Decomposition and nitrogen mineralisation of two wild lupins (Leguminosae) species with potential as green manures

The amount of biomass produced by various native species of genus Lupinus (L.) growing in Mexico ranges from 2.9- 8.2 Mg/ha of dry matter, which can add up to 200 kg/ha of N to soil as green manure. However, information is scarce on the decomposition and mineralisation this biomass in the soil. The above-ground decomposition and N mineralisation of Lupinus mexicanus Cerv. ex Lag. and Lupinus rotundiflorus M.E. Jones species from Mexico using fine-mesh litter bags was evaluated. Litter bags containing 5 g of above-ground air-dried biomass at the vegetative and flowering stages were buried at a depth of 20 cm. Were dug up every 3 weeks over the course of 4 months, dried and re-weighed to determine the lost mass and total N by the Kjeldahl method. The largest decrease in residue mass occurred during the first 3 weeks of incubation. However, the lost mass was higher in younger green manure (75 days old) than in older plants (85 days old) after 18 weeks of exposure in the field. It was found that 60-75% of the total N in the plant material was released in the first 6 weeks. In L. rotundiflorus green manure, it was found that 79.14% of the initial N in the vegetative stage and 77.6% of N in the flowering stage was released 18 weeks after litter bag installation, whereas L. mexicanus were 74.6% and 74.7%, respectively. It was found that both decomposition and N mineralisation occurred quickly in the green manures evaluated

Bagazo y composta de bagazo de agave tequilero en suelos contrastantes: 1. Dinámica de degradación: Dinámica de degradación de Bagazo y composta

In the state of Jalisco (Mexico), the tequila industry generates a solid waste called agave bagasse which can be used as an organic amendment. However, its decomposition dynamics in soil is unknown. The objective was to evaluate the degradation process of four materials, Autoclave Bagasse (BA); diffuser bagasse (BD); Compost bagasse autoclave (CBA); and diffused bagasse compost (CBD), incubated in two contrasting soils (Regosol and Luvisol) for one year, to determine the remaining dry mass (MSR); decomposition constant (k); and isohumic coefficient (Ci), using the decomposition bag technique. The MSR showed significant differences between materials and soils, the highest losses occurred in BD and BA 74 and 62% in Regosol and 62 and 47 % in Luvisol. The highest values of k were presented in BD in Regosol (0.0099) and Luvisol (0.0074), followed by BA in Regosol (0.0059) and Luvisol (0.0025). The bagasse presented low values in Ci (0.51 and 0.72 with BA and 0.37 and 0.48 with BD, in Regosol and in Luvisol, respectively). The remaining dry matter and the decomposition constant revealed that the degradation processes of the bagasse were more intense and accelerated than in the compost.En el estado de Jalisco (México), la industria tequilera genera un residuo sólido llamado bagazo de agave el cual puede ser aprovechado como enmienda orgánica. Sin embargo, su dinámica de descomposición en suelo se desconoce. El objetivo fue evaluar el proceso de degradación de cuatro materiales, Bagazo autoclave (BA); Bagazo difusor (BD); Composta bagazo autoclave (CBA); y Composta bagazo difusor (CBD), incubados en dos suelos contrastantes (Regosol y Luvisol) durante un año, para conocer la masa seca remanente (MSR); constante de descomposición (k); y coeficiente isohúmico (Ci), mediante la técnica de bolsas de descomposición. La MSR mostró diferencias significativas entre materiales y suelos, las mayores pérdidas se presentaron en BD y BA 74 y 62 % en Regosol y 62 y 47 % en Luvisol. Los mayores valores de k se presentaron en BD en Regosol (0.0099) y Luvisol (0.0074), seguido del BA en Regosol (0.0059) y Luvisol (0.0025). Los bagazos presentaron valores bajos en Ci (0.51 y 0.72 con BA y 0.37 y 0.48 con BD, en Regosol y en Luvisol, respectivamente). La materia seca remanente y la constante de descomposición revelaron que los procesos de degradación de los bagazos fueron más intensos y acelerados que en las compostas

Soybean meal substitution by dehulled lupine () with enzymes in broiler diets

Objective Evaluate the effects of i) dehulling of lupine seed on chemical composition and apparent metabolizable energy (AME) and ii) soybean meal substitution by dehulled lupine seed in broiler diets with enzymes on productive performance, size of digestive organs and welfare-related variables. Methods Experiment 1, chemical composition and AME were determined in whole and dehulled lupine seed. Experiment 2, two hundred eighty-eight one-day-old male Ross 308 broilers were used. The experimental diets were maize-soybean meal (MS), MS with enzymes (MSE) and maize-dehulled lupine seed with enzymes (MLE). Diets were assigned to the experimental units under a completely randomized design (eight replicates per diet). The body weight (BW) gain, feed intake, feed conversion, digestive organ weights, gait score, latency to lie down and valgus/varus angulation were evaluated. Results The dehulling process increased protein (25.0% to 31.1%), AME (5.9 to 8.8 MJ/kg) and amino acid contents. The BW gain of broilers fed the MLE diet was similar (p>0.05) to that of those fed the MS diet, but lower than that of those fed the MSE diet. Feed intake of broilers fed the MLE diet was higher (p0.05) to those fed the MSE diet. Feed conversion of broilers fed the MLE diet was 8.0% and 8.7% higher (p<0.05) than that of those fed the MS and MSE diets, respectively. Broilers fed the MLE diet had the highest (p<0.05) relative proventriculus and gizzard weights, but had poor welfare-related variables. Conclusion It is possible to substitute soybean meal by dehulled lupine seed with enzymes in broiler diets, obtaining similar BW gains in broilers fed the MLE and MS diets; however, a higher feed intake is required. Additionally, the MLE diet reduced welfare-related variables