Organic material combined with beneficial bacteria improves soil fertility and corn seedling growth in coastal saline soils

ABSTRACT Soil salinity is a major abiotic stress on plant growth in coastal saline soil. The objective of this study was to screen the optimal combination of organic materials with beneficial bacteria for application under real field conditions to improve coastal saline soil. A two-factor pot experiment was carried out with corn in coastal saline soil for 26 days. In the naturally aerobic environment, a split-plot experiment was conducted with different rates of organic materials (organic fertilizer and mushroom residue) and beneficial bacteria (phosphate - and potassium-solubilizing bacteria). The 10 treatments consisted of a control (inactivated bacteria cells and no organic material), and combinations of organic materials (2, 4, and 6 % of the total soil dry weight), respectively, with beneficial bacteria [at 1 × 108, 2 × 108, and 3 × 108 colony-forming units (cfu) plant-1]. The application of 6 % organic material and beneficial bacteria at 3 × 108 cfu plant-1 (F6B3) promoted the highest seedling height, stem diameter, and dry biomass of corn seedlings, which increased by 0.30~26.78 %, 8.70~27.23 %, and 22.13~156.90 %, respectively, compared with the other FB (organic fertilizers and beneficial bacteria) treatments. Compared with all other FB treatments, soil total nitrogen, available phosphorus, and available potassium were increased by 4.78~18.04 %, 8.99~25.59 %, and 0.96~36.25 %, respectively, in F6B3. This treatment decreased soil total salt content by 0.79~12.72 %, compared with the other FB treatments. Based on the comprehensive improvement scores, F6B3 was identified as the best treatment for coastal saline soil. Organic materials combined with beneficial bacteria could improve nutrient availability and reduce salinity of coastal saline soil and promote corn seedling growth. The combined application of 6 % of organic materials with 3×108 cfu plant-1 of beneficial bacteria proved the most effective for coastal saline soil, and is recommended for field application.