Reactive Natural Phosphate Research Articles

Efficiency of phosphate fertilizers containing growth promoters in plant fertilization

Optimizing water and nutrient absorption in plants can be achieved through a practical strategy: the combination of plant growth promoters (PGPs) with phosphate fertilizers. This synergistic approach holds promise for enhancing agricultural productivity and sustainability. The objectives of this work were to produce new phosphate fertilizers containing PGPs and to evaluate the efficiency in promoting the growth of the roots and shoots and increased phosphorus (P) uptake of plants. The fertilizers produced contained reactive natural phosphate rock from Morocco and PGPs indole-3-butyric acid, humic substances or Trichoderma afroharzianum, and a control fertilizer, without adding PGPs. The agronomic efficiency of this fertilizers were evaluated in two contrasting soils. The additional treatment with the monoammonium phosphate was included. The experimental unit consisted of rhyzobox containing 350 cm3 of soil, where a soybean plant was grown. Thirty days after sowing, the root length, average root diameter, root tips, and fine roots were measured using WinRHIZO software. The dry matter and P content of the roots and shoots were determined. PGPs have a great potential to increase the efficiency of P absorption by plants and the photosynthetic rate, and have a great potential to increase phosphorus use efficiency. The effects of PGPs were observed in the architecture of the root system, leaf area, and increased P content by plants. In sandy soil, the application of phosphate rock containing humic substances, Trichoderma afroharzianum, and indole-3-butyric increases the total phosphorus uptake by 26.5%, 16.3%, and 12.2%, respectively.

Efeito residual de fontes de fósforo na presença e ausência de composto orgânico na produção de beterraba e chicória em cultivo sucessivo de brócolis

ABSTRACT The utilization of organic fertilizer for a short cycle crop may allow planting, in sequence, another short cycle crop, without the need for new fertilizers, reducing the costs of a new fertilization. The objective of this study was to evaluate the residual effect of fertilization applied to broccoli with phosphorus sources in the presence and absence of organic compost, on beet and chicory production in subsequent cultivation. In broccoli cultivation, four sources of phosphorus (thermophosphate, natural phosphate, natural reactive phosphate, and triple superphosphate) (600 kg/ha of P2O5) were evaluated in the presence and absence of organic compost (Visafértil®, 55 t/ha) before planting. After the removal of the cultural remains of broccoli, beet and chicory, seedlings were transplanted in the same plots of the first crop treatments. For each species eight treatments were evaluated, in a 4 x 2 factorial scheme. The first factor were the four sources of phosphorus and the second one was the application or not of organic compost before broccoli (hybrid BRO 68) planting. Treatments with organic compost showed greater production of beet and chicory, compared to the absence of compost. Fertilization with organic compost associated to the phosphorus sources provides necessary residual effect to beet and chicory production. The best P source for beet was triple superphosphate, and for chicory, in the absence of organic compost, triple superphosphate was the best source. In the presence of organic compost, the best sources were triple superphosphate and natural phosphate.

DC resistivity and gravimetry to improve analysis and assessment in phosphate exploration: Serra da Bodoquena, Western Mato Grosso do Sul state – Brazil

Phosphatic zones with high exploration potential were identified in the mid-western area near Bonito municipality, Mato Grosso do Sul state, Brazil. This resource consists of a significant matter in reactive natural phosphate production representing an important element to increase agriculture in the country. The present study proposes an unusual geophysical approach as a method to identify and delineate rocks related to P2O5 enrichment in the Ressaca target located in Bonito municipality, Mato Grosso do Sul State, Brazil. DC resistivity and gravimetric methods integrated with detailed surface geologic mapping were applied to detect lithologic heterogeneities near-surface and in-depth. The materials and their respective physical properties are related to weathered alteration zones (supergene) and phosphatic dolomitic breccias associated with the highest phosphatic concentration zones according to previous geologic prospective surveys. The resistivity and gravimetry results along with E-W oriented profiles detected significant anomalies concentrated in a zone in the mid-portion of the acquisition area. Resistivity, Bouguer, and Residual data integration allowed us to define circular features related to the enriched breccias and supergene ore. Results also define a near-surface concentration zone representing a useful tool to assess and help the subsurface analysis leading to an increase in the prospective survey planning (drilling) and the company's budget.

Morphophysiological aspects of bean plants cultivated with natural reactive phosphate and solubilizing and growth promoting microorganisms

Beans (Phaseolus vulgaris L.) are an economically important crop, being part of the daily meal of a large part of the Brazilian population. One of the most common problems in bean cultivation is the low availability and low mobility of phosphorus. Among the strategies to improve the acquisition of phosphorus from the soil, the association of plants with microorganisms that promote growth and/or phosphate solubilizers stands out, since the efficiency of phosphate fertilizers depends directly on the microbial action in their cycle. Thus, the objective of this study was to evaluate physiological, morphological and biochemical characteristics in bean plants cultivated with the presence or absence of reactive natural phosphate associated or not with seed inoculation with different efficient microorganisms. The experiment was carried out in a greenhouse with a completely randomized design, consisting of eight treatments and four replications. The treatments were composed of: i) control, and application of ii) Azospirillum brasilense, iii) Bacillus subtilis and Bacillus megaterium, iv) efficient microorganisms (ME), v) reactive natural phosphate (RNP), vi) RNP + A. brasilense, vii) RNP + Bacillus, and viii) RNP + ME. Gas exchange and material collection to determine height, stem diameter, dry matter, acid phosphatase activity and P content were performed 55 days after sowing. The treatment RNP + A. brasilense and other microorganisms contributed to a higher photosynthetic rate and transpiration in bean plants. The treatments RNP + ME and RNP + Bacillus promoted greater plant height and stem diameter, respectively. The shoot dry matter was higher in the RNP + ME treatment, in relation to the other treatments. Acid phosphatase activity was higher in the area of ​​bean plants exposed to reactive natural phosphate, and in the roots of plants exposed to treatment with species of the genus Bacillus. It was possible to verify that the application of microorganisms with natural phosphate, despite not causing an increase in the P content of the shoot, favored the conditions of growth and production of bean plants.

INTERACTIONS BETWEEN GREEN MANURE AND ROCK PHOSPHATE ON SOIL NUTRIENT CYCLING ON FAMILY FARMS

ABSTRACT Family farming is important for the production of food for human consumption, but it lacks resources to invest in the soil fertility of its crops. The objective of this study was to analyze whether the use of green manures increases soil fertility in terms of the nutrients N, P and K with low environmental risk for family agricultural production. An experiment was set up in the State of Mato Grosso (Brazil), in randomized complete block design, with a 6 x 3 factorial scheme, four replications, corresponding to 6 types of plants and 3 doses of phosphorus. Leguminous green manure plants were: velvet bean, Crotalaria juncea, Crotalaria ochroleuca and dwarf pigeon pea, in addition to plots with pearl millet and weedy fallow control. Rock phosphate (i.e., reactive natural phosphate) was applied as a source of phosphorus at 0, 50 and 100 kg P2O5 ha-1. The species used as green manure were cut in full bloom and the levels of N, P, K and C in plants and soil were determined. Leguminous green manure plants, after mineralization, increased the stocks of N, P and K in the soil. Crotalaria juncea was the one that reached the highest N accumulation in its constitution, being recommended in the intercropping with species with C/N ratio > 30 to minimize risks of contamination with nitrate in the soil. This work concluded that the managements with green manure plants, especially Crotalaria ochroleuca, are recommended and environmentally safe technical alternatives for family farming.

Liming and Fertilization on the Growth of Eucalyptus benthamii and Eucalyptus dunnii in Brazil

The use of mineral fertilizers has shown substantial productivity gains for the vast majority of Eucalyptus forests. The objective of the present work is to evaluate the response of Eucalyptus benthamii and Eucalyptus dunnii at 48 months of age, to different doses of limestone, soluble NPK, and natural phosphates. The experiment was conducted in a plantation located in South Brazil. The experimental design was a randomized block with three replications, and the treatments consisted of combinations of doses of natural phosphate (NP) (0, 400, 600, and 800 kg ha−1 of Gafsa reactive NP P2O5), limestone (0, 3, 5, 6, and 10 Mg ha−1 of dolomitic limestone), and mineral fertilizer–NPK (0, 100, 133, and 167 kg ha−1 of mixed mineral fertilizer 6-30-6). Height and diameter measurements were taken after 48 months. There was a positive response with the increase of NPK fertilizer dose, and the dose where the highest averages were obtained was 167 kg ha−1. The doses of NP had significant effects on the increase of the variables up to 600 kg ha−1, also the averages decreased with the increase of the dosage. For liming, positive results were observed from its absence to the maximum dose, justifying its use in minimum dose in order to supply the necessary amounts of Ca and Mg in the soil. The use of NPK, natural phosphate, and limestone is recommended, causing an increase in the growth of both species of Eucalyptus studied.

Phosphorus Sources Combined with Doses of Organic Compost Increased the Population of Soil Microorganisms and P Level in the Soil and Plant and the Dry Matter of Sugarcane

The aim of the study was to evaluate the effect of P sources and filter cake, enriched or not with biofertilizers and liquid peat, on the microbial population and the soil available P levels and shoot dry matter and P accumulation by sugarcane. The experiment was conducted in a greenhouse in a completely randomized design with factorial arrangement 4 × 3 + 1 and three replications. The treatments consisted in four sources of P: simple superphosphate, triple superphosphate, monoammonium phosphate and reactive natural phosphate combined with three levels of organic compound: without filter cake, decomposed filter cake (30 t ha−1, dry basis) and decomposed filter cake enriched with liquid peat (4 mL kg−1 of filter cake) and biofertilizers (480 mL kg−1 of filter cake) and a control treatment without organic compound and without phosphorus. At 45 and 110 days after planting the total population of bacteria and fungi, phosphate-solubilizing microorganisms and total microorganisms were evaluated. After 60 and 110 days, the soil available P, plants’ P and dry matter and P accumulation were evaluated. The organic compound increased the population of soil microorganism, the soil P levels, the accumulation of P and dry matter by the plants, regardless of the source of P, although the enrichment with biofertilizer and liquid peat did not enhance this effect. In conclusion, the presence of organic compost enhances the effects of phosphate fertilization.

Correção do solo e adubação fosfatada no crescimento e produção de biomassa em mudas de mogno africano

Objetivou-se avaliar o crescimento de mudas de Khaya ivorensis A. Chev. (Mogno africano) cultivadas com e sem calagem em amostras de solo submetido à adubação fosfatada. O estudo foi conduzido em casa de vegetação na Universidade Federal Rural da Amazônia (UFRA) – Campus Capitão Poço/PA e o solo utilizado para compor o substrato foi um Latossolo Amarelo proveniente da camada de 0–20 cm de profundidade. Os tratamentos constituíram-se de cinco doses de fósforo, tendo como fonte o fosfato natural reativo de Arad. O experimento foi montado em delineamento inteiramente casualizado (DIC) em esquema fatorial, sendo duas doses de calcário (0 e 5 g vaso-1) e cinco doses de fósforo (0, 10, 20, 40 e 80 g vaso-1 de P2O5) com 6 repetições, totalizando 60 parcelas experimentais. Cada parcela foi formada por uma muda, cultivada em vasos com capacidade de 12 quilos de solo durante 210 dias. Ao final do experimento foram realizadas avaliações de altura da planta (H), diâmetro do coleto (DC), número de folhas (NF), massa seca da parte aérea (MSPA), massa seca da raiz (MSR) e do índice de qualidade de Dickson (IQD). As mudas responderam positivamente às doses de P2O5 em todas as variáveis avaliadas e não há necessidade de correção do solo ao se utilizar como fonte de P2O5 o Arad. Para a obtenção de mudas de qualidade em condições semelhantes a este experimento, deve ser utilizada a dose 40 g vaso-1 de P2O5.

Ammonium sulfate enhances the effectiveness of reactive natural phosphate for fertilizing tropical grasses

Reactive natural phosphate is a slow and gradual solubilizing fertilizer, which makes it difficult to use in neutral to alkaline soils. Nitrogen fertilizers which acidify the soil may increase the possibility of using this phosphate fertilizer commercially. Two greenhouse experiments were conducted to compare responses of Xaraés palisadegrass (Urochloa brizantha syn. Brachiaria brizantha cv. Xaraés) and Mombasa guineagrass (Megathyrsus maximus syn. Panicum maximum cv. Mombasa), when different combinations of P and N fertilizers were applied during the establishment phase in non-acidic soils or with corrected acidity. The experiments were carried out in a completely randomized design with 3 fertilizer combinations (simple superphosphate plus urea, SSU; natural reactive phosphate plus urea, RPU; and natural reactive phosphate plus ammonium sulfate, RPAS). There was no difference in tiller density, leaf numbers, forage mass, leaf mass and stem mass for either forage on SSU and RPAS treatments but they exceeded those on RPU. Soil pH was lower in soil fertilized with ammonium sulfate than in soil fertilized with urea. Applying natural reactive phosphate plus ammonium sulfate seems as effective as simple superphosphate plus urea in promoting increased growth in tropical grasses on low-P soils. Longer-term and more extensive field studies are needed to determine if these results can be reproduced in the long term, and the level of soil acidification over time.

Eficiência de Fertilizante Organomineral enriquecido com Ácido Cítrico em Milho (Zea Mays L.) cultivado em Casa de Vegetação

Este trabalho teve como objetivo avaliar o efeito do fertilizante organomineral enriquecido com ácido cítrico na acumulação de matéria seca e fósforo (P) em plantas de milho cultivadas em casa de vegetação. Utilizou-se o delineamento em blocos ao acaso, com fatorial 6x3, combinando seis fontes de P (superfosfato triplo, fosfato natural reativo de Bayóvar, superfosfato + cama de aviário, fosfato Bayóvar + cama de aviário, superfosfato + cama de aviário + ácido cítrico, fosfato Bayóvar + cama de aviário + ácido cítrico), três doses de P aplicado (40, 80 e 120 kg ha-1 de P2O5), com quatro repetições. Os fertilizantes organominerais produzidos com superfosfato triplo propiciaram maior acumulação de matéria seca e P na parte aérea de milho, do que os fertilizantes organominerais com fosfato Bayóvar. As plantas que receberam os fertilizantes organominerais com superfosfato apresentaram maior acumulação de biomassa e P na parte aérea que as plantas que receberam apenas superfosfato, sem efeito do ácido cítrico. O ácido cítrico adicionado ao fertilizante organomineral produzido com fosfato de Bayóvar aumentou a acumulação de P na raiz. Conclui-se que a incorporação de matéria orgânica ao fosfato solúvel aumenta o crescimento do milho e que a adição de ácido cítrico aos fertilizantes organominerais produzidos com fosfato natural aumenta a matéria seca de raiz.

Multivariate Behavior of Irrigated Sugarcane with Phosphate Fertilizer and Filter Cake Management: Nutritional State, Biometry, and Agroindustrial Performance

Increases in production and final quality of the sugarcane crop require the search for new management and evaluation techniques within the production system, which can range from water and nutritional management, such as the application of water saving irrigation associated with sources (conventional and alternative) and phosphorus doses combined with the use of a sophisticated mathematical method, such as multivariate analysis. It can explain the variations caused by the application of irrigation and the sources and doses of phosphorus throughout the crop cycle. Due to the complex relationships and interactions of the soil-water-plant-atmosphere system, the use of multivariate analysis is able to indicate the best management options to be used. The experiment was carried out in a dystrophic Red Yellow Latosol, medium texture. The experiment consisted of randomized blocks and three replications in a 3 × 4 × 2 factorial design comprising three sources of phosphorus (triple superphosphate, Bayovar natural reactive phosphate, and Araxa natural phosphate) and different doses (0, 90, 180, and 360 kg of P2O5 ha−1) in the presence and absence of filter cake (7.5 Mg ha−1, dry basis). Irrigation with rescue equipment was applied in a single blade of 80 mm. Biometrics, nutritional status, and agroindustrial performance of sugarcane were evaluated. The principal component analysis evidenced that the phosphate fertilization associated with filter cake is responsible for increases in sugarcane biometrics, specially tillers at 6 months (0.589) and final tillering (0.577); nutritional status of iron (0.349), manganese (0.348), boron (0.347), sulfur (0.332), and phosphorus (0.331); and agroindustrial performance of sucrose (0.476), stalk yield (0.470), and total recoverable sugar (0.439). The water saving irrigation potentiated the use of phosphate fertilizer associated with filter cake, increasing the nutritional status of the plants. However, the correlation was irrelevant and or negative for levels of potassium and calcium. In addition, it favored biometrics and agroindustrial performance by expressing a direct and positive correlation with stalk yield, sucrose, and total recoverable sugar, but an inverse correlation between final tillering and plant height, tons of pol per hectare, and total recoverable sugar.

Reactive Natural Phosphate in Safflower Fertilization in Cerrado Oxisol

Fertilizer management has a direct influence on crop productivity, especially phosphorus, which is most limiting to the development of crops in tropical soils due to the genesis of these soils. In this sense, it is necessary to use nutrient sources that are agronomically efficient at reduced costs compared to conventional sources. Thus, the objective of the present study was to evaluate the effects of reactive natural phosphate as a source of phosphorus on the development, growth, and yield of safflower in Cerrado Oxisol. The experiment was carried out in a greenhouse at the Federal University of Mato Grosso, Campus of Rondonópolis. The completely randomized design consisted of the following treatments: 0, 100, 200, 400 and 600 mg dm-3 of reactive natural phosphate (Bayóvar reactive phosphate), with 6 replicates, consisting by pots with 2 dm3 of capacity. To the Oxisol used to fill the plots was incorporated dolomitic limestone to increase base saturation to60%. Safflower cultivar used was IMA 0213 with a final population of three plants per plot. Plant height, number of leaves and chlorophyll index were evaluated at 15, 30, 45 and 55 days after emergence. In the last evaluation plants were cut and the number and diameter of the chapters, shoot and chapters dry mass, volume and root dry mass were also evaluated. The results were submitted to analysis of variance and regression up to 10% probability. In general, safflower crop shows a positive response to application of reactive natural phosphate. Doses between 389 and 600 mg dm-3 promoted best results for development and safflower production in an Oxisol.

Phosphorus sources associated with organic compound in broccoli production and soil chemical attributes

ABSTRACT Phosphorus is a finite natural resource and the use of gradual-release phosphate sources, associated with an organic compound may favor a more rational use of this nutrient, since organic matter protects P from soil fixation. The aim of this study was to evaluate the effect of phosphorus sources application, associated with organic compound at planting, on single inflorescence type broccoli production and soil chemical properties at the end of the cycle. Eight treatments were evaluated, in a 4 x 2 factorial scheme, using four phosphorus sources [thermophosphate (TM), natural phosphate (NP), reactive natural phosphate (RNP) and triple superphosphate (TSP)]; in the presence (55 t ha-1) and absence of organic compound Visafértil® at planting. The experimental design was randomized blocks, with four replicates. TSP source presented higher P contents. TM source showed, in the absence of organic compound, higher pH and contents of organic matter, Ca, Mg, SB and V%. In the presence of organic compound, NP source provided higher contents of organic matter and K. The addition of organic compound increased pH and resulted in higher contents of P, K, Ca, SB, CEC and V%. The presence of organic compound favored higher productivity for the sources TM, NP and TSP. Among these sources, TSP provided the highest production both in the presence or absence of organic compound, considering that NP source was the only one which did not differ from TSP for inflorescence fresh weight and productivity, both in the presence and in the absence of organic compound. We concluded that TSP and NP are the best P sources, associated with the application of organic compound.

Azospirillum brasilense e fosfato natural reativo no estabelecimento de forrageira tropical

It was evaluated the morphogenic characteristics of the Capim Tamani (Panicum maximum cv. BRS Tamani) established with seeds either inoculated or not with Azospirillum brasilense as a function of phosphate sources (triple superphosphate and bayovar natural reactive phosphate) and increasing doses of nitrogen (0, 75, 150, 300 and 600 kg ha-1) in a completely randomized design, organized in a 2 x 2 x 5 factorial scheme with 4 replications. The inoculation with Azospirillum brasilense promoted an improvement in the use of phosphate fertilizers, reducing the amplitude of responses between them. However, the best performance was observed with the source of higher solubility (triple superphosphate)associated with higher levels of nitrogen fertilization.

Reactive natural phosphate and nitrogen fertilizers in Marandu grass fertilization

This study aimed to identify a nitrogen fertilizer in order to allow the use of reactive natural phosphate (phosphate rock) in the fertilization of Marandu grass (palisade grass cv. Marandu) in a sandy clayey Oxisol with low phosphorus content. The experiment was performed in a plant nursery at the Federal University of Mato Grosso (UFMT), in a completely randomized experimental design, in a split-plot scheme, with eight replications. The plots consisted of six fertilization treatments of the Marandu grass (Brachiaria brizantha cv. Marandu), divided into four treatments applied after liming and two treatments without liming. Treatments in the presence of liming were: single superphosphate and urea, single superphosphate and ammonium sulfate, urea and reactive natural phosphate, reactive natural phosphate and ammonium sulfate. Treatments without liming were: reactive natural phosphate and urea, reactive natural phosphate and ammonium sulfate. For this experiment, three growth times were evaluated. Ammonium sulfate allows the use of reactive natural phosphate in the fertilization of the Marandu grass even after liming, whilst urea does not provide sufficient acidity.

Corrective phosphate application as a practice for reducing oxidative stress and increasing productivity in sugarcane

Corrective phosphate application increases the levels of phosphorus (P) in the surface layer of the soil, stimulates plant root growth and increases the volume of soil exploited for water and nutrient uptake, which may reduce abiotic oxidative stress in sugarcane. The aim of this study was to evaluate the productivity and the response of the antioxidant enzyme system in sugarcane when grown in soil that received corrective phosphate application, using doses and sources of P of varying solubility. The experiment was conducted under field conditions in the southern Forest Zone of the State of Pernambuco, Brazil. The treatments were arranged in a randomised block design, in a (4 × 3) +1 factorial scheme with four replications. The factors consisted of a control (with no phosphate application) and the doses (50, 100, 200 and 300 kg P2O5 ha-1 ) and sources (reactive natural phosphate, triple superphosphate and sugarcane press mud) of P applied during the pre-planting stage of the plant cane cycle. The P content of the leaf tissue was considered adequate, and was not influenced by the phosphate application. Phosphate application at an estimated dose of 150 kg P2O5 ha-1 reduced antioxidant enzyme activity and increased shoot dry matter (SDM) by 25.0% and stalk productivity by 8.5%. Superoxide dismutase (SOD) showed the highest positive correlation coefficient with the other antioxidant enzymes, and a negative correlation with SDM, and can be used to evaluate abiotic stress that promotes reductions in sugarcane productivity.

Adubação do milho com superfosfato triplo em Latossolo Vermelho sob efeito residual de fontes alternativas de fósforo

In variable-charge soils, the use of alternative phosphorus sources may influence further soluble phosphate fertilization. This study aimed to evaluate phosphorus (P) availability for corn plants in response to triple superphosphate fertilization (TSP) in a Typic Hapludox (Oxisol) soil with residual P from alternative sources. The experiment was carried out in a greenhouse under a completely randomized design and 2x4x5 factorial scheme, with four replications. Treatments consisted of five TSP doses (0, 30, 60, 90, and 120 mg dm-3 P), and two sequential corn croppings with and without liming; the area was previously grown with Urochloa spp. and fertilized with precipitated phosphate-1 (PP1), precipitated phosphate-2 (PP2), natural reactive phosphate (NRP), and TSP at 120 mg dm-3. The P from TSP has its dynamics within the soil-plant system and fertilization efficiency in corn crops altered by the residual effect of P from alternative sources and by soil acidity correctives. The residual effects of PP2 and NRP, dry matter yield and P accumulation in corn were higher for TSP doses above 30 mg dm-3, being greater in the first cropping and in limed soils. Yet for PP2 and NRP residual effects, the highest soil availability of P was registered after the two sequential cropping in both acidity conditions, thus showing an enhanced residual effect.

Initial Development of Cowpea Bean Fertilized with Natural Phosphate in the Brazilian Cerrado Soil

Cowpea, string Bean, or Macassar bean [Vigna unguiculata (L.) Walp] presents a short life cycle, low water requirement, develops in soils of low fertility, and has the ability to fix nitrogen from the air. In the Cerrado, the oxisols occupy practically all the flat to soft-wavy areas with little reserve of nutrients for the plants, in general, they are soils with great limitations of fertility. A source of alternative phosphate fertilization is the use of reactive natural phosphates. The reactive natural phosphate of Bayóvar presents intermediate solubility between the sources of soluble phosphates and the natural phosphates. In this context, the objective was to evaluate the initial development of Cowpea beans fertilized with the natural Bayóvar phosphate used for cultivation of the Brazilian Cerrado Oxisol. The experimental design was completely randomized, with six doses of phosphorus (0, 100, 200, 300, 400, 500 mg·dm-3) using natural Bayovar phosphate as a source in four replications. The species used in this study was the legume cowpea bean [Vigna unguiculata (L.) Walp] cultivar Tumucumaque. The treatments were applied using the natural phosphate Bayóvar as a source of phosphorus (29% of P2O5). At 33 DAS (days after sowing), the variable number of leaves of the Cowpea bean was analyzed and at 40 DAS, the variables plant height, SPAD chlorophyll index (Soil Plant Analysis Development) and stem diameter were analyzed. For all variables analyzed there was a significant effect. The initial development of the cowpea bean cultivated in the Brazilian Cerrado Oxisol was significantly influenced by the Bayóvar natural phosphate fertilization with the best phosphorus (P2O5) doses in the range of 200 to 350 mg·

Natural reactive phosphate and poultry litter association on growth of forage grasses in an Amazonian Oxisol

: The interaction of natural reactive phosphate with poultry litter may increase the production of forage grasses as a result of phosphorus (P) uptake. This study’s goal was to analyze growth, production and P concentration of diagnostic leaves of forage grasses fertilized by an Arad reactive phosphate + poultry litter association. The experiment employed a 23 factorial, with the following factors: forage grasses (Urochloa brizantha and Panicum maximum), Arad rates (0 and 50 mg dm-3 P2O5), and poultry litter (0 and 7.5 g dm-3). At the first harvest, the highest dry-matter production of leaves, sheaths + stems and shoots occurred in the interaction P. maximum × Arad × poultry litter. P concentrations in diagnostic leaves as well as number of leaves were similar between forage grasses, but higher in the interaction between Arad + poultry litter when compared to isolated fertilizers. At the second harvest, dry-matter production of shoots and sheaths + stems was higher in the U. brizantha + poultry litter interaction than in other interactions. Compared to the other fertilizers, P concentration in the diagnostic leaves at second harvest was higher in grasses fertilized with poultry litter. At second harvest, the number of leaves and tillers was highest in the U. brizantha + Arad + poultry litter interaction, followed by the Arad + poultry litter interaction. The association of Arad and poultry litter promotes adequate P nutrition and biomass production of forage grasses, and can therefore be considered an important instrument for the establishment of these grasses.

Reactive natural phosphate enriched with filter cake enhances soil P content and noni seedlings growth

ABSTRACTOne of the major challenges in crop production is increase efficiency of non-renewable P sources, or replace them with renewable sources. The objective of this study is to evaluate the effects of phosphorus (P) fertilization using reactive natural phosphate, filter cake, peat and biofertilizer on soil P content, foliar P content and growth of noni seedlings. The treatments were: control (without P fertilization); phosphorus; filter cake; phosphorus + filter cake; phosphorus + filter cake + peat; and phosphorus + filter cake + peat + biofertilizer. All treatments were replicated four times and arranged in a completely randomized design. The treatments phosphorus + filter cake; phosphorus + filter cake + peat; and phosphorus + filter cake + peat + biofertilizer increased phosphorus content in soil and in leaf, and the growth of noni seedlings. Our results indicates that natural reactive phosphate enriched with filter cake can be used as phosphate fertilizer on noni seedlings cultivation.