Green manure in coffee systems in the region of Zona da Mata, Minas Gerais: characteristics and kinetics of carbon and nitrogen mineralization.

The use of green manure may contribute to reduce soil erosion and increase the soil organic matter content and N availability in coffee plantations in the Zona da Mata, State of Minas Gerais, in Southeastern Brazil. The potential of four legumes (A. pintoi, C. mucunoides, S. aterrimum and S. guianensis)to produce above-ground biomass, accumulate nutrients and mineralize N was studied in two coffee plantations of subsistence farmers under different climate conditions. The biomass production of C. mucunoides was influenced by the shade of the coffee plantation.C. mucunoides tended to mineralize more N than the other legumes due to the low polyphenol content and polyphenol/N ratio. In the first year, the crop establishment of A. pintoi in the area took longer than of the other legumes, resulting in lower biomass production and N2 fixation. In the long term, cellulose was the main factor controlling N mineralization. The biochemical characteristics, nutrient accumulation and biomass production of the legumes were greatly influenced by the altitude and position of the area relative to the sun

Decomposition and nutrient release of leguminous plants in coffee agroforestry systems.

Leguminous plants used as green manure are an important nutrient source for coffee plantations, especially for soils with low nutrient levels. Field experiments were conducted in the Zona da Mata of Minas Gerais State, Brazil to evaluate the decomposition and nutrient release rates of four leguminous species used as green manures (Arachis pintoi, Calopogonium mucunoides, Stizolobium aterrimum and Stylosanthes guianensis) in a coffee agroforestry system under two different climate conditions. The initial N contents in plant residues varied from 25.7 to 37.0 g kg-1 and P from 2.4 to 3.0 g kg-1. The lignin/N, lignin/polyphenol and(lignin+polyphenol)/N ratios were low in all residues studied. Mass loss rates were highest in the first 15 days, when 25 % of the residues were decomposed. From 15 to 30 days, the decomposition rate decreased on both farms. On the farm in Pedra Dourada (PD), the decomposition constant k increased in the order C. mucunoides < S. aterrimum < S. guianensis < A. pintoi. On the farm in Araponga (ARA), there was no difference in the decomposition rate among leguminous plants. The N release rates varied from 0.0036 to 0.0096 d-1. Around 32 % of the total N content in the plant material was released in the first 15 days. In ARA, the N concentration in the S. aterrimum residues was always significantly higher than in the other residues. At the end of 360 days, the N released was 78 % in ARA and 89 % in PD of the initial content. Phosphorus was the most rapidly released nutrient (k values from 0.0165 to 0.0394 d-1). Residue decomposition and nutrient release did not correlate with initial residue chemistry and biochemistry, but differences in climatic conditions between the two study sites modified the decomposition rate constants

The Combined Effect of IgG and Fe Supply and Feeding Management on Growth Rates of Calves on Eight Commercial Dairy Farms in Germany

During the first days of a calf’s life, the foundations are laid for successful growth and thus also for the later performance of the cows. The aim of the present study was to analyze the impact on the weight gain of newborn calves due to important management factors related to colostrum supply, iron supply, feeding regime and microbial load at first feeding. In spring 2017, information of 123 Holstein calves were analyzed with regard to the colostrum supply and management factors on eight commercial dairy farms located in Germany. Additionally, blood samples of newborn calves were analyzed for total immunoglobulin G (IgG) and serum iron content. Furthermore, Brix analysis and analysis of contamination by E. coli were performed on first colostrum samples from teats or buckets. Average daily weight gain of calves at days 14 and 50 was calculated. The colostrum IgG was estimated by Brix refractometer. The volume of initial colostrum supply and the time between birth and colostrum intake significantly (p p < 0.05) on daily weight gains. In conclusion, this study shows that, in addition to a sufficient supply of immunoglobulins, other aspects, such as an adequate colostrum, iron and milk supply, play an essential role in calf growth rates

Structural Reciprocity: Critical Overview and Promising Research/Design Issues

Reciprocity is a structural principle that has fascinated designers and builders throughout the world since ancient times. Despite the topic's having been studied by various academics, designers and researchers, a critical overview of the references is still missing, as is an outline and discussion of the current and future promising research/design issues. Further, no single text provides an exhaustive definition of the principle of structural reciprocity and it must be critically reconstructed from several different sources. This paper aims to fill in these gaps, providing a complete and annotated list of references, in which historical examples, as well as patents, research articles and terminological issues are discussed. A consistent definition of structural reciprocity is also proposed, and the promising developments of such a principle are outlined in order to guide designers and researchers in the futur