Please cite this article in press as: Marchetti, R., et al., Nitrogen and carbon mineralization in soils amended with biofumigant or non-biofumigant plant materials. Ind. Crops Prod. (2015), http://dx.doi.org/10.1016/j.indcrop.2015.04.062 ARTICLE IN PRESS G Model INDCRO-8048; No. of Pages 8 Industrial Crops and Products xxx (2015) xxx–xxx Contents lists available at ScienceDirect Industrial Crops and Products journal homepage: www.elsevier.com/locate/indcrop Nitrogen and carbon mineralization in soils amended with biofumigant or non-biofumigant plant materials Rosa Marchetti a,∗ , Luca Lazzeri b , Lorenzo D’Avino c , Gilda Ponzoni a a Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria, Unità di ricerca per la suinicoltura (CRA-SUI), Via Beccastecca 345, 41018 San Cesario sul Panaro, Modena, Italy, b Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria, Centro di ricerca per le colture industriali (CRA-CIN), Via di Corticella, 133, 40128, Bologna, Italy c Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria, Centro di ricerca per l’agrobiologia e la pedologia (CRA-ABP), via di Lanciola 12/A, 50125 Cascine del Riccio, Firenze, Italy a r t i c l e i n f o Article history: Received 2 July 2014 Received in revised form 28 February 2015 Accepted 28 April 2015 Available online xxx Keywords: Brassicaceae Defatted seed meals Green manure Nitrogen mineralization Carbon mineralization a b s t r a c t Biofumigant plant materials from Brassicaceae are rich in nutrients and could represent an interest- ing source of organic nitrogen for crops, when used as soil amendments. In this study, we evaluated in two laboratory experiments the nitrogen and carbon mineralization in soil amended with glucosinolate- containing (Brassica carinata defatted seed meals and Brassica juncea green manure) or non-containing (carinata crop residues, and sunflower) plant materials. In the first experiment, two soils of contrasting texture (a loam and a silty clay) were amended with carinata defatted seed meals, B. juncea green manure, carinata crop residues and un-amended control. In the second experiment, a loam soil amended with car- inata and sunflower defatted seed meals obtained by mechanical and solvent extraction were compared. The amount of mineralized nitrogen at the end of a 3-month incubation period was on average 56.6% of the added nitrogen in soil amended with carinata seed meals, and 39% in soil amended with B. juncea green manure, whereas nitrogen immobilization occurred in soil amended with carinata crop residues. Inorganic nitrogen release was faster in soil amended with carinata defatted seed meals. These results were related to carbon to nitrogen ratio in the plant materials. The soil type did not affect N mineral- ization of the amendments. No negative effect on mineralization could be attributed to the presence of glucosinolates or to the oil extraction method. Biofumigant defatted seed meals from carinata, used as soil amendments, release interesting inorganic-nitrogen amounts into soil and could therefore substitute chemical nitrogen fertilizers for crop nutrition. © 2015 Elsevier B.V. All rights reserved. 1. Introduction Green manure of Brassicaceae containing glucosinolates is able to play a biofumigant effect in soil and has been utilized for the biological control of some soilborne plant pests and nematodes (Matthiessen and Kirkegaard, 2006; Curto et al., 2008; Larkin and Griffin, 2007). It represents a natural alternative approach to the use of chemical fumigants, such as metam sodium (Pinkerton et al., 2000; Rowe and Powelson, 2002; McGuire, 2004) or methyl bro- mide (Lazzeri et al., 2004; Mattner et al., 2008), which entered in phase-out several years ago. The utilization of biofumigant green Abbreviations: DSMs, defatted seed meals. ∗ Corresponding author. Tel.: +39 059926268; fax: +39 059928371. E-mail addresses: rosa.marchetti@entecra.it (R. Marchetti), luca.lazzeri@entecra.it (L. Lazzeri). manure crops can be partially or totally replaced by glucosinolate- containing defatted seed meals (DSMs) (Handiseni et al., 2013), that are by-products of Brassicaceae seed defatting and biodiesel indus- try. Defatted seed meals can be more easily managed than green manure in field applications, because they are less subject to con- straints in timing of incorporation into soil and the amounts to be incorporated can be quantified more easily. The decline in soil organic matter in many Mediterranean semi- arid agricultural areas is associated with a decrease in soil fertility (Moreno-Cornejo et al., 2014). Whether acting as biofumigants or not, DSMs as well as green manure may improve soil fer- tility (Moore, 2011; Mohammadi and Rokhzadi, 2012) through incorporation of large organic matter amounts potentially suitable as nutrient sources for crops (Kumar and Goh, 2000; Thorup- Kristensen et al., 2003). Organic carbon (C) and organic nitrogen (N) mineralization are tightly linked processes. While the influence of crop residue char- http://dx.doi.org/10.1016/j.indcrop.2015.04.062 0926-6690/© 2015 Elsevier B.V. All rights reserved.