Sorghum yield after liming and combinations of phosphorus sources

Abstract

A B S T R A C TPhosphate 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 P 2 O 5 sources: control (0 kg ha -1 P 2 O 5 ), 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 dm 3 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.Produção de sorgo cultivado após aplicação de calcário e combinação de diferentes fontes de fósforo R E S U M OA adubação fosfatada tem propiciado aumentos na produção de sorgo, mas são escassos estudos relacionados ao uso de fontes de fósforo e calcário na sua produção e uso eficiente da adubação. Neste sentido, objetivou-se avaliar a produção e partição de matéria seca, e a eficiência agronômica em cultivos sucessivos de sorgo após combinações com fontes de fósforo e calcário. Para tanto, foram conduzidos dois cultivos em sequência, no esquema fatorial 2 x 6, com duas doses de calcário (com e sem calcário) e seis combinações com fonte de P 2 O 5 : testemunha (0 kg ha -1 de P 2 O 5 ), 100% de fosfato natural Itafós (NP), 75% NP + 25% de superfosfato simples (SS), 50% NP + 50% SS, 25% NP+ 75% SS e 100% SS. Utilizou-se o delineamento em blocos casualizados com quatro repetições e os cultivos foram conduzidos em vasos de 8 dm 3 . No primeiro cultivo, conduzido no período de verão/ outono obteve-se maiores produções de matéria seca e acúmulo de P nos tratamentos com maiores proporções de SS, implicando na obtenção de maior índice de eficiência agronômica (IEA). No segundo cultivo, realizado logo após, e considerando somente a adubação fosfatada residual do primeiro, maiores produções de matéria seca e IEA foram observados no tratamento com o uso integral ou maiores proporções de fosfato natural, na presença de calcário, possivelmente em decorrência da liberação gradual de fósforo.

Potential screening of photoremediating crops and performance of maize in photoremediated coal mined acid soil with phosphorus application

“…Graded application of phosphorus fertilizer significantly and markedly increased the mean dry matter yield of maize planted in sunflower and asparagus bean remediated soils as compared to maize grown in non-phytoremediated soil or control. Similar results was reported by Ahmed (2017) and Silveira et al, (2018), Getnet and Dugasa, (2019) for Faba beans, sorghum and maize. The dry matter yield of maize grown in Asparagus bean and sunflower remediated soils, as evident in Table 4, increased significantly with increasing levels of phosphorus up to 90 mg P kg 1 soil, respectively.…”

Agronomic efficiency of organomineral fertilizer in sequential grain crops in southern Brazil

“…Agronomic Efficiency Index (AEI) of fertilizers was calculated based on the grain yields of the crops, using Equation 2 (Silveira, Pegoraro, Kondo, Portugal, & Resende, 2018):…”

“…The yield in the treatments OM 100, PL 100, MF 100, MF 150, and OM 150 were 84, 68, 77, 83, and 87% higher than the control, respectively. Higher SDMY may be due to fertilization (Silveira et al, 2018) and commonly has a positive correlation with grain yield. Moreover, the largest input of vegetal biomass contributes to the stabilization and/or increase in the content of soil organic matter (SOM; Antille et al, 2017), which increases soil quality (Borges et al, 2019;Fontoura et al, 2019).…”

“…1)Agronomic Efficiency Index (AEI) of fertilizers was calculated based on the grain yields of the crops, using Equation 2(Silveira, Pegoraro, Kondo, Portugal, & Resende, 2018): AEI (%) = (treatment yield − control yield) (MF100yield −control yield) 100 (2) Use efficiency (UE) of the applied P (PUE), K (KUE), and N (NUE) from fertilizers were calculated based on grain yield of the crops, using the equation proposed by Syers et al (2008): UE ( kgkg −1 ) = treatment yield − control yield total amount of nutrient used (N, P, or K) (3) Moreover, physiological efficiency (PE) was calculated to relate grain yield to the amount of nutrient accumulated in the shoot of the plants. PE was calculated for the amount of P (PPE), K (KPE), and N (NPE) accumulated in the plant, using Equation 4, proposed by Restelatto, Pavinato, Sartor, Einsfeld, and Baldicera (2014): PE ( kgkg −1 ) = treatment yield −control yield cumulative nutrient SDMYtreatment − cumulative nutrient SDMY control (4)…”

Long‐term phosphate fertilization strategies evaluation in a Brazilian Oxisol

“…Natural phosphates with medium solubility in citric acid, such as reactive rock phosphates (RRP), usually represent a small market‐share although the P unit cost is less than that of soluble fertilizers. In addition, these sources present even greater residual effect in soil due to its slower solubilization (Oliveira et al., 2019; Silveira, Pegoraro, Kondo, Portugal, & Resende, 2018). On the other hand, highly soluble sources are able to rapidly release P to plants after dissolution in soil solution, but may have the adverse effect of prompting exposure of P to adsorption sites.…”