Visual assessment of the impact of agricultural management practices on soil quality

The intensification of agricultural practices to increase food and feed outputs is apressing challenge causing deterioration of soil quality and soil functions. Such achallenge demands provision of empirical evidence to provide context-sensitive guid-ance on agricultural management practices (AMPs) that may enhance soil quality.The objectives of this study are to identify the most promising AMPs (and their com-binations) applied by farmers with the most positive effects on soil quality and toevaluate the sensitivity of the soil quality indicators to the applied AMPs. The effectof selected AMPs on soil quality was assessed using a visual soil assessment tool ina total of 138 pairs of plots spread across 14 study site areas in Europe and Chinacovering representative pedo-climatic zones. The inventory and scoring of soil qual-ity were conducted together with landowners. Results show that 104 pairs show apositive effect of AMPs on soil quality. Higher effects of the AMPs were observedin lower fertile soils (i.e., Podzols and Calcisols) as opposed to higher fertile soils(i.e., Luvisols and Fluvisols). For the single use applications, the AMPs with positiveeffects were crop rotation; manuring, composting, and no-tillage; followed by organicagriculture and residue maintenance. Cluster analysis showed that the most promis-ing combinations of AMPs with the most positive effects on soil quality are composedof crop rotation, mulching, and min-till. The agreement between scientific skills andempirical knowledge in the field identified by the farmers confirm our findings andensures their applicability

Restoration of nitrogen cycling community in grapevine soil by a decade of organic fertilization

Traditional intensive agricultural practices negatively impact soil quality, leading to increased erosion in the Mediterranean region. In contrast, sustainable management practices that have utilized organic fertilization over a decade improved soil quality in the Spanish "Pago Casa Gran" vineyard, Valencia. Grape prunings, combined with sheep manure or leguminous cover, have improved soil chemical and biological parameters, such as organic carbon, nitrogen content, respiration, PLFA, total DNA and aggregation, however, there has been a lack of information on their effect on specific functional microbial groups. The nitrogen cycling community of the soil was investigated by quantification of genes involved in key pathways, in particular nitrogen fixation, denitrification and nitrification. The abundances of bacterial nifH, nosZ, nirS and nirK genes significantly increased under a decade of organic fertilization when compared to inorganic fertilization, and was linked to increased soil organic carbon. The abundance of nifH was lower where fertilizers rich in ammonia and nitrate were used and its increase under organic fertilization was more related to the availability of organic carbon than to the nature of the organic amendment. Archaeal amoA abundance did not correlate with the type of fertilization and the bacterial amoA abundance was more dependent on the availability of soluble nitrogen than on the type of management. An increase in nosZ under organic fertilization may suggest a greater abundance of denitrifiers with the ability to reduce nitrous oxide to nitrogen gas, reducing greenhouse gas emission. Our results indicate that soil microbial communities involved in biological nitrogen cycling, in particular nitrogen fixation and denitrification, are more abundant under management practices that include organic fertilization when compared to traditional agricultural practices. It may therefore be recommended that organic fertilization be utilized in agricultural systems to assist with sustaining healthy soils

El papel de las cenizas en la hidrofobicidad del suelo en un área mediterránea afectada por un incendio forestal: estudio en condiciones de campo

Ministerio de Ciencia e Innovación de España- Proyecto HYDFIRE-CGL2010-21670-C02-0