Effects of saline water irrigation on rice yield and growth in alluvial soils of red river delta under net-house conditions

Abstract

This study aims to examine the influence of salinity stress on growth, rice grain yield and some
properties of soil under net-house conditions. Experiments were conducted in net houses Vietnam
National University of Agriculture, Gia Lam, Ha Noi during two rice crops from 2/2019 to 10/2019. The
neutral alluvial soil with a salinity of 0.1 ‰ and pHKCl from 5.7 to 6.4 was collected in the Red River
Delta. Saline treatments were 5 concentration points including 1.5; 2; 3; 4; 5 ‰. The control formula
(CF) is irrigated by clean water with 0 ‰ salinity. Each experimental treatment was repeated 3
times/crop. Besides, some soil properties such as EC conductivity, salinity accumulation, pH, available
zinc, plant growth are determined after 20, 40, 60 days. Grain productivity is determined after harvest.
The results show that saline stress seriously affected rice growth and grains. In the 3 ‰ salinity
treatment, the rice yield reduced by 50% and at salinity 4 – 5‰ limited rice growth. For example, the
length of rice leaves was only by 1/3 of CF and rice productivity was only from 0 ÷ 26% of CF). At the
same, stress salt 3 – 5‰ reduces ability zinc nutrient in paddy soil from 3 – 12.88 times.
Keywords: saline water irrigation, salt stress