Assessment of natural mycorrhizal colonization and soil fertility status of lemongrass [(Cymbopogon flexuosus, Nees ex Steud) W. Watson] crop in subtropical India

- Lemongrass grown as aromatic plants worldwide.
- Significant naturally mycorrhizal root colonization was noticed.
- Decreased the soil pH and enhanced soil organic carbon content.
- Improved soil enzymes and available soil nutrients status.

The objective of this experiment was to evaluate the changes on mycorrhizal root colonization (through natural infection into the lemongrass roots), soil pH, soil organic carbon (SOC), total nitrogen, available soil nutrients and soil enzymes of lemongrass in plant crop (1st year) and their subsequent crops [2nd year (1st ratoon) and 3rd year (2nd ratoon)]. The results showed that chemical and biological properties of the soil was significantly influenced by plant crop (1st year) and subsequent ratoon crops (2nd and 3rd year). Natural mycorrhizal root colonization was significantly observed in lemongrass crop. Maximum mycorrhizal root colonization (74%) was found in the 3rd year lemongrass crop. Soil pH significantly decreased in the 2nd and 3rd year crops as compared to the fallow soil. The maximum SOC (58%), total nitrogen (65%), available P (204%) and available K (52.9%) was build up in the 3rd year crop soil as compared to the fallow soil. Among all the crop years (1st year, 2nd year and 3rd year) NH4+-N had higher concentration compared to NO3−-N in lemongrass grown soil as well as fallow soil. The soil enzymes activity in lemongrass field was significantly higher as compared to fallow soil.

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