Dados do Trabalho

Título

FOLIAR APPLICATION OF CRYSTAL MONOAMMONIUM PHOSPHATE IN SOYBEAN GROWN IN SOIL WITH MEDIUM P CONTENT

Resumo

Phosphorus (P) plays crucial roles in photosynthesis, respiration and energy transfer in plant metabolism. The lower availability of P in highly P-fixing soils is one of the main restrictions on crop production in Brazil. Mitigating this limitation requires the further exploration of alternative methods that improve P use by plants, e.g., foliar spraying. Foliar spraying of P provides direct benefits by increasing the photosynthetic rate and water absorption, which ultimately ensures adequate nutrient uptake by roots. However, the amount of P that can be supplied to crops by foliar spraying is limited by the solution solubility of P, and leaf injury caused by spraying can significantly influence P absorption. Thus, the objective of this work is to evaluate how the soybean crop responds to foliar spraying of monoammonium phosphate crystal (MAP) at different stages, and its effects on nutrition, oxidant and antioxidant metabolism, photosynthetic parameters, agronomic components and grain yield, in a soil with medium P content. The experiments were conducted in randomized blocks, with 4 replicates and six treatments: i - absolute control; ii - MAP in V4; iii - MAP in V6; iv - MAP in R1; v - MAP in and vi - MAP in V4, V6, R1 e R3. Plots were 11 m × 7 rows with 0.45 m spacing between rows. The application of MAP crystal increased the soybean leaf chlorophyll content and RuBisCO activity when sprayed in all phenological stages (complete treatment). MAP crystal application decreased the soybean leaf proline content when sprayed in phenological stage R3.The application of MAP crystal improved the photosynthetic parameters, carboxylation efficiency, and water use efficiency of soybean plants. In this way, the productivity parameters are also improved, with higher grain yields. In general, the application of  monoammonium phosphate helped soybean plants combat periods of stress and increased grain yield.  

Palavras-chave

Foliar supplementation; phosphorus; Glycine max L.

Agradecimentos

OCP Company