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291.
This study was conducted to assess the influence of biowaste compost on soil aggregation and soil organic carbon (SOC) stabilization, in a conventional tillage agro-ecosystem. Four treatments were involved: biowaste compost (Com), fertilizers nitrogen, phosphorus and potassium (NPK) (Min), biowaste compost plus mineral N (ComN) and unfertilized control (Cnt). Compared to the control, after four years, the amount of macroaggregates decreased by 23% and 69% for Com and ComN, while SOC stock increased by 17% and 10%, respectively. Most part of the SOC increases were stored in free-microaggregates and were made up for more than 70% by mineral-associated organic carbon (MOC), while no significant variation of particulate organic C (POC) was observed. Therefore, the biowaste compost application rates and time that were practiced in the studied agro-ecosystem were effective for C sequestration, but not enough to improve the macroaggregation and the POC protection. 相似文献
292.
The Mediterranean region has been regarded as a critical hotspot for desertification due to the impact of soil degradation, the land‐use changes and the climate variations. Few large‐scale studies have been devoted to analyse trends in land sensitivity to desertification in the northern Mediterranean basin. The present paper contributes to this deserving issue by quantifying the level of land sensitivity to desertification in Italy at seven points between 1960 and 2010 at a fine spatial scale. The approach used followed the Environmentally Sensitive Area scheme that assesses changes in four key themes (climate, soil, vegetation and land management) related to land degradation processes. Italian land was classified into four levels of sensitivity to desertification (non‐affected, potentially affected, fragile and critical) according to the Environmentally Sensitive Area framework. Interestingly, although land surface area classified as ‘fragile’ and ‘critical’ grew homogeneously in Italy between 1960 and 1990, the increase observed in the most recent time period was spatially clustered and contributed to reverse the polarisation in ‘structurally vulnerable’ and ‘non‐affected’ regions observed in Italy. The paper discussed these trends in the light of socioeconomic changes that occurred in Italy after World War II. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献