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The effects of organic fertilizer application on heavy metals accumulation in both soil and plants and on the main soil fertility parameters have been evaluated in a long-term field experiment. The research was carried out in a Mediterranean environment (Rutigliano, Southern Italy – 41° 01′ latitude N, 4° 39′ longitude E, 112 m a.s.l.) since the autumn of 2001 in permanent rain-fed meadows of alfalfa (Medicago sativa L.) and cocksfoot (Dactylis glomerata L.). Two organic materials, Municipal Solid Waste (MSW) compost and Olive Pomace (OPC) compost, were compared to nitrogen (cocksfoot) and phosphorus (alfalfa) mineral fertilizer treatments. The results showed that at the end of the first four years, the MSW and OPC composts application did not cause any heavy metals accumulation in soil and plants. Only the Zn reached a high level in the cocksfoot experimental soils. In addition, these organic materials allowed significant increases of extracted and humified soil organic carbon in the plots of both fodder...

Nitrogen (N) is one of the most growth restricting nutrients in cereal grain and represents one of the highest input costs in agricultural systems; therefore, environmental and economic considerations require the effective use of N fertilizer in plant production. This study was conducted for three years to better understand wheat plant response to optimize N fertilizer and how to reduce the risk of ground water pollution. Two of the most important durum wheat cultivars in Southern Italy and four N fertilization levels (0, 60, 120, and 180 kg N ha− 1, indicated as N0, N60, N120, and N180, respectively) were compared in this experiment. During plant growth, fresh and dry matter, plant nutritional state (SPAD readings and stem nitrate content), and N uptake were determined. At harvest, plant N content, N uptake, grain yield, yield components and quality were determined, allowing the calculation of the pre- and postanthesis N uptake and the N utilization efficiency indices. Furthermore, at the beginn...

The application of conventional agricultural practices, e.g. deep soil tillage and repeated, plentiful mineral fertilisation, can lead to a progressive deterioration of soil fertility, especially in Mediterranean environments characterised by scanty rains and high summer temperatures. As a consequence, to maintain high levels of both crop productivity and soil organic matter and to improve some soil properties, a reduction of agricultural inputs and a greater supply of organic material are needed. In the light of these considerations, we carried out a two-year field experiment in Southern Italy to determine the effects of reduced soil tillage and municipal solid waste compost application on growth parameters, production and quality of sugar beet crops, and on both soil chemical characteristics and mineral nitrogen deficit. Two soil tillage depths were compared: conventional tillage, till 40–45 cm and shallow tillage, at 15–20 cm. Within each soil tillage, the following N-fertilising strategies were tested: (1) mineral fertilisation, with 100 kg N ha−1; (2) organic fertilisation with municipal solid waste compost at 100 kg N ha−1; (3) mixed fertilisation, with 50% of organic N as municipal solid waste compost, and 50% of mineral N; and (4) slow-release organic-mineral N fertiliser, at 100 kg N ha−1. All these treatments were compared with a lower level of mineral fertiliser at 50 kg N ha−1, and with an unfertilised control. Our findings show first the absence of a significant difference in root and sucrose yields between reduced tillage and deep tillage; as shown by roots (36.02 t ha−1) and sucrose (3.41 t ha−1) yields for reduced tillage and 35.76 and 3.51 t ha−1, respectively, for the deepest tillage. Secondly, among the N treatments, the mixed organic-mineral N fertilisation gave productions statistically not different from mineral N fertilisation; as shown by root yields (36.38 versus 36.40 t ha−1) and sucrose yields (3.56 versus 3.65 t ha−1). Third, the mixed organic-mineral N induced a reduction of 13.2% in α-amino N content by comparison with the mineral treatment of 100 kg N ha−1. Fourth, our results showed that the applications of the municipal solid waste compost increased the extracted and the humified organic carbon by +27.7 and +25.4%, compared with the mineral fertiliser, and did not raise the content of heavy metals. These findings highlighted that in Southern Italy it is sustainable to adopt alternative sugar beet production, safeguarding crops’ quantitative and qualitative performance, decreasing the production costs and using the natural resources better.

Agronomic value and environmental impact of two composts were evaluated in a three-year field experiment (2002, 2003 and 2004) on alfalfa and cocksfoot in Southern Italy. The effects of Municipal Solid Waste compost (MSW), Olive Pomace Compost (OPC), mineral fertilizer (Min) (phosphorus as 75 kg ha−1 for alfalfa and nitrogen as 50 kg ha−1 for cocksfoot) and an unfertilized treatment (Contr) were compared on crop yield, soil characteristics and environment impact. During the cropping cycles, fresh and dry weights, plant nitrogen status (leaves SPAD readings and petiole nitrate content) and plant total N content were determined for calculating the protein content and the plant N uptake. Moreover, at the beginning and the end of the research, chemical soil characteristics and heavy metal levels were also determined. The results indicated that in cocksfoot fertilized with MSW and OPC composts, the mean cumulative dry weight increased by 20.85 and 16.51%, respectively compared to the control, but it was signif...

Nutrient balances for N, P2O5 and K2O have been determined for different rotations and cultural treatments on a soil near to the sea in southern Italy (Metaponto - Matera). The soil Typic Epiaquert had poor drainage with a superficial water table (from 0.4 to 0.8 m) which could cause Na accumulation in the soil profile and modify the chemical-physical soil characteristics. The experiment compare three rotations: continuous sorghum with three irrigation treatments; and traditional and minimum tillage on durum wheat with soybean and durum wheat with guar. At the harvest of each crop soil samples from 0–20, 20–40 and 40–60 cm depth were taken to determine N-NO3, N-NH4 available P2O5 and exchangeable K2O; and crop samples (grain and residues) to determine N, P2O5 and K2O. The results showed a large uptake of N, P2O5 and K2O in all rotations and the balance (input-output) for K2O was always negative. There were small differences among experimental treatments.

This research was carried out at Foggia (southern Italy) on a silty-clay soil (Typic Chromoxererts) in an experimental field characterized by hot-arid summers, cold winters and scanty and sporadic rains.Roots distribution, agronomic parameters and nitrogen balance were recorded at harvest of broad beans after durum wheat in a two-year rotation. Four different tillage methods (A — traditional mouldboard ploughing; B — ripper subsoiling; C — skim ploughing; D — minimum tillage) and three N rates (0, 50, 100 kg N ha−1 only to wheat) were used. Nitrogen balance in selected “treatment” was done by comparing soil mineral nitrogen variations (N-NO3 + exchangeable N-NH4), in all experimental plots, with nitrogen distribution within broad bean plant organs. The findings show a strong interaction between tillage methods and N rates as affected by the modifications of water infiltration, temperature gradients, organic carbon turnover and soil nitrogen transport and transformations.

The research, started 1993, was carried out at Foggia (Southern Italy) on a silty-clay soil with “accentuated thermo-Mediterranean” climate. The field experiment was laid out in randomized blocks with three replications, comparing three types of fertilizer (Al: mineral fertilizer, A2: organic + mineral fertilizer, A3: municipal solid waste compost) and three N doses (40, 80, 120 kg N ha−1) on Autumn-sown sugar beet, and durum wheat, both cropped each year on adjacent plots. Product quality was evaluated determining polarization angle and α-amino N, Na+ and K+ concentrations of sugar beet pulp and the protein content of durum wheat grain. The best yield responses and quality characteristics of sugar beet and durum wheat in MSW-amended soil depend on differing previous crops and agronomical inputs used over many years in the experimental field. Agronomical benefits of MSW-compost applied to the vertisol type soil used were observed also in relation to mineralization of organic N contained in MSW-compost that gradually released N during the cropping season. When MWS-compost was applied for 4 years the a-amino N and Na+ contents of sugar beet pulp decreased but the supply of mineral N to durum wheat plants provided adequate requirements for grain d.m. accumulation.

A two-year field experiment (2001 and 2003) was carried out in a Mediterranean environment to study the effects of municipal solid waste (MSW) compost application compared with mineral nitrogen (N) fertilization on the agronomic performance and N utilization of a tomato crop, in rotation with durum wheat. The research was conducted in the south of Italy where five N treatments and two soil tillage depths (40-45 cm and 10-15 cm) were compared. The N treatments were: MSW compost at 140 kg ha−1 (Ncom); mineral N fertilizer at 140 kg ha−1 (Nmin); MSW compost combined with mineral N fertilizer (Nmix) (70 kg ha−1 as organic N plus 70 kg ha−1 as mineral N); mineral N fertilizer at 70 kg ha−1 combined with two applications of foliar fertilizer (Nfito) (3 kg ha−1 as hydrolyzed proteins), and an untreated control (Contr). During cropping cycles, growth parameters and plant N status (SPAD readings and petiole nitrate content) were determined; at harvest the marketable, overripe, green fruit, total yield, yield compo...