Estimating Potential Nitrogen Mineralisation Using the Solvita Soil Respiration System

Richard L Haney,Elizabeth B Haney

doi:10.4236/ojss.2015.512030

Abstract

Nitrogen (N) mineralisation contributes considerably to crop growth in fertilized and unfertilized fields. It is useful to be able to assess potential N mineralisation to increase fertilizer application efficiency, prevent excessive N runoff, and improve environmental system models. The microbes present in soil mineralize N based on many factors, including soil temperature and moisture, tillage, and levels of organic C and N. The measurement of soil’s ability to mineralize N is considered a good indicator of soil quality. Many methods have been developed to estimate N mineralisation in the laboratory and field. The 7-day anaerobic N mineralisation method developed in the 1960’s is considered reliable and is often used to compare new N-mineralisation testing methods. This study examines the use of soil CO2 evolution as determined using the Solvita Soil Respiration System (Solvita) for estimating N mineralisation by comparing it directly to the anaerobic N mineralisation test. Measured CO2 using Solvita was strongly correlated with anaerobic N mineralisation (r 2 = 0.82). Results indicate that the Solvita Soil Respiration System can be used to rapidly assess soil respiration and relative N mineralisation potential in any given soil and is considerably faster and easier to perform in a laboratory setting than the anaerobic N mineralisation test.

Highlights

Nitrogen (N) and phosphorus inputs are said to be the primary nonpoint sources of pollution in many parts of theHow to cite this paper: Haney, R.L., Haney, E.B., Smith, D.R. and White, M.J. (2015) Estimating Potential Nitrogen Mineralisation Using the Solvita Soil Respiration System
The objective of this study is to apply the Solvita measurement of CO2 in soils to determine N mineralisation and compare it to the 7-day anaerobic N mineralisation method developed by Waring and Bremner [14]
Per kg soil are highly correlated with anaerobic 7-day N mineralisation values (Figure 2). These data correspond with findings by [12], [19] [20] that the flush of CO2 following rewetting dried soil is strongly correlated with potential N mineralisation. While both the anaerobic 7-day mineralisation test and the Solvita test do not require preliminary analysis to determine the amount of water added to each soil, the 7-day N mineralisation test does require preliminary determination and Solvita does not

Summary

Introduction

Nitrogen (N) and phosphorus inputs are said to be the primary nonpoint sources of pollution in many parts of theHow to cite this paper: Haney, R.L., Haney, E.B., Smith, D.R. and White, M.J. (2015) Estimating Potential Nitrogen Mineralisation Using the Solvita Soil Respiration System. Nitrogen (N) and phosphorus inputs are said to be the primary nonpoint sources of pollution in many parts of the. (2015) Estimating Potential Nitrogen Mineralisation Using the Solvita Soil Respiration System. Open Journal of Soil Science, 5, 319-323. Plants obtain N from fertilizer applications, atmospheric deposition, precipitation, and biological fixation and mineralisation. Fertilizer recommendations are routinely based on the amount NO3− determined during soil testing, negating the contribution of N due to biological activity and resulting in over application of fertilizer. Long-term use of fertilizer has a negative environmental impact by contributing to excessive N and P loading in streams, rivers, and the ocean. It is important to be able to accurately predict N mineralisation in the environment; accurate soil N mineralisation estimates are difficult to obtain rapidly in the laboratory setting [2]

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