ABSTRACT High acidity and low soil P availability in the soils from the Pampa natural grasslands generally limit the forage growth and economic return. Thus, to increase the economic return and avoid environmental degradation and biodiversity loss due to replacement by intensive cropping systems, it is essential to improve the soil P availability. This study aimed to diagnose the nutritional status of the pluri-specific natural grasslands amended with different history of P sources. Additionally, we also try to indicate the […]

Little is known about the agronomic effectiveness of phosphate rocks in high-yielding crop rotation systems under no-till in the Center-South of the state of Paraná, Brazil. This field study was undertaken to compare the effectiveness of rock phosphates and soluble P fertilizers to increase the yield of several annual crops grown in two consecutive triennial crop-rotation cycles under no-tillage. The experiment was carried out in an Oxisol, in Guarapuava, PR, from 2000 until 2006. Two phosphate rocks (PR – Gafsa […]

Soils used for production of flooded rice in the state of Rio Grande do Sul are originated from different parent materials, resulting in different characteristics that affect P availability for the crop. The aim of this paper was to verify the differences in P availability for rice in soils originated from different parent materials. The experiment was carried out in a complete randomized block design, where five soils were exposed to absence or presence of triple superphosphate. In the soils […]

Phosphorus has very low mobility into the soil, but in spite of this, it has been applied on the soil surface on some soil tillage systems. The efficiency of this form of application is not well known yet but can be affected by the soil pH and type of phosphate applied. This study aimed to assess the effect of the application method (mixed into the soil or on the surface, without incorporation) of phosphate fertilizers (diammonium phosphate, triple superphosphate, and […]

Adding simple superphosphate or phosphogypsum to piles of manure or other organic residues has been recommended to reduce losses of ammonia by volatilization during composting. However, experiments have shown discrepant results when the efficiency of these additives and the adequate rate of application are evaluated. This discrepancy could possibly be explained by differences in the residual acidity of the additives utilized in those experiments. To check this hypothesis, a laboratory experiment was carried out using samples of phosphogypsum, simple superphosphate […]

The most commonly studied phosphorus fertilizer placements in maize crop are scattering and furrow  –  localized. However, double furrow intermediary application is also possible, and may increase the fertilized soil fraction and fertilization efficiency. This research was carried out to evaluate the effects of fertilizer placement and doses of phosphorus fertilizer under maintainance fertilization of a corn crop, in a Dark-Red Latosol, in Triângulo Mineiro, Uberaba (MG, Brazil), from October 1995 to April 1996. The treatments consisted of the following […]