Abstract
Andosols are characterized by high organic matter content and play a significant role in carbon storage. However, they have low phosphorus fertility because of the high phosphate-fixing capacity of active aluminum. For agricultural use of Andosols, it is necessary to ameliorate its poor phosphorus fertility by applying lime and high doses of phosphate fertilizers. The objective of the present study was to clarify how such soil amendments affect the mineralization of soil organic carbon (C) and nitrogen (N) in allophanic Andosols under different temperature regimes. The soil was treated using combinations of liming and heavy phosphate application, followed by incubation under different temperature conditions. The N mineralization and the soil CO2 evolution rate were measured periodically. The patterns of N mineralization were analyzed by fitting them to first-order kinetics. Liming increased C and N mineralization irrespective of temperature, and the increase was further enhanced by phosphate application. Kinetic analysis of the N mineralization curve indicated lowering of the activation energy of N mineralization reactions with phosphate application, suggesting that P application may accelerate N mineralization at lower temperatures. These findings provide a basis for developing soil management strategies to reduce the loss of soil organic matter.
Highlights
Accepted: 20 January 2022A huge amount of carbon (C), 1500 Pg C, approximately twice the amount present in the atmosphere and thrice the amount in terrestrial plant biomass, is stored in the soil as organic matter [1]
There was a peak in CO2 evolution at the beginning of the incubation period, followed by a decline and a small peak at ≈40 days, similar to that in the non-liming treat4 of 10 by ment
N mineralization parameters based on the kinetic analysis of N mineralization curves showed that the activation energy, Ea, in the non-liming treatment decreased with an increase in the phosphate application rate (Table 1)
Summary
A huge amount of carbon (C), 1500 Pg C, approximately twice the amount present in the atmosphere and thrice the amount in terrestrial plant biomass, is stored in the soil as organic matter [1]. Any variation in the soil organic matter content significantly impacts the global carbon cycle. The amount of soil C is strongly influenced by environmental factors such as temperature and agricultural management practices such as tillage. Various reports have warned that the increase in decomposition of soil organic matter due to global warming will further accelerate the atmospheric CO2 concentration [3,4,5]. In order to take countermeasures against global warming, it is essential to predict the potential changes in soil C status in response to environmental changes and human activities (such as agricultural soil management practices)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call