Danilo Rheinheimer dos Santos

Bio: Danilo Rheinheimer dos Santos is an academic researcher from Universidade Federal de Santa Maria. The author has contributed to research in topics: Soil water & Sediment. The author has an hindex of 24, co-authored 101 publications receiving 1584 citations.

Fatores que afetam a disponibilidade do fósforo e o manejo da adubação fosfatada em solos sob sistema plantio direto

Abstract: The basic phenomena of phosphorus dynamics in soil is important to define the rate and application manners of phosphates fertilizers. The forms and availability of phosphorus vary with the soil characteristics and properties. In young soils, the calcium phosphates are the main source to organisms. On the other hand, in highly weathered soils the organic phosphorus cycling assumes great importance in the maintenance of the biological bioavailability, although it is insufficient to economical crop productivity. In tropical and subtropical cultivated soils, the soil phosphorus in solution is controlled by phosphorus adsorbed at functional groups of inorganic colloids. The phosphorus diagnosis is made by soils analysis at different methodologies, each one with their advantages and limitations. The decision on adding phosphate and to the rate define is more dependent on the calibration between the value extracted with the crop yield than the extraction method. The elevation of phosphorus availability can be made in corrective or gradual addition. The corrective fertilization is more efficient, and maybe the only alternative, for phosphorus deficiency correction in deeper soil layers. The correction of phosphorus deficiency in deeper layers after the no-tillage system adoption is difficult. The superficial phosphate application in no-tillage seems not to be a good economical alternative and can become an environmental problem. The research must be intensified focusing among others: (a) phosphorus fractions in soil and crop yield; (b) phosphates fertilizers application in no-tillage system; (c) relation of phosphorus availability with exchangeable aluminum and compacted soil layers in soil deep; (d) monitoring of transferred phosphate from soil to aquatic systems.

Effects of micronization on dietary fiber composition, physicochemical properties, phenolic compounds, and antioxidant capacity of grape pomace and its dietary fiber concentrate

Abstract: In this study, the effects of micronization of grape pomace (GP) and fiber concentrate from GP (FC-GP) on dietary fiber fractions, physicochemical properties, phenolic compounds, and antioxidant capacity were evaluated. A factorial design with two independent variables (22) – rotational speed and milling time – was used to determine the best milling conditions to enhance the soluble dietary fiber (SDF) content. Constituents of insoluble dietary fiber, such as cellulose and lignin, were broken down and the content decreased after milling, resulting in increased SDF content, which indicates fiber compound redistribution. Ball milling had a significant effect on reducing the particle size, as evidenced by scanning electron microscopy. Moreover, FT-IR spectra revealed changes in typical absorption bands of polysaccharides. After milling, powder solubility increased and water holding, oil and cation binding capacities decreased. Furthermore, micronization enhanced phenolic compound extraction, mainly catechin and epicatechin, and the antioxidant capacity evaluated by ABTS and ORAC assays. The results obtained indicate that micronization modifies the dietary fiber composition of GP, increasing possibilities for use as a functional ingredient in the food industry.

Soil organic phosphorus forms under different soil management systems and winter crops, in a long term experiment

Abstract: Organic phosphorus (P) is an important source of phosphate for plants both in natural environments and in cultivated soils. Growing plants with high P recycling capacity may increase the importance of organic forms in phosphate availability mainly in undisturbed soils. The aim of this study was to evaluate the effect of long period of cultivation of different winter species under different soil management systems in the distribution of soil organic P forms, in the P content stored into the soil microbial biomass (SMB) and in the acid phosphatase enzyme activity. The experiment was established in 1986 with six winter treatments (blue lupine, hairy vetch, oat, radish, wheat and fallow) implanted in a Rhodic Hapludox in southern Brazil, under no-tillage system (NT) and conventional tillage system (CT). The crops were cultivated with rational use of chemical phosphate fertilizer, according to plant needs and soil type maintaining high levels of soil organic carbon leading to P organic form accumulation. Growing crops during the winter period in highly weathered subtropical soil increases the importance of microbial interactions in the P cycle, especially in the NT, where a large amount of crop residues is annually added to the soil surface, increasing soil organic P level, P content stored into the SMB and acid phosphatase enzyme activity.

Long-term effect of different soil management systems and winter crops on soil acidity and vertical distribution of nutrients in a Brazilian Oxisol

Abstract: “Strategies” to sustain crop productivity by reducing the fertilizer and lime demands must be developed. The use of plant species that use more efficiently the soil nutrients and tillage systems that provide nutrients accumulation in more labile forms are prerequisites for sustainable agroecosystems. This study aimed to evaluate the long period effect of cultivating different winter species under different soil management systems on vertical distribution of soil nutrients and the soil acidity distribution in soil profile. The experiment was established in 1986 with six winter treatments (blue lupine, hairy vetch, oat, radish, wheat and fallow) under conventional tillage (CT) and no-tillage (NT) in a very clayey Rhodic Hapludox in Southern Brazil. As a result of 19 years of no soil disturbance, soil chemical attributes related to soil acidity and the availability of P and K were more favorable to crops growth up to 10 cm in the soil under no-tillage than in the conventional tillage. On other hand, lime applications in low doses on the soil surface were not efficient in neutralizing the aluminum toxicity below 10 cm depth. It shows that repeated use of lime on the soil surface under NT system can be a viable alternative strategy only when soil acidity and aluminum toxicity in subsurface has been previously eliminated using the adequate amount of lime and incorporating it into the arable layer. Moreover, in the conventional tillage system P and K availability were higher below 10 cm depth compared to the no-tillage system. Even after 19 years of no soil disturbance in the NT system the available P content below 10 cm soil layer was lower than the optimal content of available P recommended to cash crops. The reduced surface K application over time was sufficient to gain adequate crop yields and to maintain the optimal content of soil available K in both soil management systems. The effects of soil management systems were predominant on the soil acidity attributes, and no effects of winter cover crops were observed on soil acidity attributes. Black oat and blue lupine were more efficient in P cycling, increasing the soil available P content especially in the surface soil under NT. The lower amount of biomass produced over time when no cover crops were used in the winter period resulted in lower P and K availability in the soil, showing the important role of growing winter species to maintain soil fertility.

Forms of inorganic phosphorus in soil under different long term soil tillage systems and winter crops

Abstract: The cultivation of crops with different capacity of P uptake and use under long-term soil tillage systems can affect the distribution of P cycling and inorganic forms in the soil, as a result of higher or lower use efficiency of P applied in fertilizers. The purpose of this study was to evaluate the effect of long-term cultivation of different winter species under tillage systems on the distribution of inorganic P forms in the soil. In 1986, the experiment was initiated with six winter crops (blue lupin, hairy vetch, oat, oilseed radish, wheat and fallow) on a Rhodic Hapludox in southwestern Parana, under no-tillage (NT) and conventional tillage (CT). The application of phosphate fertilizer in NT rows increased inorganic P in the labile and moderately labile forms, and soil disturbance in CT redistributed the applied P in the deeper layers, increasing the moderately labile P concentration in the subsurface layers. Black oat and blue lupin were the most efficient P-recyclers and under NT, they increased the labile P content in the soil surface layers.

Dissertação de mestrado

Abstract: O presente estudo 3 tem como tema a produção e reprodução da vida de trabalhadores migrantes temporários nordestinos da construção civil que trabalham no Campus central da Universidade Federal de Santa Catarina — UFSC, em Florianópolis/SC. Seu objetivo principal é analisar as condições de vida, trabalho, moradia e escolarização dos trabalhadores diante do crescimento das migrações na atualidade. Na pesquisa empírica foi realizado um trabalho de campo nos canteiros de obras no campus, com o propósito de identificar as empresas que prestam serviço na universidade e também quais as empresas que empregavam maior número de trabalhadores migrantes temporários nordestinos. Na coleta de dados foram realizadas entrevistas semiestruturadas com os trabalhadores migrantes e com as empresas nos canteiros de obras da universidade. A pesquisa de campo envolveu ainda conversas informais com os trabalhadores migrantes, com as empresas e registros fotográficos.

Global meta-analysis of the relationship between soil organic matter and crop yields

Abstract: . Resilient, productive soils are necessary to sustainably intensify agriculture to increase yields while minimizing environmental harm. To conserve and regenerate productive soils, the need to maintain and build soil organic matter (SOM) has received considerable attention. Although SOM is considered key to soil health, its relationship with yield is contested because of local-scale differences in soils, climate, and farming systems. There is a need to quantify this relationship to set a general framework for how soil management could potentially contribute to the goals of sustainable intensification. We developed a quantitative model exploring how SOM relates to crop yield potential of maize and wheat in light of co-varying factors of management, soil type, and climate. We found that yields of these two crops are on average greater with higher concentrations of SOC (soil organic carbon). However, yield increases level off at ∼2 % SOC. Nevertheless, approximately two-thirds of the world's cultivated maize and wheat lands currently have SOC contents of less than 2 %. Using this regression relationship developed from published empirical data, we then estimated how an increase in SOC concentrations up to regionally specific targets could potentially help reduce reliance on nitrogen (N) fertilizer and help close global yield gaps. Potential N fertilizer reductions associated with increasing SOC amount to 7 % and 5 % of global N fertilizer inputs across maize and wheat fields, respectively. Potential yield increases of 10±11 % (mean ± SD) for maize and 23±37 % for wheat amount to 32 % of the projected yield gap for maize and 60 % of that for wheat. Our analysis provides a global-level prediction for relating SOC to crop yields. Further work employing similar approaches to regional and local data, coupled with experimental work to disentangle causative effects of SOC on yield and vice versa, is needed to provide practical prescriptions to incentivize soil management for sustainable intensification.