Energetic sustainability of three arabica coffee growing systems used by family farming units in Espírito Santo state

Three growing systems of Arabica coffee were evaluated under the energy perspective, in the state of Espírito Santo in Brazil. The systems are conventional cultivation (CC), cultivation with good agricultural practices (CGP) and organic farming (OF). It was made a comparison of the energy flows within these three systems to show sustainable levels of each one based on production average data of several family-farming units. Therefore, we analyzed crop yield, total energy efficiency reverse (TEER), energy efficiency of ripe coffee (EERC) and non-renewable energy efficiency (NREE). OF system had values for TEER, EERC and NREE of 3.3 4.7 and 7.9 respectively. Yet CC showed values of 1.8, 1.9 and 1.6 for TEER, EERC and NREE respectively. Furthermore, CGP presented values for TEER, EERC and NREE of 0.7, 1.3 and 1.4 respectively. The highest yield was observed in CGP, reaching an amount of 1794 kg ha-1(17,455 MJ); however, this system expends more energy than it converts. Thus, over those points, OF is the most sustainable system.

Soursop seedlings: biomasses and biometric relations in different farming environments and substrates – Part II

ABSTRACT The quality of seedling is critical to obtain vigorous plants in the field. The present study aimed to assess biomasses and biometric relations of soursop seedlings. We used different substrates in protected environments. The experiment was performed at the Universidade Estadual do Mato Grosso do Sul (UFMS) (State University of Mato Grosso do Sul). Five farming environments were developed in greenhouses: one covered with low-density polyethylene film (LDPE), another with with polyethylene and heat-reflective cloth under film under 50% shading in aluminized color, monofilament cloth under 50% shading in black, thermo-reflective cloth under 50% shading in aluminized color, and an environment covered with bacuri coconut straw. Substrates were made of manure, humus, cassava branches and vermiculite at different proportions. Each of them varying from 25%, 33.3%, 50% and 75% in mixture combination. Each environment was considered an experiment. A completely randomized design was adopted and later a joint analysis of them. Agricultural greenhouse covered with LDPE and thermo-reflective cloths under 50% of shading, proportionated seedlings with greater biomass. Substrates containing manure are the most suitable for soursop seedlings. High percentages of earthworm humus produce low quality soursop seedlings. Soursop seedlings had a Dickson’s quality index around 0.335. The greenhouse covered only with LDPE film did not produce high quality seedlings.

Effect of different substrates in aquaponic lettuce production associated with intensive tilapia farming with water recirculation systems

ABSTRACT The integration of fish farming in intensive system and plant production, called "aquaponics" is practiced successfully in countries like the USA, Australia and Europe. In Brazil, this integration has attracted the attention of researchers and producers. In this context, the aim of this study was to evaluate the effect of two substrates (crushed stone number 3, CS III and flexible polyurethane foam, FPF) on the production of aquaponic lettuce, moreover, to show that the residual water from intensive tilapia production provides sufficient qualitative characteristics for competitive production of lettuce without adding commercial fertilizers. The treatment in which FPF was used provided higher concentrations of macro and micronutrients in the shoots, higher production of fresh matter of shoots (95.48 g plant-1) and a larger number of leaves (14.90) relative to CS III. These results were attributed to the lower post-transplanting stress and the higher water retention time provided by the FPF. The residual water from tilapia intensive farming can provide sufficient nutrients for the production of lettuce, making the supplementary fertilization with commercial products unnecessary. Thus, the FPF presents the most suitable conditions to be used as substrate in aquaponics system with recirculation of the residual water from the intensive tilapia farming.