Sources and rates of residual phosphorus for Marandu palisadegrass grown in Western São Paulo

Abstract

The pastures of western São Paulo are grown on low fertility soils, therefore, forage has low nutritional value resulting low dry matter yield (DMY).Thus, phosphorus fertilization and analysis of its residual are important for livestock, as it interferes the development speed of forage grasses, allowing better use of area and helping to pasture maintenance, in addition maintaining DMY at adequate levels. This study aimed at evaluating the effect of sources and rates of phosphorus applied in Marandu palisadegrass (Urochloa brizantha cv. Marandu) maintenance to reduce its seasonality, in order to achieve higher yield of these plants. A randomized block design used with 16 treatments and four replications in a 4 x 4 factorial, consisted of four sources of P (Phosphate from Araxá, Reactive phosphate from Arad, Simple superphosphate and thermophosphate) at rates (0, 100, 200 and 300 kg ha -1 of P2O5). A total of ten cuts were performed. DMY was quantified and contents of crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) were determined and P concentrations of Marandu palisadegrass shoot. The residual of sources and P rates did not influence DMY, CP, NDF and ADF contents and P concentrations of plant tissue, indicating that for maintaining Marandu palisadegrass P levels in soil were sufficient and this forage is not demanding regarding this nutrient.Additional keywords: acid detergent fiber; neutral detergent fiber; pasture; phosphorus fertilization; Urochloa brizantha cv. Marandu. ResumoAs pastagens do oeste paulista encontram-se cultivadas em solos de baixa fertilidade, consequentemente, as forrageiras possuem baixo valor nutritivo, acarretando baixa produtividade de matéria seca (PMS). Dessa forma, a adubação fosfatada e a análise de seu residual são importantes para a agropecuária, uma vez que interferem na velocidade de desenvolvimento das gramíneas forrageiras, permitindo melhor rendimento da área e ajudando na manutenção do pasto, além de manter a PMS em níveis adequados. Objetivou-se avaliar o efeito de fontes e doses de fósforo aplicadas na manutenção do capim-marandu (Urochloa brizantha cv. Marandu) para reduzir a estacionalidade do mesmo, visando a maiores produtividades dessas plantas. O delineamento experimental utilizado foi o de blocos ao acaso, com 16 tratamentos e quatro repetições, em esquema fatorial 4 x 4, constituído por quatro fontes de P (Fosfato de Araxá, Fosfato Reativo de Arad, Superfosfato Simples e Termofosfato), nas doses de (0; 100; 200 e 300 kg ha -1 de P2O5). Foram realizados dez cortes do capim-marandu. Quantificou-se a PMS e foram determinados os teores de proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA) e concentrações de P da parte aérea do capim--marandu. O residual de fontes e doses de P não influenciaram a PMS, os teores de PB, FDN e FDA e as concentrações de P do tecido vegetal, indicando que, para a manutenção do capim-marandu, os teores de P no solo foram suficientes e que esta forrageira não é exigente ...

Endophytic PGPB Improves Plant Growth and Quality, and Modulates the Bacterial Community of an Intercropping System

“…NDF and crude protein were determined as described by Silva et al (2009). Nitrogen concentration in shoot tissue (shoot N content) was determined by acid digestion (sulfuric acid) using a semi micro-Kjeldahl distiller Kjeltec TM 8100 (FOSS, Denmark) (Silva et al, 2016).…”

Phosphorus availability in an Oxisol in pastures grown in Southern Brazilian Amazonia

“…One of the major problems is the extremely low levels of available phosphorus as well as the high adsorption capacity of Fe and Al oxides (Silva et al 2016), and require very high P applications to increase production (Fonseca et al, 2020, Grohskopf et al, 2019, Teles et al, 2020. Another relevant factor that the phosphate fertilizers applied to the soils, observes the rates of use of P by the plants are reduced because the adsorption mechanisms (Guedes et al, 2016), mainly in highly weathered soils (Baldotto & Velloso, 2014).…”

Fertilizer application increases nitrate nitrogen concentration in Urochloa brizantha cv. MG5 as annual summer grass in temperate zone

“…Therefore, we hypothesize that the risk of a high nitrate nitrogen concentration at the following cut is higher than that at first cutting because of the combined effects of both basal and additional fertilizer. Silva et al (2016) reported that P fertilizer was found to have no effect to CP concentration in palisadegrass. No effect of P fertilizer on nitrate nitrogen concentration in palisadegrass has been reported.…”