Applications of Humic Acid and Fulvic Acid Under Saline Soil Conditions to Improve Growth and Yield in Barley

Abstract

Abstract Background Enriching the soil with organic matter such as humic acid and fulvic acid to increase its content of available nutrients, improve the chemical properties of the soil and increase plant growth as well as grain yield. Under saline soil conditions a field experiment was carried out for studied the effects of treatment by twelve combinations from adding of humic acid (HA) or fulvic acid (FA) or without adding (control), with four ratios of recommended dose (RDP) of phosphorus fertilizer on some agronomic traits, grain yield, and nutrients uptake in barley, to appraise the beneficial effects of these combinations to improve plant growth, N, P, and K uptake, grain yield, and its components under salinity stress. Results The findings exposed that the treatments HA + 100% RDP (T1), HA + 75% RDP (T2), FA + 100% RDP (T5), HA + 50% RDP (T3), and FA + 75% RDP (T6), improved number of spikes/plant, 1000-grain weight, grain yield/ha, harvest index, the amount of uptake of nitrogen (N), phosphorous (P) and potassium (K) in straw and grain. The increase percentage 64.69, 56.77, 49.83, 49.17, and 44.22% in the first season, and 64.08, 56.63, 49.19, 48.87, and 43.69% in the second season, for grain yield over the control. Meanwhile, the increase was 22.30, 16.42, 11.27, 10.78, and 7.11% in the first season, and 22.17, 16.63, 11.08, 10.84, and 6.99% in the second season, for grain yield compared with the recommended dose. Therefore, it is recommended to treat the soil with humic acid or foliar application the plants with fulvic acid in addition to phosphate fertilizer with one of the following treatments: HA + 100% RDP (T1), HA + 75% RDP (T2), FA + 100% RDP (T5), HA + 50% RDP (T3), and FA + 75% RDP (T6) under salinity conditions. Conclusions The result of the use of organic amendments was an increase in the tolerance of barley plant to salinity stress, which was evident from the improvement in the different traits that occurred after the treatment using treatments that included organic amendments (humic acid or fulvic acid).