Alternative Nutrient Sources Research Articles

Alternative nutrient sources for biotechnological use of Sporosarcina pasteurii.

The potential use of Sporosarcina pasteurii in possible biotechnological applications on a large scale (ground improvement, consolidation of building structures and ornamental stone, or in developing bio-materials for the building industry), is based on its ability to produce high amounts of carbonate in a short period of time via urea hydrolysis. Industrial biomass production would have a low environmental impact and would be most economical if the standard growth media could be replaced with alternative nutrient sources, such as byproducts or wastes from other industries, or other low cost ingredients. The use of cost effective ingredients must guarantee ureolytic activities and growth conditions that are comparable to those resulting from the standard nutrient medium. In this work, three types of alternative media were tested for growing the ureolytic active bacteria S. pasteurii: (1) alternative nutrient sources such as industrial wastes resulting from the dairy and brewery industries, (2) fertilizer urea as an alternative urea substitute, and (3) different types of poultry manure based fertilizers as nutrient and urea substitutes. The comparison between the standard media, the nutrient alternatives and urea substitutes was possible by taking the protein concentration and nitrogen content into account. Bacterial activity was evaluated in terms of biomass changes over time (CFU, optical density, ATP measurements) and indirect estimation of the enzyme production (Nessler assay, conductivity measurement). The results revealed that some of the dairy wastes tested, such as whey and buttermilk, are potential alternative nutrients for bacterial development, while the urea fertilizer is perfectly suitable as an economical substitute for pure laboratory grade urea.

Effect of Alternative Nutrient Sources During Anaerobic Degradation of Potato Wastewater

The supplementation of nutrients on biological wastewater treatment in many cases may become a relevant part of the treatment cost. In that sense, the finding of new efficient and economic nutrient sources is very important in large scale industrial applications. This work reports on the effect of four readily available alternative nutrient sources during anaerobic degradation of potato wastewater: Peptone, soybean meal, sludge from an aerobic wastewater treatment plant (aerobic sludge) and NH 4 NO 3 plus Micronutrient Supplementation (MS). The addition of alternative nutrient sources changed the rate limiting step from the last steps to hydrolysis in all the cases. While the added soybean meal allowed obtaining the higher final conversion, the degradation rate was slower than the non-supplemented control. The assays with NH4NO3+MS as nitrogen source presented the highest degradation rate. Moreover both NH4NO3 and MS are needed to improve the degradation rates. The percentage of residual COD after treatment was similar for peptone, aerobic sludge and NH4NO3+MS test. However, the lowest percentage of residual soluble COD was obtained when the aerobic sludge was used as supplement. The aerobic sludge presented Co and Mo deficiencies. Finally, taking into account the advantages and disadvantages discussed, among those tested, the aerobic sludge seems to be the best alternative nutrient source for industrial applications.

EFFECT OF ALTERNATIVE MULTINUTRIENT SOURCES ON SOIL CHEMICAL PROPERTIES

The current high price of potassium chloride and the dependence of Brazil on imported materials to supply the domestic demand call for studies evaluating the efficiency of alternative sources of nutrients. The aim of this work was to evaluate the effect of silicate rock powder and a manganese mining by-product, and secondary materials originated from these two materials, on soil chemical properties and on brachiaria production. This greenhouse experiment was conducted in pots with 5 kg of soil (Latossolo Vermelho-Amarelo distrófico - Oxisol). The alternative nutrient sources were: verdete, verdete treated with NH4OH, phonolite, ultramafic rock, mining waste and the proportion of 75 % of these K fertilizers and 25 % lime. Mixtures containing 25 % of lime were heated at 800 ºC for 1 h. These sources were applied at rates of 0, 150, 300, 450 and 600 kg ha-1 K2O, and incubated for 45 days. The mixtures of heated silicate rocks with lime promoted higher increases in soil pH in decreasing order: ultramafic rock>verdete>phonolite>mining waste. Applying the mining waste-lime mixture increased soil exchangeable K, and available P when ultramafic rock was incorporated. When ultramafic rock was applied, the release of Ca2+ increased significantly. Mining subproduct released the highest amount of Zn2+ and Mn2+ to the soil. The application of alternative sources of K, with variable chemical composition, altered the nutrient availability and soil chemical properties, improving mainly plant development and K plant uptake, and are important nutrient sources.

Implications of widespread algal biofuels production on macronutrient fertilizer supplies: Nutrient demand and evaluation of potential alternate nutrient sources

Biofuels from microalgae are currently the subject of many research projects to determine their feasibility as a replacement for fossil fuels. In order to be a successful candidate, there must be enough fertilizers available to support large scale production. Commercial fertilizers are available for biofuel production from the world fertilizer surplus, but due to nitrogen and phosphorus future production limitations, biofuels would ideally not use any of these resources to be a long term sustainable fuel. Nitrogen, phosphorus and potassium requirements were determined for two algal species, Chlorella and Nannochloropsis, to produce 19 billionl per year (BLPY). At this scale, both algal species would use 32–49%, 32–49% and less than 1% of the world surplus values of nitrogen, phosphorus and potassium, respectively. Nutrient recycling options and alternative sources of nutrients were evaluated to determine their potential contribution of lowering the synthetic fertilizer requirement. Results show that all of the recycling scenarios reduce the nutrient requirements, but catalytic hydrothermal gasification has the largest reduction of 95% of the nitrogen and 90% of the phosphorus. Contributions from all alternative sources can also provide only 5% or less of the required nitrogen when produced in the gulf region. For phosphorus in the same region, poultry concentrated animal feeding operations can provide up to 28% of the requirement of Chlorella. To find the least amount of nitrogen that may be used, catalytic hydrothermal gasification was combined with all of the alternative nutrients available in the gulf region. The maximum amount of biofuels that could be produced in this location without using any synthetic fertilizers is 50±20 BLPY from Chlorella and 45±19 BLPY from Nannochloropsis. This study shows that the nutrient requirement for biofuel production from microalgae will not be a limitation if recycling methods within the process chain and alternative sources of nutrients are utilized.

Dejetos líquidos de suínos como alternativa a adubação mineral na cultura do milho

The use of swine residue (SR) as a source of nutrients in growing crops such as maize, may be an option for disposal of organic waste produced in large quantities in pig farms, allowing total or partial substitution of mineral fertilizer in agricultural crops. The objective of this study was to enable the use of SR as an alternative source of nutrients to the mineral fertilization in maize under conditions of a Rhodic Hapludox. The treatments consisted of the use of mineral fertilizer recommended for maize; no fertilization (control), and doses of SR (25, 50, 75, 100 m³ ha-1). The variables: length and ear diameter, number of grains per spike, thousand grain weight and yield. The highest grain yields were obtained with chemical fertilizers and doses of 50, 75 and 100 m³ ha-1 of SR. The mineral fertilization in maize can be replaced by doses of SR from 50 m³ ha-1, with no loss in productivity of maize in a Rhodic Hapludox with very clayey texture.

South African food allergy consensus document 2014

The prevalence of food allergy is increasing worldwide and is an important cause of anaphylaxis. There are no local South African food allergy guidelines. This document was devised by the Allergy Society of South Africa (ALLSA), the South African Gastroenterology Society (SAGES) and the Association for Dietetics in South Africa (ADSA). Subjects may have reactions to more than one food, and different types and severity of reactions to different foods may coexist in one individual. A detailed history directed at identifying the type and severity of possible reactions is essential for every food allergen under consideration. Skin-prick tests and specific immunoglobulin E (IgE) (ImmunoCAP) tests prove IgE sensitisation rather than clinical reactivity. The magnitude of sensitisation combined with the history may be sufficient to ascribe causality, but where this is not possible an incremental oral food challenge may be required to assess tolerance or clinical allergy. For milder non-IgE-mediated conditions a diagnostic elimination diet may be followed with food re-introduction at home to assess causality. The primary therapy for food allergy is strict avoidance of the offending food/s, taking into account nutritional status and provision of alternative sources of nutrients. Acute management of severe reactions requires prompt intramuscular administration of adrenaline 0.01 mg/kg and basic resuscitation. Adjunctive therapy includes antihistamines, bronchodilators and corticosteroids. Subjects with food allergy require risk assessment and those at increased risk for future severe reactions require the implementation of risk-reduction strategies, including education of the patient, families and all caregivers (including teachers), the provision of a written emergency action plan, a MedicAlert necklace or bracelet and injectable adrenaline (preferably via auto-injector) where necessary.

Effects of Number and Rate of Goat Manure Application on Soil Properties, Growth and Yield of Sweet Maize (Zea mays L. saccharata Strut)

<p>Alternative sources of plant nutrients have now become highly imperative especially for vegetable crop production in Nigeria. Due to the escalating costs, environmental and health problems associated with excessive use of inorganic fertilizers on continuously cropped fields, there is a need for more research on the use of organic manures and residues. A field experiment was conducted in the late growing season from September to December, 2012 in Calabar, a humid forest agroecology in south eastern Nigeria to evaluate the effects of two types of goat manure (GM) application (single and double split doses), five rates of GM (0, 5, 10, 15 and 20 t ha<sup>-1</sup>) and 400kg ha<sup>-1 </sup>NPK fertilizer (120:60:60 kg ha<sup>-1</sup>) rate on soil chemical properties and agronomic performance of sweet maize (<em>Zea mays</em> L. saccharata Strut). Factorial combinations of the treatments were fitted into a randomized complete block design with three replications. The application of GM significantly (P ? 0.05) increased soil pH, organic matter (OM) content, total N, available P, exchangeable K, Ca, Mg and the cation exchange capacity (CEC) status of the soil. Soil exchangeable acidity (EA) was reduced from 1.76 to 0.64 cmol kg<sup>-1</sup> at 20 t ha<sup>-1 </sup>GM rate. The 20 t ha<sup>-1 </sup>also recorded the highest values for soil pH, OM, P, Ca, Mg and CEC, while the values for residual N and K peaked at the NPK fertilizer treatment. The double split application of GM recorded higher values for growth and yield attributes, and increased soil properties than the single application. Growth and yield parameters such as plant height, number of leaves, leaf area index (LAI), total dry matter (TDM), number and weight of grains/ear and total grain yield were significantly (P <span style="text-decoration: underline;"><</span> 0.05) increased by GM and NPK fertilizer treatments. The values obtained for all growth and yield parameters except LAI at the 20 t ha<sup>-1</sup> GM rate were not significantly different from those at the NPK fertilizer treatments. The application of 5, 10, 15 and 20 t ha<sup>-1 </sup>GM, and NPK fertilizer significantly increased TDM by 11.9, 74.3, 91.9, 106.2 and 104.6%; weight of grains/ear by 16.5, 54.6, 61.4, 100.6 and 94.4% and total grain yield by 46.9, 111.7, 121.0, 127.2 and 140.1% respectively, compared with the control treatment. The interactions between number of applications and rates showed that split applying GM at 20 t ha<sup>-1 </sup>maximized TDM, weights of whole and dehusked green ears and total grain yield compared to other GM rates, hence it is recommended.</p>

Sesbania Rostrata as alternative nutrient source for the rice crop .

This study evaluated the effect of using the green manure Sesbania rostrata as a preceding crop on the agricultural yield of rice. The rice was cultivated with two levels of mineral fertilizers (50 and 100% of the economical optimum level of N-P-K). Additionally, the contribution to the nitrogen nutrition of rice from the green manure previously incorporated into the soil was studied in pots using <sup>15</sup>N stable isotope analysis. The results indicated that the Sesbania rostrata incorporation allowed the paddy rice yield to increase by at least 1 Mg ha<sup>-1</sup> and to save 50% of the mineral fertilization employed, during two consecutive harvests. The <sup>15</sup>N isotope analysis showed that although the N accumulation by the crop was significantly stimulated, the green manure N did not contribute directly to the growth of the rice plants, at least during their first cycle. Nevertheless, it is expected that in the medium term, the organic N derived from this green manure would restore the soil mineralized N extracted by the rice crop, thereby balancing the N losses in the system and even improving the soil nitrogen fertility.

Pury, a Fine Powder Made From Silkworm Pupae: Utilization and It’s Effects on Nutritive Value and Organoleptic Quality of Traditional Snack Foods

PURY is a yellowish fine powder made from the silkworm pupae which is a sericultural by-product. It has a well-balanced amount of nutrients (protein and essential amino acids, fats included polyunsaturated fatty acid (PUFA), carbohydrate, vitamins and minerals). The purpose of the study was to utilize and determine the effect of the addition of Pury powder on nutritive value and organoleptic quality of traditional snack foods. The study design was used a randomized block design (RBD) with 3 replications. Organoleptic tests were carried out by 30 semi-trained panellists. There are 4 kinds of snacks based Pury developed i.e. Likury, Sempry, Makary, and Krupy. The result of organoleptic tests showed that the majority of the panellists accepts the product with a brownish-yellow colour, less strong aroma, savoury flavour and crunchy. Statistical analysis of Freadman test showed no significant effect exist of the addition of pury flour to a preference level of product, therefore, the snack based pury is expected to be used as an alternative food source of nutrients and later may support food security and eco-friendly programmes.

Potencial agrícola do uso de resíduo de indústria de carnes em Latossolo Vermelho

A utilização de fontes não renováveis, para a produção de adubos minerais, causa grandes impactos ao meio ambiente. A redução desses impactos é favorecida pela crescente busca por novas fontes nutricionais orgânicas, para as culturas. Este trabalho objetivou avaliar a utilização de resíduo de indústria de carnes (RIC) como fonte alternativa de nutrientes para as culturas do girassol e milho. Foram utilizadas cinco doses de RIC (0 m³ ha-1, 25 m³ ha-1, 50 m³ ha-1, 75 m³ ha-1 e 100 m³ ha-1) e um tratamento com adubação mineral. O RIC proporcionou aumento na produtividade de grãos das culturas de girassol e milho. Na cultura do milho, a máxima produtividade foi obtida com a dose de 87 m³ ha-1 de RIC, equivalendo a 92% da produtividade obtida com a adubação mineral. Na cultura do girassol, doses iguais ou superiores a 20 m³ ha-1 de RIC proporcionaram produtividades iguais ou superiores às obtidas com adubação mineral. O RIC apresentou potencial agrícola para uso como fertilizante orgânico, podendo substituir, parcial ou totalmente, a adubação química.

Cultivation of oleaginous yeast using aqueous fractions derived from hydrothermal pretreatments of biomass

This study addresses some of the current challenges in producing biofuels from yeast oils. Specifically, it valorizes byproduct waste streams of biomass processing technologies by integrating them as alternative carbon or nutrient sources in oleaginous yeast cultivation. Crude glycerol recovered from the thermal hydrolysis of various fats and oils was successfully used in culturing of the oleaginous yeast Cryptococcus curvatus, with growth and lipid accumulation occurring at levels identical to those achieved when commercially purchased glycerol was used. The aqueous byproduct stream from the hydrothermal processing of C. curvatus can also be recycled as a growth substrate for subsequent C. curvatus cultures. The addition of this stream promoted higher biomass production without affecting lipid accumulation and only moderately changing the fatty acid profile. Use of these recycling strategies reduces costs and environmental impact of current microbial biofuels production by providing accessible, non-expensive carbon sources and nutrients for oleaginous yeast cultivation.

Sweet grape mini tomato grown in culture substrates and effluent with nutrient complementation

The objective of this study was to evaluate production of Sweet Grape mini tomato (Lycopersicum esculentum Mill.) using culture substrates and nutrient solution sewage effluent, applied by drip irrigation (fertigation). The experiment was conducted at the University of Goiás State (UEG-UnUCET), from June to November 2011 in Anápolis-GO, Brazil. The experimental design was a 2 x 3 factorial arrangement in a randomized complete block design with four repetitions. The plots were made by combining two nutrient solutions, effluent supplemented with mineral fertilizers (EcS); conventional nutrient solution (SnC); in addition three cultivation substrates: 60% of fine sand washed + 40% substrate composed by 20% coconut fiber plus 80% pine bark (S1); 20% coconut fiber and 80% pine bark (S2) and natural coconut fiber (S3). Sewage effluent were determined nitrate, calcium, potassium, manganese, total phosphate, total iron, magnesium, chloride, sulphate, boron, zinc and molybdenum. We evaluated average mass and average number of fruits per bunch, total fruit and total yield per plant. Statistical difference absence among tested solutions indicates sewage effluent can be used as an alternative source of nutrients in growing mini tomatoes in hydroponics.

Evaluation of the nutritive value of muiumba (Baikiaea plurijuga) seeds: chemical composition, in vitro organic matter digestibility and in vitro gas production.

One of the main constraints hindering the increase of animal production in semi-arid regions of Africa is the inadequate supply of nutrients during the dry season. Incorporation of alternative feed resources in ruminant diets during this period could be a viable approach to overcome these limitations. The objective of this study was to evaluate the nutritive value of muiumba (Baikiaea plurijuga) tree seeds as an alternative nutrient source for ruminants. Muiumba seeds were compared to other eight feedstuffs including two cereal grains (corn and oat), two wheat by-products (wheat bran and distilled wheat) and four protein meals (coconut meal, sunflower meal, soybean meal and rapeseed meal) as to its chemical composition, in vitro organic matter digestibility (IVOMD) and in vitro gas production. The moderate crude protein concentrations (145 g/kg DM) of muiumba seeds indicate that this feedstuff could not be used as a protein supplement, contrarily to the majority of multipurpose tree seeds. Although the starch content was scarce (15 g/kg DM), the low neutral detergent fibre (235 g/kg DM), low molecular weight sugar (76.1 g/kg DM) and non-starch polysaccharide (510.5 g/kg DM) contents indicate that this feedstuff has potential feeding value. This was confirmed by the IVOMD (0.770) and by the data provided by the in vitro gas production showing that muiumba seeds had high (P < 0.05) maximum gas production and fractional fermentation rates, suggesting that these seeds are characterized by a highly fermentable fraction.

Fatores antinutricionais e digestibilidade “in vitro” de folhas de Pereskia aculeata Miller

Humans need amino acids, especially the essential ones, which are obtained from the proteins ingested in the diet. With the rampant growth of the world population, it is necessary to increase the protein supplies, especially those of plant origin, which now play a major role as a food source. Leaves of ora-pro-nobis ( Pereskia aculeata Miller) are a high quality protein source and have been used in the traditional cuisine of Minas Gerais for decades. However, it is important to analyze the anti-nutritional and/or toxic factors to consider the use of the plant leaves as an alternative source of nutrients. This work aimed to study the presence of proteic anti-nutritional factors, such as protease inhibitors and lectins, and to evaluate the “ in vitro ” digestibility throughout Tricine SDS-PAGE of these factors extracted from ora-pro-nobis ( Pereskia aculeata Miller) leaves. The extraction of protease inhibitors and lectins from ora-pro-nobis leaves was performed in phosphate buffer. The partial purification of the fractions presenting activity of trypsin inhibitor and lectins was performed by ammonium sulfate precipitation and gel-filtration chromatography. The “ in vitro ” activity of the fractions with protease inhibitor and lectins, with or without heat treatment in the presence of digestive enzymes, showed that the cooking time of 1 minute was sufficient for protease inhibitors degradation. However, this time was not satisfactory for lectins, which remained resistant even after heating. This work shows that with proper cooking, ora-pro-nobis leaves can be used in the diet as a source of aminoacids.

Influence of Supplementing Pasture-Based Primiparous Holstein-Friesian Dairy Cows with Crude Degummed Canola Oil on Milk Fatty Acid Composition

The quest for alternative sources of healthy nutrients that facilitate the modification of milk without compromising drinking quality is a continuous research endeavour. The objective of the study was to the milk fatty acid composition of pasture-based primiparous Holstein-Friesian dairy cows with crude canola oil (CDCO) with a view to improving the milk quality for beneficial health effects. This study tested the hypothesis that incremental supplementation of grazing primiparous Holstein-Friesian cows with CDCO will alter milk fatty acid composition towards increased total monounsaturates. Comparisons were made between unsupplemented grazing dairy cows and their peers on dietary supplements containing low (25ml/Kg DM), medium (35ml/Kg DM) or high levels (50ml/kg DM) of CDCO in addition to ad libitum grazing access to . There was no significant effect (p&gt;0.05) of CDCO supplementation for eight weeks the proportions of total polyunsaturated fatty acids (tPUFA), omega-3 (ω-3) and omega-6 (ω-6) fatty acids in milk. However, significant impacts of CDCO observed on the proportions of 18:1ω9c, 18:1ω7t, total saturated (tSFA) and total monounsaturated (tMUFA) fatty acids (p&lt;0.005), with a significant increase in the tMUFA/tSFA ratio in cows consuming CDCO. It was concluded that incremental levels of CDCO supplementation can modify the fatty acid composition of milk towards increased monounsaturates without any negative impact on grazing primiparous cows

Microalgae digestate effluent as a growth medium for Tetraselmis sp. in the production of biofuels

This study investigated an alternative nutrient source arising from anaerobically digested Tetraselmis sp. effluent (MDE) as a nutrient feed stock to form a closed loop nutrient system. To determine MDE suitability the following factors were observed: growth, lipid content, and the bacterial diversity. MDE was diluted according to the concentration of NH4+ content (20, 40, 60, 80mg/L) and compared against F/2 medium a standard medium for Tetraselmis sp. The growth rate on the MDE medium was not as rapid as the F/2 medium and the less diluted MDE correlated (R2) with lower total lipid contents (R2, 0.927), additionally acyl carrier proteins (ACP) gene expression rates displayed lower gene expression within MDE treatments. Lastly, higher concentrations of MDE were correlated with a higher bacterial diversity throughout the investigation. The suitability of MDE as a nutrient supplement for the production of Tetraselmis sp. biomass and lipid is feasible.

Chemical characterization of the flour of peel and seed from two papaya cultivars

Papaya is among the currently most important tropical fruits grown in Brazil and in the world. The fruit is mainly consumed fresh although it offers many industrial products. The processing of this fruit, as well as its fresh consumption, results in large amounts of waste, such as peels and seeds. Papaya consumption is one of the causes of significant loss of food value; therefore, new aspects on the use of its waste as by-products, or in the production of food additives, or even the incorporation of its flour in food have aroused great interest because these are products of high nutritional value, and their use may be economically viable. The objective of this study was to produce and characterize peel and seed flours from two papaya cultivars (Havai and Calimosa) for their chemical constituents focusing on possible use in foods. The proximate and mineral composition, titratable acidity, soluble solids, pH, contents of vitamin C, and phenolic compounds were determined. According to the results obtained, the papaya peel and seed flours had high contents of protein and fiber and therefore can be used as alternative sources of nutrients and can also be added in foods avoiding waste and adding value to the fruit.

A national-scale comparison of resource and nutrient demands for algae-based biofuel production by lipid extraction and hydrothermal liquefaction

Algae's high productivity provides potential resource advantages over other fuel crops. However, demand for land, water, and nutrients must be minimized to avoid impacts on food production. We apply our national-scale open-pond, growth, and resource models to assess several biomass to fuel technological pathways based on Chlorella sp. We compare resource demands between hydrothermal liquefaction (HTL) and lipid extraction (LE) to meet 1.89E+10 and 7.95E+10 L yr−1 renewable diesel targets. We estimate nutrient demands where post-fuel biomass is consumed as co-products and recycling by anaerobic digestion (AD) or catalytic hydrothermal gasification (CHG). Sites are prioritized based on fuel value relative to a set of site-specific resource costs. The highest priority sites are located along the Gulf of Mexico coast, but potential sites exist nationwide. Compared to LE, HTL reduces land requirements at least 50%, freshwater consumption at least 33%, and saline groundwater by 85%. Without recycling, nitrogen (N) and phosphorous (P) demand is reduced 44%, but remains significant relative to current U.S. agricultural consumption. The most nutrient-efficient pathways are LE + CHG for N and HTL + CHG for P (by 52%). Resource gains for HTL + CHG are offset by a 284% increase in N consumption relative to LE + CHG (with potential for further recycling). Nutrient recycling is essential to effective use of alternative nutrient sources. While modeling of availability and costs remains, for HTL + CHG at the 7.95E+10 L yr−1 production target, municipal sources can offset up to 20% of N and 49% of P demand and animal manure could potentially satisfy demands.

English

The increasing world population has led into big food and raw material demand, with high pressure on agriculture. In Brazil, potassium fertilizers are mostly imported rising interest on rocks and mining rejects as alternative sources. The objective of this work was to evaluate the effect of crushed rocks over mineral nutrition, yield and efficiency of potash fertilization in rice. The experiment was carried out under greenhouse conditions in pots with 3.7 kg of Oxisol soil samples. The experimental design was completely randomized, in a factorial layout 4 &times; 6, comprising six crushed rocks used as alternative multinutrient fertilizer (breccia, biotite schist, ultramafic, Chapada byproduct, mining byproduct and phlogopite), and four doses based on potassium (0, 200, 400, 600 kg K2O ha-1), with four replications. The concentration and accumulation of potassium, copper, zinc and nickel in rice shoot dry mass were determined. These data were used to evaluate the efficiency index of K-source rocks on fertilization. It was shown that crushed rocks promote alterations in mineral nutrition, grain yield and potassium use efficiency, remarking their potential to be used as alternative fertilizer in rice cropping systems. &nbsp; Key words: Alternative nutrient source, micronutrient, fertilization efficiency, plant nutrition, soil conditioner.

English

The increasing world population has led into big food and raw material demand, with high pressure on agriculture. In Brazil, potassium fertilizers are mostly imported rising interest on rocks and mining rejects as alternative sources. The objective of this work was to evaluate the effect of crushed rocks over mineral nutrition, yield and efficiency of potash fertilization in rice. The experiment was carried out under greenhouse conditions in pots with 3.7 kg of Oxisol soil samples. The experimental design was completely randomized, in a factorial layout 4 × 6, comprising six crushed rocks used as alternative multinutrient fertilizer (breccia, biotite schist, ultramafic, Chapada byproduct, mining byproduct and phlogopite), and four doses based on potassium (0, 200, 400, 600 kg K2O ha-1), with four replications. The concentration and accumulation of potassium, copper, zinc and nickel in rice shoot dry mass were determined. These data were used to evaluate the efficiency index of K-source rocks on fertilization. It was shown that crushed rocks promote alterations in mineral nutrition, grain yield and potassium use efficiency, remarking their potential to be used as alternative fertilizer in rice cropping systems. Key words: Alternative nutrient source, micronutrient, fertilization efficiency, plant nutrition, soil conditioner.