Effect of lignosulfonate application to sandy soil on plant nutrition and physiological traits

Abstract

The application of nutrient-rich substrates to soils characterized by low natural fertility is discussed as a strategy to improve soil fertility and, consequently, affect plant physiological traits. This study aimed to evaluate if sodium lignosulfonate (LS), a by-products of pulp and paper industry, may improve plant ecophysiological traits under contrasting nutrient conditions. A pot culture experiment was conducted with cucumber plants, using LS concentrations of 0, 1, 2.5, 5, and 10 vol.% in sandy soil, and two soil nutrient levels: sufficient and low nutrient availability (SNA and LNA, accordingly). The LS increased N and P content in SNA leaves when 1% of LS was used and decreased N content in LNA leaves regardless of soil LS content. The LS did reduce mass-, N-, and P-based respiration rates of the SNA leaves, and increased the N-based respiration rate under LNA. The LS did not have a significant impact on the ratio of respiration to photosynthesis in SNA leaves, but decreased it under LNA. The LS application contributed to a slight activation of some physiological processes in LNA plants, but it was not successful to recover these activities to the level of plants grown under SNA.