Vertisols and cambisols had contrasting short term greenhouse gas responses to crop residue management

In sustainable agriculture crop residues management should consider the interactions between soil and residue properties, which can affect the decomposition and global greenhouse gases (GHGs) emission. Through a laboratory experiment, we investigated the effect of the management (incorporation and surface placement) of wheat and faba bean residues on their decomposition and CO2, CH4 and N2O emissions from two soils, a Chromic Vertisol and an Eutric Cambisol. In the Vertisol, wheat residues increased the CO2 emission more than faba bean when left on the surface whereas no differences among residues were observed when incorporated. In the Cambisol, faba bean emitted more than wheat when left in the surface and less when incorporated. Total CH4 emissions were higher in faba bean in Cambisol for both management and only when applied in the surface in Vertisol. Total N2O emission in the Vertisol was higher when faba bean was incorporated, and wheat was left on the surface. In the Cambisol, wheat addition increased total N2O emissions by 20% compared to faba bean, with no differences between managements. Our study confirmed that contrasting properties among tested soils resulted in significant interactions with residues own degradability and their placement affecting residue decomposition, soil C and N dynamics, and GHGs emission

Impacts of arbuscular mycorrhizal fungi on nutrient uptake, N2 fixation, N transfer, and growth in a wheat/faba bean intercropping system

Arbuscular mycorrhizal fungi (AMF) can play a key role in natural and agricultural ecosystems affecting plant nutrition, soil biological activity and modifying the availability of nutrients by plants. This research aimed at expanding the knowledge of the role played by AMF in the uptake of macro- and micronutrients and N transfer (using a 15 N stem-labelling method) in a faba bean/wheat intercropping system. It also investigates the role of AMF in biological N fixation (using the natural isotopic abundance method) in faba bean grown in pure stand and in mixture. Finally, it examines the role of AMF in driving competition and facilitation between faba bean and wheat. Durum wheat and faba bean were grown in pots (five pots per treatment) as sole crops or in mixture in the presence or absence of AMF. Root colonisation by AMF was greater in faba bean than in wheat and increased when species were mixed compared to pure stand (particularly for faba bean). Mycorrhizal symbiosis positively influenced root biomass, specific root length, and root density and increased the uptake of P, Fe, and Zn in wheat (both in pure stand and in mixture) but not in faba bean. Furthermore, AMF symbiosis increased the percentage of N derived from the atmosphere in the total N biomass of faba bean grown in mixture (+20%) but not in pure stand. Nitrogen transfer from faba bean to wheat was low (2.5–3.0 mg pot -1 ); inoculation with AMF increased N transfer by 20%. Overall, in terms of above- and belowground growth and uptake of nutrients, mycorrhization favoured the stronger competitor in the mixture (wheat) without negatively affecting the companion species (faba bean). Results of this study confirm the role of AMF in driving biological interactions among neighbouring plants. and analysis, decision to publish, or preparation of the manuscript

Effects of harvesting methods on seed yield and quality of Scorpiurs muricatus L..

Scorpiurus muricatus L. is an annual legume, widely distributed in Mediterranean pastures, that is appreciated by farmers for its productivity, forage quality, and palatability. It is characterised by long flowering and ripening periods and by pod shedding. These characteristics cause high seed losses, which could reduce its seed harvest efficiency in terms of seed yield and quality. In this study, we investigated the effects on seed yield and quality of different harvesting methods (windrowing at different times with subsequent combining was compared with direct combining). Our results show that direct combining when the pods were fully ripened reduced pod losses compared with swathing methods, producing the highest yield of seed actually harvested. However, in this study, the unique climatic conditions during the pod development stage (extremely high temperatures) accelerated the ripening process, presumably limiting pod shedding

Scorpiurus muricatus L.: an interesting legume species for Mediterranean forage systems

Scorpiurus muricatus L. (prickly scorpion’s tail) is a legume species widely distributed as a spontaneous plant in Mediterranean pastures. In Sicily, farmers ascribe to this species a very high palatability and galactogogue effect, so that its abundance increases the value of the pasture. However, despite its worthy traits, the use of S. muricatus as a forage within cropping systems has not been well investigated. A field experiment was performed during two growing seasons in a semiarid Mediterranean environment to acquire information on the productivity of S. muricatus in comparison with other forage species grown in Mediterranean areas (e.g. berseem clover, burr medic, subterranean clover) and on its response to different cutting managements (cuts made in different phenological stages). Results showed that S. muricatus can provide biomass yield similar to, and in some cases higher than, that of the other forage legumes evaluated, differing from these species in its temporal distribution of the biomass accumulation. The findings contribute to define the role that S. muricatus could play in improving the productivity sustainability of the Mediterranean forage systems

Energy use efficiency of livestock farms in a mountain area of Sicily

The research aimed to evaluate the performance (in terms of energy) of livestock farms located in a Mediterranean mountain area and characterized by different stocking rates. Farm data were collected from in-person interviews of farmers of 58 farms representative of the livestock farms of the Madonie and Nebrodi mountains area (Sicily, Italy), including several parameters related to farm characteristics, animal, crop and pasture management. The farm parameters were used to calculate input and output energy values from which agroecosystem performance indicators were derived. Increasing stocking rate corresponded to a more than proportional increase in total inputs per unit area because of a greater farm dependence on external energy sources derived from agriculture (mainly for concentrate feed) and to a lower energy use efficiency. The indicator of dependence on non-renewable energy sources was, on average, very low irrespective of stocking rate. As stocking rate increased the farm autonomy indicator fell and the immediate removal indicator increased. Overall, the best agroecosystem performance in terms of energy was found on farms with lower stocking rates, higher proportions of permanent pastures to total farm area, and longer periods of exclusive grazing

Berseem-annual ryegrass intercropping: effect of plant arrangement and seeding ratio on N2 fixation and yield

Various agronomic factors can affect the productivity and the efficiency of legume-grass intercropping systems. This research was carried out in a Mediterranean semi-arid environment (37°30’N; 13°31’E; 178 m a.s.l.) with the aim to study on berseem clover- annual ryegrass mixture (Trifolium alexandrinum L. – Lolium multiflorum Lam subsp. wersterwoldicum) the effects of different plant arrangement (sowing of the two components in alternate rows or in the same row) and seeding ratios (100:0; 75:25; 50:50; 25:75; 0:100) on forage yield, nitrogen content and nitrogen fixation. The experimental design was a split-plot with four replications. The 15N isotope dilution technique was used to estimate nitrogen fixation by berseem clover. All plots were cut four times (first cut 85 DAS; rest period of four weeks). The DM yield of mixtures and pure stand clover were similar; annual ryegrass in pure stand produced the lowest yields. No significant differences for DM yield were observed due to the plant arrangement and seeding ratio in the mixture. Intercropping berseem had always a significant higher percentage of Ndfa than monocropped berseem. The %Ndfa of mixed berseem was not influenced by plant arrangement but gradually decreased when proportion of berseem in the mixture increased