The aim of this study was to analyze the influence of organic fertilizer on the availability of natural food (plankton and benthos) and water quality. Two fertilization protocols were adopted using inorganic and organic fertilizers with shrimp (stocked treatment) and their controls (unstocked treatment). Experimental units consisted of 12 circular fiberglass tanks (500 l) with estuarine sediment, individual aeration and no water exchange. In stocked treatments were used 40 juveniles/m², and they were fed with 35% crude protein marine shrimp ration, three times a day. Under the organic fertilization protocol, the plankton showed higher abundance of Nitzschia and rotifers, the phytobenthos consisted mainly of Nitzschia, Amphiprora and Oscillatoria, the epibenthos was represented mainly by nematodes and rotifers, and the macro-invertebrates were mainly oligochaetes. In relation to inorganic fertilization, the plankton was represented mainly by Coscinodiscus and rotifers, the phytobenthos consisted mainly of Amphiprora and Oscillatoria, the epibenthos was represented mainly by nematodes and rotifers, and the macro-invertebrates were mainly oligochaetes. Dissolved oxygen was higher for organic fertilizer (6.16 ± 0.98 mg/l) than for inorganic (5.92 ± 1.19 mg/l) while the other water quality parameters did not present significant differences. Survival was similar in the two fertilization regimes (96.6%). Final body weight was 11.89 ± 1.73 g for the inorganic fertilizers and 12.28 ± 1.71 g for organic fertilizer. It is concluded that wheat bran showed good performance in the water quality without exchange, in the availability of natural food, and in the growth and survival of the shrimps in the microcosms.

Sustainable management of natural resources under economic, environmental and social perspective, needs to consider a fair balance between its uses and availability. Sustainable agriculture goal is to establish innovative and new farm tools and service capacities that help the intensive farm sector to optimize input management (energy, nutrients and water) and productivity. The main objective of this paper was to investigate, in a durum wheat production system in central Italy under Mediterranean conditions, the following aspects: (i) environmental sustainability of fertilization treatments through the energy inputs/outputs analysis and reduction of Nitrate (N-NO₃) in water cycle; (ii) agricultural system agronomic and economic performance and (iii) to identify regulatory and economic instruments actually in place to promote sustainable fertilization. To describe and address the sustainability assessment of durum wheat production system we adopt the “Water Energy Food nexus” (WEF) as conceptual framework. The findings of this research showed that there is a great difference between the marketable yields obtained with mineral fertilization strategies and those by organic fertilizer, while considering the environmental sustainability, our results provide evidences of the significance of the reduction of energy use and the high value of renewable energies and the decreasing of non-renewable one. At the same time the reduced impact of groundwater quality due to the organic fertilizer seems to be an interesting result to be analyzed in the long-term perspective. The contraposition between economy and environment is one of the main challenges to be solved through adequate policy instruments.