Soil conservation and ecosystem services from agroforestry systems: a GIS-based approach for soil erosion in Central Italy

Preserving natural resources, such as soil, is one of the major challenge for agriculture, in the view of developing sustainable adaptation strategies to climate change. Soil loss by water erosion is a critical issue in the Mediterra - nean region due to high rainfall erosivity caused by the increased frequency of extreme precipitation events. In Tuscany, the risk of soil erosion is exacerbated on arable soil of hilly areas, where the persistent application of conventional tillage is associated with: (i) long periods with bare soils within the crop rotation, (ii) poor herba- ceous vegetation cover due to low biomass productivity and (iii) scarce presence of trees on farmland. Agrofore - stry systems - “the practice of deliberately integrating woody vegetation (trees or shrubs) with crop and/or ani- mal systems to benefit from the resulting ecological and economic interactions” - can reduce soil erosion risk by enhancing cover-management factor. In this study the (R)USLE (Revised Universal Soil Loss Equation) was im- plemented on a GIS-based model in order to assess the potential of diferent agroforestry systems in decreasing soil erosion risk on arable land below the tolerance threshold (11 Mg ha-1 yr-1). The JRC-EU map proposed by Pa- nagos et al. (2015) was used for rainfall erosivity, whereas the agroforestry P-factor values were derived from Delgado & Canter (2012). The reference scenario, based in current soil uses (Corine Land Cover 2012) allowed to determine the baseline of potential soil losses on arable land in Tuscany and to identify areas characterized by the highest risk of erosion. About 50% of the cropland in the study area, 450,000 ha, has a severe soil erosion risk, more than 33 Mg ha-1 yr-1 of soil loss.The development of alternative scenarios, based on the possible implemen- tation of agroforestry systems, allowed to highlight that: (i) alley cropping systems (P-factor from 0.1 to 0.5) would reduce soil loss rate under the tolerance threshold on 60 % of the arable land of Tuscany; (ii) the 11% of the arable land would urgently need high conservative agroforestry practices (P-factor less than 0.1) in order to reduce soil loss below the tolerance threshold

A multi-adaptive framework for the crop choice in paludicultural cropping systems

The conventional cultivation of drained peatland causes peat oxidation, soil subsidence, nutrient loss, increasing greenhouse gas emissions and biodiversity reduction. Paludiculture has been identified as an alternative management strategy consisting in the cultivation of biomass on wet and rewetted peatlands. This strategy can save these habitats and restore the ecosystem services provided by the peatlands both on the local and global scale. This paper illustrates the most important features to optimise the crop choice phase, which is the crucial point for the success of paludiculture systems. A multi-adaptive framework was proposed. It was based on four points that should be checked to identify suitable crops for paludicultural cropping system: biological traits, biomass production, attitude to cultivation and biomass quality. The main agronomic implications were explored with the help of some results from a plurennial open-field experimentation carried out in a paludicultural system set up in the Massaciuccoli Lake Basin (Tuscany, Italy) and a complete example of the method application was provided. The tested crops were Arundo donax L., Miscanthus × giganteus Greef et Deuter, Phragmites australis L., Populus × canadensis Moench. and Salix alba L. The results showed a different level of suitability ascribable to the different plant species proving that the proposed framework can discriminate the behaviour of tested crops. Phragmites australis L.was the most suitable crop whereas Populus × canadensis Moench and Miscanthus × giganteus Greef et Deuter (in the case of biogas conversion) occupied the last positions in the ranking

Rewetting in Mediterranean reclaimed peaty soils and its potential for phyto-treatment use

A pilot experimental field combining rewetting of reclaimed peaty soils and water phyto-treatment was set up in the Massaciuccoli Lake basin (Tuscany, Italy) to reduce the water eutrophication and peat degradation caused by almost a century of drainage-based agricultural use. In this paper, we investigated the restoration process occurring consequently to the conversion of a drained area in a natural wetland system (NWS) (the partial top soil removal, the realization of a perimeter levee to contain the waters, the rewetting with the drainage waters coming from the of surrounding cultivated areas) and the capability of the spontaneous vegetation to catch nutrients acting as a vegetation filter. To follow the restoration process over time (2012e2016), we used a mixed approach merging phytosociological surveys with ortophotos taken by an Unmanned Aerial Vehicle (UAV). During the last year of observation (2016), we performed destructive sampling on the most widespread plant communities in the area (Phragmites australis and Myriophyllum aquaticum community) to quantify the biomass production and the uptake of nitrogen and phosphorus. Stands of Phragmites australis (Cav.) Trin. ex Steud. yielded more than Myriophyllum aquaticum (Vell.) Verdc. (4.94 kg m-2 vs 1.08 kg m-2). M. aquaticum showed higher nutrient contents (2.04% of N and 0.35% of P), however P. australis was able to take up more nutrients within the NWS because of its larger cover and productivity. In the perspective of maximizing the plant development and consequently the amount of nutrients extracted from treated waters, the authors suggest 4-5 year-long-harvesting turns, better occurring in spring-summer

Giant reed (Arundo donax L.) as energy crop in Central Italy: A review

In the European Union energy security have been driving the search for economically viable and environmentally sustainable renewable energy sources since the 90’s. Energy crops could represent a good opportunity to combine the energy goals with the conservation of farmer incomes and the global climate change control. Giant reed (Arundo donax L.) is a perennial rhizomatous grass particularly attractive for energy production because of a high yield potential, a generally positive environmental impact and a good attitude to energy conversion. Long-term studies carried out in Central Italy confirmed its high production level, in both fertile and marginal lands (aboveground yields from 38 to 20 t ha–1 year–1). In addition, the crop highlighted a high growth rate at the beginning of the growing season, progressively decreasing in summer when high temperature and low water availability occurred. Giant reed nutrient requirements were generally low and part of nutrient stocks were remobilized from the rhizome to the aboveground biomass over the spring, with the opposite flow occurring in autumn. From an environmental point of view giant reed showed a positive energy balance with a high-energy efficiency. Compared to other energy crops, giant reed showed the lowest GHG emissions per unit of energy and the best performance in terms of cost per ton of dry biomass or per unit of energy. To improve knowledge on giant reed and to favour the diffusion of energy crops in Italian cropping systems, further studies are needed to analyze the long-term effects of giant reed on soil fertility and the optimal soil management after its cultivation. In our researches the environmental impacts of giant reed and its production costs were referred to the production phase. Therefore, there is the need to extend the research activity to the whole energy chain and to identify the most sustainable conversion technologies (e.g. biogas, 2nd generation bioethanol, etc.) for the different environments

Changes in soil quality following poplar short-rotation forestry under different cutting cycles

In the last decade, the change of energy concept induced by global warming and fossil fuel depletion together with the advances in agriculture towards a multifunctional and a more sustainable use of rural areas promoted the development of biomass crops. In this regard, Populus is largely utilised in short-rotation forestry (SRF), as it is known to be a fast-growing tree, producing large yields and having a high energy potential. Most studies focused on economic-productive and energetic aspects of Populus plantations, whereas their impact on soil quality and health have been poorly investigated. In this study, the main soil chemical parameters, microbial biomass and activity were assessed aiming at evaluating the impact of Populus SRF under one, two and three-year cutting cycles (T1, T2 and T3) in comparison with an intensive food cropping system (wheat-soybean rotation, WS). In addition, arbuscular mycorrhizal (AM) fungal inoculum potential was measured using root colonisation (RC) and number of entry points (EP). In the 0-10 cm soil depth, pH, phosphorus (P), total nitrogen (N) and soil organic carbon (SOC) were significantly affected by the management. In comparison with WS, Populus SRF treatments produced significant pH decreases together with N and SOC increases, these last ones ranging from 11 to 34% and from 21 to 57%, respectively. Under T3 soil pH decreased of 0.25 units, while P, N and SOC increased of 10, 34 and 57%, respectively, in comparison with WS. Microbial biomass and soil respiration under SRF showed also mean increases of 71 and 17%, respectively. Under SRF treatments, Lolium perenne, commonly observed in all field plots, was more than twofold colonised by AM fungi in comparison with WS, while the number of EP, observed on Lactuca sativa used as a test plant, showed values ranging from 8 to 21 times higher. The present study shows the potential of a Populus SRF to improve soil chemical, biochemical and biological quality parameters in comparison with an intensive food cropping system