Phosphorus sources enriched with filter cake and microorganisms in the soil microbiota: Phosphorus absorption and sugar cane dry matter production

ABSTRACT Phosphate fertilization has increased sorghum yield, but few studies are available on sorghum production and efficient fertilizer management related to liming and phosphorus (P) sources. This work evaluates production, dry matter partitioning and agronomic efficiency (AEI) in successive sorghum cycles after application of limestone and combinations of phosphorus sources. Two cycles were conducted in sequence in the same experimental field, in a 2 x 6 factorial scheme, corresponding to soil with or without liming and six combinations of P2O5 sources: control (0 kg ha-1 P2O5), 100% Itafós natural phosphate (NP), 75% NP + 25% single superphosphate (SS), 50% NP + 50% SS, 25% NP + 75% SS and 100% SS. Pots with capacity for 8 dm3 were used in a randomized block design with four replicates. The first cycle, conducted in the summer/autumn season, reached the highest dry matter production and P accumulation in treatments with higher SS proportions, leading to higher AEI. Subsequently, in the second cycle, conducted considering only the residual phosphate fertilization of the first cycle, highest dry matter production and AEI were obtained in the treatment with 100% or higher proportions of natural phosphate in the presence of liming, most likely due to the gradual release of P.

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Evaluation of perennial herbaceous legumes with different phosphorus sources and levels in a Brazilian Ultisol

Renewable Agriculture and Food Systems ◽

10.1079/raf200492 ◽

2005 ◽

Vol 20 (1) ◽

pp. 56-62 ◽

Cited By ~ 5

Author(s):

J.A.A. Espindola ◽

J.G.M. Guerra ◽

D.L. Almeida ◽

M.G. Teixeira ◽

S. Urquiaga

Keyword(s):

Cover Crops ◽

Dry Matter ◽

Soil Layer ◽

Soil Surface ◽

Dry Matter Production ◽

Organic C ◽

Herbaceous Legumes ◽

Matter Production ◽

Phosphorus Sources ◽

Phosphate Fertilization

AbstractThis study was carried out under field conditions with the aim of evaluating the period of time necessary for soil cover, dry matter production and accumulation of nutrients by perennial herbaceous legumes with different phosphorus sources at different levels. Four legumes were evaluated: calopo (Calopogonium mucunoides Desv.), forage groundnut (Arachis pintoi Krap. & Greg.), siratro (Macroptilium atropurpureum (OC.) Urb.) and tropical kudzu (Pueraria phaseoloides (Roxb.) Benth.). Each of these species received different phosphorus (P) sources and levels: no phosphate fertilization; 44 and 88 kg of P ha−1 applied as rock phosphate; and 44 kg of P ha−1 as triple superphosphate. Calopo, siratro and tropical kudzu completely covered the soil surface 129 days before forage groundnut. Phosphate fertilization did not increase the dry matter production of any species. The legumes forage groundnut, siratro and tropical kudzu showed desirable characteristics that promote their use as cover crops, such as high dry matter production and shoot accumulation of nitrogen (N) and potassium (K). Forage groundnut had the highest proportion of N derived from the atmosphere at the end of the rainy season, while there were no significant differences between the legumes at the end of the dry season. There was an elevation of soil pH and calcium+magnesium (Ca+Mg) contents, associated with a reduction of aluminum (Al) content, in the surface soil layer (0–5 cm) for siratro in relation to groundnut and tropical kudzu. Tropical kudzu promoted higher soil organic C contents when compared to groundnut.

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