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CropSyst is a mechanistic model developed for simulating the growth and development of potentially all herbaceous crops under potential and water/nitrogen (N)-limited conditions. Although the model has been widely used for many crops under different pedo-climatic and management conditions, studies on the simulation of water and N balance for flooded rice are lacking. We evaluated the CropSyst model for simulating the N balance of north-Italian rice fields for scatter-seeded rice grown under continuously flooded conditions. In order to calibrate and validate the model for the processes involved with soil N transformation, data collected in field experiments carried out in northern Italy between 2002 and 2004 were used. The results show the robustness of the model in reproducing the course of the measured soil mineral nitrogen content: the Modeling Efficiencies which describe the agreement between measured and simulated trends, are in most cases positive and the model error fell almost always within the experimental error on the measurements (P = 0.95). Moreover, the model showed the same level of reliability while simulating the nitrogen balances under different levels of nitrogen fertilization, thus depicting it as suitable for comparing N fertilization scenarios. This first attempt at using a model for simulating the nitrogen balance under flooded conditions encourages further studies because of the need of effective tools for optimizing the nitrogen management of flooded rice systems, considered significant sources of groundwater pollution and greenhouse gases in many European rice districts.

Dry-seeded delayed-flooded rice in Italy is important in some areas with high sand content. The effects of N application timing and rates on grain yield, milling yield, plant height, total biomass, harvest index (HI) and crop N content were evaluated for dry-seeded delayed-flooded rice in Italy to increase the N use efficiency and to study N fertilizer recommendations. Two widely grown non-semi-dwarf varieties were studied: Drago and Loto. Three N rates were used: 60, 120 and 180 kg N ha−1. For each rate the fertilizer was applied in seven splits across three growth stages: pre-sowing, pre-flooding and panicle differentiation. Drago produced higher yields and N application at all stages increased yield. Late N application caused the development of secondary sterile tillers, decreasing harvest index. Loto responded to earlier N applications but not to late N applications. In contrast with other trials outside Italy, pre-plant N fertilization was effective in increasing yield. Brown rice and total milled rice yields were higher for Loto. Increasing the applied N rate increased the head rice yield range. With low N no low values were recorded and variation between splits was small. With high N the highest head yield was observed with split application. Height was significantly affected by N rate and split, with a range of 65 to 92 cm and 54 to 86 cm for Drago and Loto, respectively. N application at tillering was more effective. N rate and split affected biomass and decreased HI. Crop N content at maturity was affected by late N application and by total applied fertilizer. N content in the panicle showed lower variation with N split and rate and was negatively correlated with yield. At 120 and 180 kg N ha−1all nitrogen applied pre-flooding gave good results in both sites, but the best results were obtained with N split at pre-sowing and pre-flooding, with low yield increase moving from 120 to 180 kg N ha−1. We recommend late N applications for Drago (medium-late variety), but not for Loto (early variety).

Selected lines of aromatic rice from American cv. A301 were cultivated in Italy, and the agronomic traits and chemical properties related to their aroma were studied. The most characteristic compound responsible for aromatic rice, 2-acetyl-1-pyrroline, was quantified in all lines. Line B5-3, characterized by high 2-acetyl-1-pyrroline content, was investigated in greater detail for its volatile components and was compared with a commercial Basmati rice. Volatiles were collected by steam-distillation. Several classes of compounds were identified and quantified in both samples, including hydrocarbons, aldehydes, alcohols, ketones, heterocyclic, terpenes, disulfides, and phenols. Hexanal was the most abundant compound in both samples, followed by pentanal, 2-acetyl-1-pyrroline, hexanol, benzaldehyde, oct-1-en-3-ol, 4-vinylguaiacol, indole, and trans-2- nonenal. 2-Acetyl-1-pyrroline was present at 570 and 2,350 ppb in Basmati and B5-3, respectively.

Since the Green Revolution, worldwide agriculture has been characterized by a typical top–down approach. The degree of autonomy, creativity, and responsibility of farmers has been limited by the continuous external inputs of chemicals, machinery, advice, subsidies and knowledge.