Changes of Soil Nutrients and Enzyme Activities in Calcareous Purple Soil Under Long-term Continuous Cropping for Tobacco Planting

Abstract

【Objective】The problem of soil nutrient imbalance becomes more and more serious with the increase of tobacco planting years. The effects of continuous cropping of flue-cured tobacco on soil nutrients and enzyme activities in calcareous purple soil were systematically studied to provide data support for the improvement of soil fertility and the prevention and control of continuous cropping obstacles.【Method】In April 2021, typical plots of calcareous purple soil with different continuous cropping years (0 year, and 8, 10, 27, 33 years) in Zhaohua District, Guangyuan City were selected as the research objects, and the effects of long-term continuous cropping on soil nutrients, enzyme activities and the growth and development of flue-cured tobacco were analyzed.【Result】Long-term continuous cropping of flue-cured tobacco led to the decrease of soil organic matter, pH and alkaline nitrogen by 18.34%, 17.43% and 23.15%, while the contents of soil available phosphorus and available potassium increased by 124% and 54.55%, respectively. Long-term continuous cropping resulted in a decrease of 58.51%-91.28% in urease activity and a decrease of 29.14%-48.66% in sucrase activity in soil. The results of correlation analysis showed that soil sucrase activity was significantly negatively correlated with soil available phosphorus (P < 0.01). Soil β-glucosidase was significantly positively correlated with soil available potassium content (P < 0.01), while significantly negatively correlated with soil available phosphorus (P < 0.05). The soil urease activity was significantly positively correlated with soil pH (P < 0.01).【Conclusion】Long-term continuous cropping of flue-cured tobacco in calcareous purple soil has an inhibitory effect on soil nutrients and enzyme activities. Attention should be paid to the balanced application of nitrogen, phosphorus and potassium fertilizers, and organic fertilizer can be appropriately added to regulate the soil microenvironment to promote the transformation and absorption of nutrients.

Keywords

• flue-cured tobacco
• purple soil
• continuous cropping obstacle
• nutrient imbalance
• enzyme activity
• arable land quality