Marco Mazzoncini

Brassica carinata as an alternative oil crop for the production of biodiesel in Italy: agronomic evaluation, fuel production by transesterification and characterization.

In this study, the non-food use of Brassica carinata oil for biodiesel production was investigated. B. carinata, a native plant of the Ethiopian highlands widely used as food by the Ethiopians, has recently become object of increasing interest. This is due to its better agronomic performances in areas such as Spain, California and Italy that are characterized by unfavorable environmental conditions for the cultivation of Brassica napus (by far the most common rapeseed cultivated in continental Europe). The agronomic performance and the energetic balance described here confirmed that B. carinata adapted better and was more productive both in adverse conditions (clay- and sandy-type soils and in semi-arid temperate climate) and under low cropping system when compared with B. napus. The biodiesel, produced by transesterification of the oil extracted from the B. carinata seeds, displayed physical–chemical properties suitable for the use as diesel car fuel. A comparison of the performance of B. carinata oil-derived biodiesel with a commercial biodiesel and petroleum diesel fuel was conducted as regards engine performance, regulated and unregulated exhaust emissions. These results make B. carinata a promising oil feedstock for cultivation in coastal areas of central-southern Italy, where it is more difficult to achieve the productivity potentials of B. napus, and could offer the possibility of exploiting the Mediterranean marginal areas for energetic purposes.

Changes in weed community composition as influenced by cover crop and management system in continuous corn

Abstract Weed suppression by cover crops grown during the winter fallow period in continuous corn may lead to a reduction in herbicide use. Rye, crimson clover, and subterranean clover cover crops were compared with corn stubble under a conventional management system (CS) that included plowing and use of preemergence residual herbicides and a low-input management system (LIS) that included no-tillage and use of a presowing nonresidual herbicide for three consecutive years (1994–1996). Cover crop and above-ground weed biomass prior to desiccation were not influenced by management system. Cover crop biomass ranged from 1,420 to 5,657 kg ha−1 for rye, from 563 to 4,217 kg ha−1 for crimson clover, and from 563 to 4,248 kg ha−1 for subterranean clover. At crop planting, rye reduced weed biomass from 54 to 99%, crimson clover from 22 to 46% (with a negative value in 1995), and subterranean clover from 21 to 67%. Weed growth suppression was usually higher in years when cover crop biomass was higher. There were no differences in weed suppression by cover crops later in the season (corn in the fourth leaf stage), while total weed density was higher in LIS than CS in 2 of 3 yr. Total weed cover at corns ‘full dent’ stage ranged from 1 to 7% in CS and from 24 to 47% in LIS. Cover crops influenced weed composition only in years when cover crop growth was high; otherwise their effect was masked by that of the management system. Weed communities showed higher diversity under LIS than under CS. Consistency of associations between weed species and treatments over sampling dates and years was found especially for some of the species associated with LIS. After 3 yr, redroot pigweed, common lambsquarters, and black nightshade were regularly associated with rye-LIS at an early corn growth stage; this may indicate a species shift toward a more troublesome composition. Nomenclature: Dicamba; glyphosate; nicosulfuron; terbuthylazine; black nightshade, Solanum nigrum L. SOLNI; common lambsquarters, Chenopodium album L. CHEAL; corn, Zea mays L.; crimson clover, Trifolium incarnatum L.; redroot pigweed, Amaranthus retroflexus L. AMARE; rye, Secale cereale L.; subterranean clover, Trifolium subterraneum L.

Effects of conventional and minimum tillage on winter oilseed rape (Brassica napus L.) in a sandy soil

Abstract A 3-year (1986–1988) comparison between conventional (CT) (25 cm deep ploughing) and minimum (MT) (10–15 cm deep disk harrowing) tillage was carried out in southwest Tuscany on a very sandy soil (Typic Xeropsamment) where oil rapeseed was cultivated. The CT plots showed a greater water retention capacity in the deeper horizons than the MT plots. Moreover CT was characterized by a quicker water rate of depletion in the upper soil layers when evapotranspirative demand was high. The bulk density and penetration resistance of the ploughed soil, measured to 30 cm depth, were less under CT than under MT. The presence of subsurface compacted soil layers as the result of continuous MT caused a progressive worsening of soil conditions for plant root growth and, consequently, a reduction of root system mass and tap-root length compared with the ploughed plots. However, rapeseed grain and biomass yields under CT and MT never differed significantly. Finally, MT use was connected with remarkable reductions (55% on average) of working time, fuel consumption, energy requirement and cost when compared with CT.

Unmanned Aerial Vehicle to Estimate Nitrogen Status of Turfgrasses

Spectral reflectance data originating from Unmanned Aerial Vehicle (UAV) imagery is a valuable tool to monitor plant nutrition, reduce nitrogen (N) application to real needs, thus producing both economic and environmental benefits. The objectives of the trial were i) to compare the spectral reflectance of 3 turfgrasses acquired via UAV and by a ground-based instrument; ii) to test the sensitivity of the 2 data acquisition sources in detecting induced variation in N levels. N application gradients from 0 to 250 kg ha-1 were created on 3 different turfgrass species: Cynodon dactylon x transvaalensis (Cdxt) ‘Patriot’, Zoysia matrella (Zm) ‘Zeon’ and Paspalum vaginatum (Pv) ‘Salam’. Proximity and remote-sensed reflectance measurements were acquired using a GreenSeeker handheld crop sensor and a UAV with onboard a multispectral sensor, to determine Normalized Difference Vegetation Index (NDVI). Proximity-sensed NDVI is highly correlated with data acquired from UAV with r values ranging from 0.83 (Zm) to 0.97 (Cdxt). Relating NDVI-UAV with clippings N, the highest r is for Cdxt (0.95). The most reactive species to N fertilization is Cdxt with a clippings N% ranging from 1.2% to 4.1%. UAV imagery can adequately assess the N status of turfgrasses and its spatial variability within a species, so for large areas, such as golf courses, sod farms or race courses, UAV acquired data can optimize turf management. For relatively small green areas, a hand-held crop sensor can be a less expensive and more practical option.

Effects of tillage on porosity and microstructure of a loam soil

Abstract Changes in porosity, shape, size and length of pores and microstructure in a loam soil under different types of tillage were examined. A micromorphological method was used to evaluate soil structure, characterizing porosity in soil thin sections prepared from undisturbed soil samples by means of electro-optical image analysis (Quantimet 720). Results showed that both total porosity and number of pores in topsoil were not significantly different among the plots under different types of tillage. Below the topsoil (10–15 cm) in the plots tilled by a disc harrow porosity decreased substantially making for a massive structure. In the 25–30 cm layer porosity was not significantly different in plots ploughed to a depth of 25 cm than in those ploughed to a depth of 50 cm. In the chisel ploughed plots porosity seemed to be more homogeneously distributed along the Ap horizon. Modifications in pore shape, size distribution and length and in microstructure were also observed. Surface crusts formed frequently in ploughed plots.

Effect of different cover crops on organic tomato production

When animal husbandry is not included in organic farming systems, green manure may be crucial to preserve or increase soil organic matter content and to ensure an adequate N supply to crops. Different species, both legumes and nonlegumes, may be used as cover crops. The present research was carried out to investigate the effect of different green manure crops [oats and barley mixture ( Avena sativa L. and Hordeum vulgare L.), rye ( Secale cereale L . ), brown mustard ( Brassica juncea L.), flax ( Linum usitatissimum L.), pigeon bean ( Vicia faba L . var. minor )] on the production of the following tomato crop. A field trial was conducted for two cropping seasons (2003–2004 and 2004–2005) in a commercial organic farm. The yield of tomato crop was positively affected by pigeon bean, although statistically significant differences in comparison with the other treatments were observed only in 2004–2005, when the experiment was conducted in a less fertile soil. This was probably due mainly to the effect of the pigeon bean cover crop on N availability. In fact, this species, in spite of a lower biomass production than the other cover crops considered in the study, provided the highest N supply and a more evident increase of soil N-NO 3 . Also, cover crop efficiency, evaluated using the N recovery index, reached higher values in pigeon bean, especially in the second year. The quality of tomato fruits was little influenced by the preceding cover crops. Nevertheless, when tomato followed pigeon bean, fruits showed a lower firmness compared to other cover crops, and in the second year this was associated with a higher fruit N content.

Effects of conventional and alternative management systems on soil phosphorus content, soil structure, and corn yield

Abstract Conventional management practices have been associated with increased soil erosion and organic matter loss and the contamination of surface and ground water. Alternative agriculture systems which minimize external chemical inputs and degradation of soil and water resources represent alternatives to conventional management practices. Four different management practices were compared on an alluvial silty loam soil cultivated to grow corn (Zea mays L.). The effects of conventional and reduced tillage and of different chemical inputs on the distribution of phosphorus (P) concentration and on soil porosity were investigated. Results showed that the highest P content was detected in the topsoil (0–10 cm) of the minimum tilled plots even though the amount of P fertilizer added was much lower than the amount added in the conventionally tilled plots. The total porosity was significantly higher in the minimum tilled soil and was related only to the tillage technique. Since the higher porosity was mainly du...