Extraction of soil nitrogen by chloroform fumigation – A new index for the evaluation of soil nitrogen supply

• Published in: Soil biology & biochemistry Vol. 43; no. 12; pp. 2423 - 2426
• Main Authors: Yu, Wantai, Brookes, Philip C., Ma, Qiang, Zhou, Hua, Xu, Yonggang, Shen, Shanmin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.12.2011; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Biochemistry and biology; Biological and medical sciences; calcium chloride; Chemical, physicochemical, biochemical and biological properties; chloroform; fumigation; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Lolium; N extracted by chloroform fumigation; N supply; N uptake; nitrogen; nitrogen content; Nitrogen, phosphorus, potassium fertilizations; Physics, chemistry, biochemistry and biology of agricultural and forest soils; potassium chloride; soil; Soil science; Soil-plant relationships. Soil fertility. Fertilization. Amendments; N supply; N extracted by chloroform fumigation; N uptake; Nitrogen fertilization; Soils; Fumigation; Chloroform; Soil science; Nitrogen; Nutrient uptake
• DOI: 10.1016/j.soilbio.2011.07.023
• ISSN: 0038-0717

The N extracted after chloroform (CHCl 3) fumigation was determined as a possible index of soil N supply to plants. The relationships between extractable N following fumigation and reference indices such as total N, alkali-hydrolyzable N, N released by the Stanford short-term incubation method, and the N extracted by KCl and by CaCl 2, were measured in nine soils of differing soil N supply capacity. A highly significant correlation was achieved between the extractable N released by fumigation and the N released by the Stanford method, i.e. a short-term aerobic incubation ( r = 0.87). Similarly, the correlation between extractable N by fumigation and the N uptake by ryegrass was highly statistically significant ( r = 0.93). Using the N extracted following fumigation has the advantage that laboratory results are available in two days and are both reproducible and of high precision. Therefore, the N extracted following fumigation is a valid, timesaving and precise index of soil N supply capacity. ► Significant correlation: N released by Stanford method and CHCl 3 fumigation. ► Significant correlation: extractable N by fumigation and ryegrass N uptake. ► The N extracted following fumigation is a valid index of soil N availability.