Factors Affecting Nitrification in Soils

Abstract

Nitrification in soil converts relatively immobile ammonium-nitrogen (N) to highly mobile nitrate-N (via nitrite), and this has implications for N-use efficiency by agricultural systems as well as for environmental quality, especially in situations where the potential for loss of soil or added N is high following nitrate formation. The literature on various physical, environmental, and chemical factors and their interactions on nitrification in soil is reviewed and discussed with examples from natural and agro-ecosystems. Among the various factors, soil matrix, water status, aeration, temperature, and pH have strong influence on nitrification. The information on factors that influence nitrification is useful when developing strategies for regulating nitrification in soils by employing chemical or biological nitrification inhibitors.

Nitrous oxide emission and fertiliser nitrogen efficiency in a tropical sugarcane cropping system applied with different formulations of urea

“…Thus, substantial NO 3 -losses via leaching or denitrification were unlikely during this time. The slow nitrification might be attributable to the ongoing inhibitory effects of low pH (5.06-5.33) in the top 20 cm of soil (Morrill and Dawson 1967;Sahrawat 2008). In the subsequent two months (24 December 2012 to 1 March 2013) when heavy rainfall and the majority of high N 2 O emission episodes occurred, substantial loss of N was most likely to have occurred as a result of leaching or denitrification.…”

Nitrogen deposition and climate effects on soil nitrogen availability: Influences of habitat type and soil characteristics

“…The large-scale spatial pattern of nitrate 445 proportion suggests little influence of soil texture, which varies at a smaller scale. Nitrification has 446 been found in previous studies to be correlated with total N mineralised (Booth et al, 2005) and with 447 soil pH (Andrianarisoa et al, 2009;Sahrawat, 2008; Ste-Marie and Pare, 1999). We also found 448 evidence of correlation between nitrate proportion and both total N rm and soil pH (P < 0.001 for both 449 correlations, in extensively and intensively managed habitats; Table 2 …”

“…The proportion of nitrate in N rm was strongly affected by soil C content and N deposition rate, and 438 was only large in soils with low C content and a large rate of N deposition. Nitrification is affected by 439 aeration (Sahrawat, 2008), and the texture of the soil on fine scales (e.g. clay, silt and sand fractions, 440 or the degree of humification of organic matter) and medium scales (e.g.…”

Challenges in Using Precision Agriculture to Optimize Symbiotic Nitrogen Fixation in Legumes: Progress, Limitations, and Future Improvements Needed in Diagnostic Testing

“…However, the different soil N diagnostic methods currently available are tedious, as they involve soil sample collection, extraction, and multi-step analysis (Table 2) [77]. Also, the concentration of available N in the soil can change rapidly throughout the growing season based on environmental conditions (e.g., soil moisture) [86], therefore monitoring this temporal variability is critical. Fortunately, in situ, on-the-go N determination techniques have been developed based on spectrophotometric/spectroscopic, electrochemical, and biosensor techniques (Table 2) [87,88].…”