Cadmium phytoextraction capacity of white lupine ( Lupinus albus L.) and narrow-leafed lupine ( Lupinus angustifolius L.) in three contrasting agroclimatic conditions of Chile

The phytoextraction process implies the use of plants to promote the elimination of metal contaminants in the soil. In fact, metal-accumulating plants are planted or transplanted in metal-contaminated soil and cultivated in accordance with established agricultural practices. The objective of the present study was to evaluate the productivity and Cd phytoextraction capacity of white lupine ( Lupinus albus L.) and narrow-leafed lupine ( Lupinus angustifolius L.), as well as the effect on residual Cd concentration in the soil. Both species of lupines were grown at three CdCl2 rates (0, 1, and 2 mg kg-1), under three agroclimatic conditions in Chile in 2013. In the arid zone (Pan de Azúcar, 73 mm precipitation), narrow-leafed lupine production was significantly (P < 0.05) higher than white lupine (4.55 vs. 3.26 Mg DM ha-1, respectively). In locations with higher precipitation (Santa Rosa, 670 mm; Carillanca, 880 mm), narrow-leafed lupine DM production was slightly higher than in Pan de Azúcar, but white lupine was approximately three times higher. Total plant Cd concentrations in white and narrow-leafed lupine increased as Cd rates increased in the three environments, but they were much higher in narrow-leafed lupine than white lupine; 150%, 58%, and 344% higher in Pan de Azúcar, Santa Rosa, and Carillanca, respectively. Cadmium uptake (g Cd ha-1) and apparent recovery were also higher (P < 0.05) in narrow-leafed lupine in two environments (Pan de Azúcar and Carillanca). These results suggest that narrow-leafed lupine present higher potential as phytoremediation species than white lupine.

Papaya seedlings irrigation with saline water in soil with bovine biofertilizer

Water used for irrigation in semiarid regions of the world is not always of good quality, and may contain salts levels that inhibit plants growth. This study was conducted to evaluate the growth of papaya ( Carica papaya L.) ‘Golden’ seedlings irrigated with saline water in soil with and without bovine biofertilizer produced by anaerobic fermentation of a mixture of fresh bovine manure and water. The experiment was carried out in Areia County, Paraiba State, Brazil. Treatments were distributed in randomized blocks using a factorial design 5 × 2 relative to five salinity levels in irrigation water of 0.5, 1.0, 2.0, 3.0 and 4.0 dS m-1 in soil with and without bovine biofertilizer, corresponding to 10% of the substrate volume. At 90 d after emergence (DAE), both the electrical conductivity (EC) in soil saturation extract, biometric growth and DM production of papaya seedlings were evaluated. Increased salinity from 0.5 to 4.0 dS m-1 raised, within 90 DAE, soil EC of saturation extract (ECse) from 1.19 to 3.95 dS m-1 and from 1.23 to 3.63 dS m-1 in treatments with and without bovine biofertilizer, respectively. Also, the increase in water salinity from 0.5 dS m-1 to the estimated maximum values ranging from 1.46 to 2.13 dS m-1 stimulated seedling height to 11.42 and 18.72 cm in soil with and without bovine biofertilizer, respectively. Higher salinity levels in irrigation water increased soil salinity levels to values that inhibited both growth and quality of papaya seedlings, but with less severity when treated with bovine biofertilizer.