Phosphorus availability and dynamics in soil affected by long-term ruzigrass cover crop
AU - Almeida, D.S.
AU - Menezes-Blackburn, D.
AU - Zhang, H.
AU - Haygarth, P.M.
AU - Rosolem, C.A.
PY - 2019/3/1
Y1 - 2019/3/1
N2 - The use of grasses as cover crops in the off-season of cash crops under no-till has been largely adopted. However, soil phosphorus (P) uptake was previously shown to be reduced when ruzigrass is introduced in the rotation, affecting the viability and sustainability of this cropping system. The objective of this study was to assess the effect of ruzigrass on soil P availability and desorption kinetics under different P fertilizer application rates. A long-term field experiment where soybean (Glycine max) has been grown in rotation with ruzigrass (Urochloa ruziziensis) or fallow for 10 years, with the application of 0, 13, and 26 kg ha−1 of P, was evaluated for two consecutive years. Soil P desorption kinetics was assessed using diffusive equilibrium (DET) and gradient in thin films (DGT) techniques, as well as the DGT-induced fluxes in soils model (DIFS). Microbial biomass P (MBP) was assessed to verify if soil solution P (PDET) was reduced due to immobilization by microorganisms. Ruzigrass reduced MBP and PDET especially when P fertilizer was applied. The concentration of labile P (PDGT) was also lower after ruzigrass than in fallow. The soil ability to resupply P to soil solution was lower after ruzigrass regardless of P rates due to a slower desorption in response to the perturbation imposed by DGT. Growing ruzigrass as cover crop in the soybean off-season decreases soil P availability regardless of P fertilizer application rates by fundamentally reducing P mobility and P resupply from soil solid phase into soil solution. © 2018
AB - The use of grasses as cover crops in the off-season of cash crops under no-till has been largely adopted. However, soil phosphorus (P) uptake was previously shown to be reduced when ruzigrass is introduced in the rotation, affecting the viability and sustainability of this cropping system. The objective of this study was to assess the effect of ruzigrass on soil P availability and desorption kinetics under different P fertilizer application rates. A long-term field experiment where soybean (Glycine max) has been grown in rotation with ruzigrass (Urochloa ruziziensis) or fallow for 10 years, with the application of 0, 13, and 26 kg ha−1 of P, was evaluated for two consecutive years. Soil P desorption kinetics was assessed using diffusive equilibrium (DET) and gradient in thin films (DGT) techniques, as well as the DGT-induced fluxes in soils model (DIFS). Microbial biomass P (MBP) was assessed to verify if soil solution P (PDET) was reduced due to immobilization by microorganisms. Ruzigrass reduced MBP and PDET especially when P fertilizer was applied. The concentration of labile P (PDGT) was also lower after ruzigrass than in fallow. The soil ability to resupply P to soil solution was lower after ruzigrass regardless of P rates due to a slower desorption in response to the perturbation imposed by DGT. Growing ruzigrass as cover crop in the soybean off-season decreases soil P availability regardless of P fertilizer application rates by fundamentally reducing P mobility and P resupply from soil solid phase into soil solution. © 2018
KW - Crop rotation
KW - DET
KW - DGT
KW - Fallow
KW - Urochloa ruziziensis
KW - Amino acids
KW - Cultivation
KW - Desorption
KW - Fertilizers
KW - Nitrogen fixation
KW - Phosphorus
KW - Soil moisture
KW - Desorption kinetics
KW - Diffusive equilibrium
KW - Long-term field experiments
KW - Microbial biomass P
KW - P availabilities
KW - Crops
KW - Glycine max
KW - Poaceae
U2 - 10.1016/j.geoderma.2018.09.056
DO - 10.1016/j.geoderma.2018.09.056
M3 - Journal article
VL - 337
SP - 434
EP - 443
JO - Geoderma
JF - Geoderma
SN - 0016-7061
ER -