Dinámica de la absorción y partición de nutrientes en Soja

Abstract

Dynamics of nutrient uptake and partition in soybean (Glycine max (L.) Merrill) fertilization requires detailed information for the optimization of nutrient management. Sound economic and environmental nutrient management involves the knowledge of crop nutrient requirements and absorption dynamics during the crop cycle. This study determines soybean requirements and absorption rates of nitrogen, phosphorus, potassium and sulfur; and the effects of fertilization on absorption of nutrients and partition of assimilates and nutrients. A field experiment was conducted on a Typic Argiudoll, which had an available P level of 5 mg kg-1 (Bray 1). Soybean was cropped with and without fertilization (12 kg">12 kg ha-1 of phosphorus). Aboveground biomass and nutrient accumulation and partition to different plant organs were measured during the crop cycle. The maximum absorption rate occurred at different moments for N, K and S than for P. For N, K and S it was at the end of vegetative growth, while for P was at the beginning of seed filling. Potassium was the only nutrient which partition was similar to assimilates. For all other nutrients, the crop partitioned more nutrients than assimilates to leaves, being nitrogen the one that presented the largest difference. Fertilization did not affect assimilates or nutrients partition.