Growth characteristics of Suaeda salsa under different soil salinity gradients in controlled experiments

Fei Zhang,Ligang Ma,Yun Chen,Jie Yuan,Changjiang Liu

doi:10.25165/j.ijabe.20211405.5871

Abstract

Xinjiang is the province with the largest saline-alkali land in China. The growth of halophytes will be stressed when their salt content reaches the threshold. In this study, the pot experiments were conducted and Suaeda salsa, a typical halophyte, was selected as the object to explore the relationship between growth characteristics and salt content under different soil salinity gradients. Salinity gradients were set according to the maximum soil salinity in the current years of Ebinur Lake Wetland National Nature Reserve (ELWNNR). They were classified using the following threshold values: ≤2 g/kg (Control Group), 10 g/kg, 20 g/kg, 30 g/kg, and 40 g/kg. The original spectrum, trilateral position and growth characteristics were used as indexes for analysis. With the increase of soil salt content, the red edge shift occurs first, followed by the blue edge shift. The position of yellow edge, green peak and blue edge were not sensitive with the change of soil salinity. This indicates that the red edge is the best indicator for evaluating plant growth. Compared with the Control Group, when the salt content is less than 10 g/kg, the growth status of plant seems not significantly affected. However, plant growth begins to be stressed when the salt content increases to 20 g/kg, which is a turning point for plant health. The increase of soil salt content can inhibit chlorophyll synthesis and plant growth. Plants begin to die when the salt content reaches the 40 g/kg. Therefore, 40 g/kg could be regarded as the critical point of salt content which inhibits plant growth. The study also shows that the relationship between plant-height change rate and soil salt content is the most significant, indicating that the plant-height change rate is significantly impacted by soil salt content. Keywords: Suaeda salsa, soil salt content, gradient, spectral, growth characteristics DOI: 10.25165/j.ijabe.20211405.5871 Citation: Zhang F, Chen Y, Yuan J, Ma L G, Liu C J. Growth characteristics of Suaeda salsa under different soil salinity gradients in controlled experiments. Int J Agric & Biol Eng, 2021; 14(5): 142–148.

Highlights

Salinity is one of the major factors that affect plant growth and metabolism, leading to severe damage and a loss of productivity, approximately 20% (45 million hm2) of irrigated land is salt-affected[1]
3.1 Original spectral curves under different salinity gradients There was much noise in the water absorption bands for the spectral curves of wild plants, such as 1353-1409 nm, 1801-1940 nm, and 2401-2500 nm, the spectral noise was deleted in this paper
The positions of yellow edge, green peak and blue edge are not sensitive with the change of soil salt content, so, in subsequent analysis, only the red edge position is taken as the response index to study

Summary

Introduction

Salinity is one of the major factors that affect plant growth and metabolism, leading to severe damage and a loss of productivity, approximately 20% (45 million hm2) of irrigated land is salt-affected[1]. Salt stress, caused by either saline or sodic soils, represents a major threat to global food production, with estimates of up to $30 billion in agricultural losses annually. Xinjiang is the largest arid region in China, with a total area of approximately 1.66×106 km. Xinjiang is the largest arid region in China, with a total area of approximately 1.66×106 km2 It belongs to a typical continental arid climate. The saline and alkaline soil areas reach 8.48×104 km, and 31.1% of the arable farmland is salt-affected[10,11]. Suaeda salsa is an annual mesophyll herb of Chenopodiaceae, the main halophytes in saline-alkali soil of China[12]

Methods

Results

Conclusion