Role of the bacteria and humic acids in soil element availability and barley growth
Abstract
ustainable agricultural development is an ideal solution to address the global food shortages especially in Iraq. This is due to the pollution of agricultural areas and the lack of water resulting from the use of excessive mineral fertilizers which have led to a decrease in the productivity of plants. An experiment was conducted at the research station of the Directorate of Agricultural Research of the Iraqi Ministry of Agriculture to determine the effect of plant growth-promoting rhizobacteria. For plant growth, PGPR interacts with humic acid sprayed in nutrient plots and mixed into the soil in barley growth, and the preparation of nitrogen and phosphorus in the soil. The experiment was carried out in a factorial design (RCBD). The results show that the addition of PGPR bacteria is superior (in terms of nitrogen and preformed phosphorus in the soil, plant height, leaf area, number of branches, weight per 1000 grains, and grain yield),resulting in (32.35 mg kg -1 , 22.15 mg kg -1 , 63.96 cm, and 14.50 cm 2 of plants, 6.73 plant shoots -1 , 32.60 grains, and 2.99 Mg ha -1 , respectively). The interaction of plant growth promoting bacteria with humic acid also showed significant dominance, with the nutrient treatments amended with bacteria being superior in terms of soil nitrogen and phosphorus contents, plant height, leaf area, branch number, seed weight per 1000 kernels, and grain yield (37.00 mg kg -1 , 24.07 mg kg -1 , 66.76 cm, 16.57cm 2 plant -1 , 7.32 shoots plant -1 , 35.41 grains and 3.32 Mg ha -1 , respectively).