Aftereffect of Seven Years of Straw Handling on Soil Sustainability and Vitality

Straw, as organic material, contains macronutrients and a wide range of micronutrients. Properly treated straw can become a valuable source for soil improvement and crop nutrition needs. The field experiment was carried out at the Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry, in 2014–2021 on Cambisol. On a shallow ploughless tillage background, eight treatments were investigated: chopped straw + ammonium nitrate (CSA), chopped straw + ammonium nitrate + NPK (CSA+F), chopped straw + microorganisms (CSM), chopped straw + microorganisms + NPK (CSM+F), straw removed, not fertilized (SR), straw removed, fertilized (SR+F), chopped straw, not fertilized (CS), chopped straw, fertilized (CS+F). We hypothesized that treatment of straw with microbiological products in combination with mineral NPK fertilizers is a more efficient technology than treatment/non-treatment of straw with ammonium nitrate, either with or without NPK fertilizers. The aim of this work was to investigate the aftereffects of seven years use of mineral NPK fertilizers and bioproducts containing soil bacteria and microscopic fungi (Bacillus megaterium, Acinetobacter calcoaceticus, and Trichoderma reesei) in combination with straw management on soil sustainability (soil C sources, soil water release characteristics, pore-size distribution, aggregate stability, crop yielding capability) and soil vitality (CO2 exchange rate-NCER). It was revealed that NCER was highest in the treatment CSM+F (Bacillus megaterium, Acinetobacter calcoaceticus, and Trichoderma reesei + NPK). It was 32.95% higher than in CSA (chopped straw without fertilizers) and 45.34% higher than in CSA+F (chopped straw + ammonium nitrate + NPK). Bioproducts applied favored soil vitality in general by exhibiting higher soil microbiological activity. As a result, a healthy and more viable Cambisol produced a higher winter wheat grain yield.