Impacts of Soil Amendments and Fertilization Strategies on the Functions of Agroecosystems : with special attention to coastal saline soils

In this dissertation, the effects of fertilization and amendments on soil properties and crop yield are studied by field and incubation experiments as well as statistical approaches such as meta-analysis. Our results show that higher soil salinity levels lead to lower soil hydrolysis and nitrification rates; meanwhile the inhibitory effect of Cl on nitrification is stronger than that of SO42– under similar soil salinity levels. In addition, organic amendments (e.g., compost, crop residue, and sewage sludge) can directly replenish soil elemental pools (C, N, and P) and increase crop yield. Soil amendments facilitate soil salt leaching by improving soil structure; however, they may introduce certain amounts of salts and contaminants depending on the source of the raw materials. The combined application of inorganic and organic amendments may be more beneficial than the single application of amendment however the budget increases accordingly. Therefore, the application type and amount of amendments should be assessed to minimize the potential adverse effects and financial costs. Furthermore, increased soil salinity levels may break bigger soil aggregates into smaller ones and thus reduce soil aggregate stability, depending on the magnitude of soil salinization. In terms of SOC turnover, balanced fertilization (NP and NPK) generally enhances the sequestration rate of soil C pools (SOC; microbial biomass carbon, MBC; and dissolved organic carbon, DOC) and the increase rate of crop yield compared to the single N fertilization. The effect of balanced fertilization on SOC is affected by straw return, whereas other agricultural management practices, including crop rotation systems, crop types, tillage strategies, and filming mulching, show no obvious impact on SOC. These results indicate that balanced fertilization promotes SOC sequestration but it may cause soil acidification in the meantime.

Rights

Use and reproduction:

No license. The provisions of the German Copyright Act (UrhG) apply.

Please note that individual components of the publication may be subject to other licensing or copyright conditions.

Cite

Citation style:
Tao, J., 2024. Impacts of Soil Amendments and Fertilization Strategies on the Functions of Agroecosystems: with special attention to coastal saline soils.
Could not load citation form.