Vector diagnosis of nutrient dynamics in mesquite seedlings

Abstract

This paper reports an application of vector analysis to interpret temporal interrelationships between plant biomass and nutrient status with time, as demonstrated using young mesquite (Prosopis chilensis) seedlings. Conventional (single dose or constant top dressing), and exponential (pure or modified exponential) fertilization schedules were used to induce contrasting plant nutrient status in the seedlings over a 12 wk growing season. Progressions in nutrient status showed that conventional fertilization resulted in nutrient dilution whereas pure exponential fertilization achieved steady-state nutrient conditions after an initial deficiency. The modified exponential schedule attained steady-state nutrition for most of the experimental period. These trends were similar for all the three elements (N, P, and K). This study demonstrated that dynamic time dependent responses such as steady-state nutrient conditions, nutrient dilution, and accumulation can be identified using traditional vector analysis provided a fourth variable, time (t), is introduced. This approach also allows simultaneous comparisons of multiple elements on the same nomogram, facilitating assessment of differential nutrient absorption during seedling development.