Joint analysis of land, carbon and nitrogen reveals diverging trends in the sustainability of organic crops in Spain.

Autor: Guzmán GI; Laboratorio de Historia de los Agroecosistemas, Universidad Pablo de Olavide, Carretera de Utrera, km 1, 41013 Sevilla, Spain; ALIMENTTA, Think tank for the food transition, Spain. Electronic address: giguzcas@upo.es., Aguilera E; ALIMENTTA, Think tank for the food transition, Spain; Institute of Economics, Geography and Demography, Spanish National Research Council, C/Albasanz 26-28, E28037 Madrid, Spain., Carranza-Gallego G; Department of Animal Biology, Plant Biology and Ecology, Jaen University, Spain., Alonso AM; ALIMENTTA, Think tank for the food transition, Spain., Pontijas B; ALIMENTTA, Think tank for the food transition, Spain.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Nov 01; Vol. 949, pp. 174859. Date of Electronic Publication: 2024 Jul 23.
DOI: 10.1016/j.scitotenv.2024.174859
Abstrakt: The world's top ten Organic Farming (OF) countries by converted area include several Mediterranean countries, including Spain. Despite this, little is known about the consequences of OF on crop production and environmental sustainability in this country. In this article, we conduct an agronomic analysis of Spanish considerable conversion rate to OF, which tends to concentrate in certain provinces and crops. Indeed, in the case of various crops and in several provinces, the organic share of total agricultural land exceeds 20-30 %. This concentration makes it possible to compare information obtained from farmers through interviews and provincial statistical information. The study data consisted of information collected from interviews of a representative sample of organic farmers conducted in 2004 and 2020 as well as official statistical information. The results showed that no yield gap between OF and conventional farming was found for vegetables and fruit trees, while it showed an increasing trend in arable crops. Presumably, the reason is that fruit trees and vegetables generate and incorporate high levels of carbon (C) flows into the soil and have a low land cost per unit of incorporated nitrogen (N) (or can be paid for), allowing to meet crop needs and to increase soil organic matter (SOM). Conversely, in the case of rainfed arable crops, the soil C and N inputs are deficient due to the low crop residues and the high land cost of N. Consequently, SOM destruction and N deficit progressively broaden the yield gap, undermining the agroecosystem sustainability. To reverse the situation, among other measures, it is necessary to implement agricultural policies designed to make rotations with high legume ratios viable and to plant varieties presenting higher production of residues and roots, such as traditional varieties.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Beatriz Pontijas reports financial support was provided by Daniel and Nina Carasso Foundation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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