Short Term Effects of Revegetation on Labile Carbon and Available Nutrients of Sodic Soils in Northeast China

Pujia Yu,Wenxin Liu,Xuguang Tang,Shiwei Liu,Aichun Zhang

doi:10.3390/land9010010

Abstract

In response to land degradation and the decline of farmers’ income, some low quality croplands were converted to forage or grassland in Northeast China. However, it is unclear how such land use conversions influence soil nutrients. The primary objective of this study was to investigate the influences of short term conversion of cropland to alfalfa forage, monoculture Leymus chinensis grassland, monoculture Leymus chinensis grassland for hay, and successional regrowth grassland on the labile carbon and available nutrients of saline sodic soils in northeastern China. Soil labile oxidizable carbon and three soil available nutrients (available nitrogen, available phosphorus, and available potassium) were determined at the 0–50 cm depth in the five land uses. Results showed that the treatments of alfalfa forage, monoculture grassland, monoculture grassland for hay, and successional regrowth grassland increased the soil labile oxidizable carbon contents (by 32%, 28%, 15%, and 32%, respectively) and decreased the available nitrogen contents (by 15%, 19%, 34%, and 27%, respectively) in the 0–50 cm depth compared with cropland, while the differences in the contents of available phosphorus and available potassium were less pronounced. No significant differences in stratification ratios of soil labile carbon and available nutrients, the geometric means of soil labile carbon and available nutrients, and the sum scores of soil labile carbon and available nutrients were observed among the five land use treatments except the stratification ratio of 0–10/20–30 cm for available phosphorus and the values of the sum scores of soil labile carbon and available nutrients in the 0–10 cm depth. These findings suggest that short term conversions of cropland to revegetation have limited influences on the soil labile carbon and available nutrients of sodic soils in northeastern China.

Highlights

The structure, diversity, and production capacity of terrestrial ecosystems are strongly linked to the availability of soil nutrients, such as nitrogen, phosphorus, potassium, and soil organic carbon [1,2].the soil labile carbon and soil nutrients’ availability in terrestrial ecosystems are usually influenced by various direct and indirect soil disturbances [3,4]
The was conducted in the Songnen plain located at the Grassland Farming and Ecological Research
Soil pH was not affected by the land use conversions

Summary

Introduction

The structure, diversity, and production capacity of terrestrial ecosystems are strongly linked to the availability of soil nutrients, such as nitrogen, phosphorus, potassium, and soil organic carbon [1,2].the soil labile carbon and soil nutrients’ availability in terrestrial ecosystems are usually influenced by various direct and indirect soil disturbances [3,4]. One main mechanism by which they do this is by changing the quantity and quality of plant biomass supplied to the soils, affecting the rate of organic matter decomposition and the activity of soil microorganism and redistributing soil carbon and nutrients within soil profiles [7,8,9]. Another main mechanism is the impact of soil erosion, which preferentially removes the surficial and most carbon and nutrient rich material, accelerating the decline of the soil organic carbon and soil nutrient pool [10,11]. Changes of soil organic carbon (soil microbial biomass carbon, particulate organic carbon, water extractable organic carbon, etc.) and total nutrients (total nitrogen, total phosphorus, total potassium, etc.) under different land uses in different spatial and temporal scales induced by long term land use conversions have been well addressed [13,14,15,16,17]

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Conclusion