No abstract

Phosphorus (P) supply to crops is a major constraint on the quantity and quality of food production in tropical soils, which are often characterized by highly weathered soils having low phosphorus use efficiency. Increasing P fertilizer use efficiency is a good tool for increasing food production to feed an increasing world population. Enhanced efficiency P fertilizer is used to achieve this goal. The lack of information about soil P diffusive flux and corn and common bean yield response with increased efficiency P fertilizers justify studies to evaluate the performance of this type of fertilizer. The aims of this study were to evaluate P diffusive flux and corn and common bean crop response to P sources and rates. A laboratory trial was carried out to evaluate soil P diffusive flux in response to P sources (MAP and Policote coated MAP). Field trials were carried out to evaluate corn and common bean yields in response to P sources (MAP and Policote coated MAP) and rates. Policote, an additive based on water-soluble polymers, is an anionic copolymer with iron an aluminum affinity. Increasing contact time between P-fertilizers and soil reduced phosphorus diffusive flux. Policote coated P-fertilizer resulted in higher phosphorus diffusion than conventional phosphorus fertilizer. Phosphorus fertilization increased corn and common bean yields. Policote coated phosphorus fertilizer resulted in higher agronomic P efficiency use, corn, and common bean yields than conventional phosphorus fertilizer. Policote coated P fertilizer can be used as an enhanced efficiency fertilizer and is a more efficient way to deliver required phosphorous to plants. Reducing farm investment, increasing agricultural profits, preserve phosphatic rocks reserves, and avoid the overuse of phosphate fertilizer could be realized through the rational use of enhanced efficiency fertilizers and fertilizer rate use reduction.

No abstract

For commercial soybean production, the presence of phosphorus in the soil is essential, not only to increase productivity but also because it affects basic functions in plant metabolism. Phosphate fertilizers have low efficiency in Cerrado soils. For this reason, the use of technologies associated with phosphate fertilizers is important to increase their efficiency in the soil. The experiment was conducted at Fazenda Rio Brilhante in Coromandel, MG. The experiment was laid out in a randomized block design in a 4 × 4 + 1 factorial arrangement. Treatments consisted of four phosphate fertilizer sources (MAPCONVENCIONAL, MAPpol 1, MAPpol 2, and FOM), four P2O5 doses (40, 80, 120, and 160 kg ha-1), and the control treatment (no phosphorus application). The soybean cultivar RK8115 IPRO with a plant population of 340 thousand plants per hectare was used. The experimental plots consisted of five planting lines with a spacing of 0.5 meters and a length of 7 meters. In the experiment, phosphorus leaf, morphological evaluation of plant height, stem diameter, number of stems, and pods were measured. For plant biomass, the dry matter of leaves, stems, and pods were determined. For yield evaluation, the calculation of productivity and RAE was compared with MAPCONVENCIONAL. For sources, data were subjected to analysis of variance, and means were separated by Tukey’s rate test (p < 0.05). For P2O5 doses, regression model fitting was performed using the ExpDes.pt package of R Studio software. Morphological assessments responded linearly to P doses, except for DPM. Leaves and pods P content and yield were affected by P dosage and P sources, with a quadratic response to P dosage. Maximum yield efficiency was achieved at P2O5 doses of 122.73; 145.07; 112.03; and 94.71 kg ha-1, with yields of 3818.30; 4064.67; 4089.03; and 3952.63 kg ha-1 for MAPCONVENCIONAL, MAPpol 2, MAPpol 1, and FOM, respectively. However, MAPpol 1 and FOM provided a dose reduction of 26 and 15 compared to the maximum yield of MAPCONVENCIONAL, respectively.

No abstract