Effects of inorganic and organic amendment on soil chemical properties, enzyme activities, microbial community and soil quality in yellow clayey soil

PLoS One. 2017 Mar 6;12(3):e0172767. doi: 10.1371/journal.pone.0172767. eCollection 2017.

Abstract

Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive rice growing seasons to investigate the effect of applying chemical fertilizer (NPK), NPK plus green manure (NPKG), NPK plus pig manure (NPKM), and NPK plus straw (NPKS) on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC), activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI) and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72) was comparable to that of the NPK (0.77), NPKG (0.81) and NPKS (0.79) treatments but significantly lower compared with NPKM (0.85). The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil.

MeSH terms

  • Agriculture*
  • Biomass
  • Carbon
  • Environment
  • Hydrogen-Ion Concentration
  • Nitrogen
  • Organic Agriculture
  • Soil / chemistry*
  • Soil Microbiology*

Substances

  • Soil
  • Carbon
  • Nitrogen

Grants and funding

Support was provided by The Special Fund for Agro-scientific Research in the Public Interest (201003016), Ministry of Agriculture of the People's Republic of China (WZ received the funding); and the earmarked fund for China Agriculture Research System and the National Basic Research Program of China (2013CB127405), Ministry of Science and Technology of the People's Republic of China (WZ received the funding).