Effect of Soil-Applied L-tryptophan on the Amount of Biomass and Nitrogen and Sulfur Utilization by Maize

Krzysztof Gondek,Monika Mierzwa-Hersztek

doi:10.3390/agronomy11122582

Krzysztof Gondek, Monika Mierzwa-Hersztek

Open Access

https://doi.org/10.3390/agronomy11122582

Copy DOI

Abstract

As natural plant growth stimulators, amino acids are widely used to improve crop yield and quality. There are numerous studies documenting the influence of amino acids on plants, which is not always positive. This study was conducted to determine the effect of soil-applied L-tryptophan (L-TRP) on the accumulation and utilization of nitrogen and sulfur by maize. The study was carried out under the conditions of a pot experiment. The experimental design included three treatments: soil without fertilization (control), soil with mineral fertilization (NPKS), and soil with mineral fertilization and L-tryptophan addition (NPKS + L-TRP). The application of tryptophan to the soil, supported by mineral fertilization, caused a significant increase in maize biomass. Although no significant differences in nitrogen and sulfur contents in maize biomass were found between treatments without and with the addition of L-tryptophan, significantly higher intakes of both elements were observed in the NPKS + L-TRP treatment. The application of L-tryptophan increased the biosynthesis of Chlorophyll a. Utilization of nitrogen and sulfur by maize in the NPKS + L-TRP treatment was more than 27% and 17% higher, respectively, compared to the NPKS treatment. Maintaining the recommended contents of individual nutrients in the rhizosphere is not a guarantee of optimal quantitative and qualitative intake of nutrients. Problems with maintaining optimal relationships between individual nutrients may be compounded by soil properties.

Highlights

Growing problems resulting from deteriorating soil fertility indicators force a search for alternative ways to reduce or eliminate them
The study showed a significant increase in maize biomass in the treatment with soilapplied tryptophan (NPKS + L-TRP) compared to the control and the treatment with only mineral fertilizer (NPKS) (Figure 1)
Problems with maintaining optimal relationships between individual nutrients may be compounded by soil properties

Summary

Introduction

Growing problems resulting from deteriorating soil fertility indicators force a search for alternative ways to reduce or eliminate them. Research has been conducted to introduce new fertilizer formulas or to improve those that are already available by adding various ingredients and substances. That research has been aimed at increasing the effectiveness of fertilizers, and reducing losses of fertilizer components, addressing both the economic aspect and environmental quality issues [1,2]. Given the increasing demands on biomass for food and feed purposes, the importance of biologically active substances, often referred to as biostimulants, is emphasized. According to Regulation (EU) 2019/1009 of the European Parliament and of the Council [3], biostimulants are certain substances, mixtures, and microorganisms that do not provide nutrients but stimulate natural plant nutritional processes. The group of biostimulants can include products containing the so-called beneficial elements (titanium, silicon), products based on algae extracts, and products containing amino acids

Methods

Results

Conclusion