ÁGUA SALINA E ADUBAÇÃO FOSFATADA NA CULTURA DO AMENDOIM

ÁGUA SALINA E ADUBAÇÃO FOSFATADA NA CULTURA DO AMENDOIM JOSÉ MARCELO DA SILVA GUILHERME1; GEOCLEBER GOMES DE SOUSA2; SAMUEL DE OLIVEIRA SANTOS3; KRISHNA RIBEIRO GOMES4; THALES VINICIUS DE ARAÚJO VIANA5 1 Mestrando pelo programa de pós graduação em engenharia agrícola da Universidade Federal do Ceará, Campus do Pici (Av. Mister Hull, 2977, Pici, 60.021-970, Fortaleza, Ceará, Brasil). E-mail: [email protected] 2Professor Doutor, Instituto de Desenvolvimento Rural, Universidade da Integração Internacional da Lusofonia Afro-Brasileira (Avenida da abolição, 3, Centro, 62.790-000, Redenção, Ceará, Brasil). E-mail: [email protected] 3 Discente no curso de agronomia da Universidade da Integração Internacional da Lusofonia Afro-Brasileira (Avenida da abolição, 3, Centro, 62.790-000, Redenção, Ceará, Brasil). E-mail: [email protected] 4 Pós doutoranda em engenharia agrícola da Universidade Federal do Ceará, Campus do Pici (Av. Mister Hull, 2977, Pici, 60.021-970, Fortaleza, Ceará, Brasil). E-mail: [email protected] 5 Professor Doutor, Departamento de engenharia agrícola da Universidade Federal do Ceará, Campus do Pici, (Av. Mister Hull, 2977, Pici, 60.021-970, Fortaleza, Ceará, Brasil). E-mail: [email protected] 1 RESUMO A adubação fosfata poderá mitigar o estresse salino em plantas de amendoim. Diante deste contexto, o objetivo deste trabalho foi avaliar o uso de água salina em diversos estágios fenológicos na produtividade da cultura do amendoim cultivado sob adubação fosfatada. O experimento foi realizado na área experimental da Unidade de Produção de Mudas Auroras, da Universidade da Integração da Lusofonia Afro-Brasileira, Redenção, CE. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 6x2, com 5 repetições, sendo utilizadas seis estratégias de irrigação com água salina com condutividade elétrica de 4,0 dS m-1 aplicadas em diferentes estágios fenológicos da cultura: estresse salino na fase vegetativa (E1); na fase de florescimento (E2); no aparecimento do ginóforo (E3); na frutificação/formação de vagem (E4); no estágio final da floração (E5); sem estresse salino (E6) e duas doses de fósforo 3,1 e 6,2 g vaso-1, correspondendo a 50% e 100% da dose recomendada. As variáveis analisadas foram: vagens formadas, vagens mal formadas, número total de vagens por planta, comprimento de vagem, diâmetro de vagem, massa de vagens e a produtividade. O uso de água de maior salinidade na fase vegetativa evidencia menor diâmetro de vagem. Palavras-chave: Arachis Hypogaea L.; Estresse Salino; Nutrição de plantas. GUILHERME, J.M.S; SOUSA, G.G; SANTOS, S.O; GOMES, K.R; VIANA, T.V.A. SALINE WATER AND PHOSPHATE FERTILIZATION IN PEANUT CROPS 2 ABSTRACT Phosphate fertilization can mitigate salt stress in peanut plants. In this context, this work aimed to evaluate the use of saline water at different phenological stages in the productivity of peanuts cultivated under phosphorus fertilization. The experiment was carried out in the experimental area of ​​the Aurora Seedling Production Unit, at the University of Integration of Lusofonia Afro-Brasileira, Redenção, CE. The experimental design was completely randomized, in a 6x2 factorial scheme, with 5 replications, using six irrigation strategies with saline water with electrical conductivity of 4.0 dS m-1 applied at different phenological stages of the crop: salt stress in the vegetative phase (E1); in the flowering stage (E2); in the appearance of the gynophore (E3); in fruiting/pod formation (E4); in the final stage of flowering (E5); without salt stress (E6) and two doses of phosphorus 3.1 and 6.2 g pot-1, corresponding to 50% and 100% of the recommended dose. The variables analyzed were formed pods, malformed pods, total number of pods per plant, pod length, pod diameter, pod mass and productivity. The use of water with greater salinity in the vegetative phase shows a smaller pod diameter. Keywords: Arachis hypogaea L., Salt stress, Plant nutrition.

Yield and phosphorus use efficiency of carrot cultivars

Phosphate fertilization is indispensable for carrot cultivation, as it contributes to plant development, formation of marketable roots and higher yields. In this context, the objective of this study was to evaluate the production and nutritional efficiency of carrot cultivars under phosphate fertilization. The experiments were carried out from July to November 2016 and from June to October 2017, at the Rafael Fernandes experimental farm, District of Alagoinha, Mossoró, RN, Brazil. The experimental design was in randomized blocks, in a 4×4 factorial scheme with 4 replicates. The treatments consisted of the combination of carrot cultivars (Brasília, Planalto, Suprema and Nativa) with phosphorus (P) doses (0, 90, 180 and 270 kg ha-1 P2O5). The characteristics analyzed were: P content in the diagnostic leaf, plant dry matter, plant height, marketable and total yields, and the classification of cultivars for efficiency and response to phosphate fertilization. The increments promoted by phosphate fertilization were 64% in plant height, 444% in dry matter and 284% in marketable yield. The maximum marketable yield was obtained with doses from 186.8 to 243.5 kg ha-1, depending on the cultivar. The Native cultivar was classified as more efficient in the use of P.

Crops' Yield and Roots Response to Soil Phosphorus Distribution Resulting From Long-Term Soil and Phosphate Fertilization Management Strategies

We investigated labile P and roots distribution in the soil profile and their effect on phosphorus uptake and soybean and corn yield under different tillage systems and phosphate fertilization managements. In a long-term experiment fertilized with triple superphosphate (TSP) or reactive phosphate rock (RPR), where the fertilizer was band-applied in the crop row or broadcasted under conventional tillage (CT) or no-tillage (NT), we evaluated labile P (Bray-1) and root density distribution in depth, and crop yield, biomass production and P uptake by soybean (16th crop) and corn (17th crop). The soil disturbance in CT promoted more homogeneous soil P distribution while in NT there was a strong gradient in depth, with nutrient accumulation in the fertilizer application zone. In general, the average content of P in the 0–20 cm layer was similar for the two soil management systems and for the two application methods, but higher for TSP in relation to RPR. Root distribution of soybeans in NT and corn in both tillage systems showed a strong relationship with soil P distribution. The production of biomass, P uptake and grain yield of soybean in CT was influenced by phosphate fertilization management and generally presented lower performance than in NT, what did not occur for corn possibly due to a better P uptake efficiency compared to that of soybean. Greater stratification on the distribution of soil P and soybean and corn roots in NT did not represent any limitation on the nutrient uptake and yield of these crops, not even in the extreme case where the fertilizer was continuously broadcast on the soil surface. The influence of soil tillage management and phosphate fertilization was more evident in soybeans than corn.

DESENVOLVIMENTO INICIAL DE MUDAS DE GUANANDI SUBMETIDAS A DOIS NÍVEIS DE LENÇOL FREÁTICO E DOSES CRESCENTES DE FÓSFORO

DESENVOLVIMENTO INICIAL DE MUDAS DE GUANANDI SUBMETIDAS A DOIS NÍVEIS DE LENÇOL FREÁTICO E DOSES CRESCENTES DE FÓSFORO1 RENATA DA SILVA CUBA DE CARVALHO2; MARA RÚBIA MENDES DE MELO3; fRANCIELLY GUIEIRO GOMES DE SOUSA4; antonio evaldo klar5 1Trabalho originado da tese de doutorado do primeiro autor intitulada: “Cultivo de pimentão em sistema hidropônico com água de reúso em diferentes níveis de disponibilidade de água no substrato”. 2Doutora, Programa de Pós-graduação em Agronomia – Irrigação e Drenagem, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (UNESP), Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu-SP, Brasil, [email protected]. 3Doutoranda, Programa de Pós- graduação em Agronomia, Departamento de Produção e Melhoramento Vegetal. Faculdade de Ciências Agronômica, Universidade Estadual Paulista (UNESP), Rua José Barbosa de Barros, 1780. CEP: 18.610-307, Botucatu-SP - Brasil. E-mail: [email protected]. 4Doutora, Programa de Pós- graduação em Agronomia – Irrigação e Drenagem, Faculdade de Ciências Agronômica, Universidade Estadual Paulista (UNESP), Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu-SP, [email protected]. 5 Professor Emérito do Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (UNESP), Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu-SP, Brasil. E-mail: [email protected]. 1 RESUMO O guanandi é uma espécie nativa com potencial para reflorestamento, porém com poucos resultados na literatura sobre seu cultivo. Diante disto, objetivou-se avaliar o desenvolvimento inicial de mudas de guanandi submetidas a dois níveis de disponibilidade de água no solo e doses crescentes de fósforo. O cultivo foi realizado de fevereiro a junho de 2016, utilizando-se dez lisímetros de lençol freático constante, simulando duas alturas do lençol freático, 0,40 m e 0,70 m. Em cada lisímetro, foram colocados seis vasos contendo uma muda por vaso. As doses de fósforo foram de 0, 40, 80, 120 e 160 mg dm-3 de solo. O delineamento experimental adotado foi em fatorial 2 x 5, com seis repetições, considerando cada vaso uma unidade amostral, totalizando 60. Os parâmetros avaliados foram: altura e diâmetro final, massa fresca da parte aérea, raízes e total, teor relativo, potencial de água na folha (Ψf) e consumo de água. Os resultados permitem inferir que, nas condições avaliadas, a dose de 160 mg dm-3 de fósforo associada ao fornecimento de 537,2 mm de água nos primeiros cinco meses de implantação da cultura, proporciona melhor desenvolvimento morfológico e fisiológico. Palavras chaves: irrigação, lisímetro, adubação fosfatada. CARVALHO, R. S. C.; MELO, M. R. M.; GOMES, F. G.; KLAR, A. E. INITIAL DEVELOPMENT OF GUANANDI SEEDLINGS SUBJECTED TO TWO LEVELS OF WATER TABLE AND INCREASING DOSES OF PHOSPHORUS 2 ABSTRACT The guanandi is a native species with potential for reforestation, but with few results in the literature about its cultivation. Because of this, the objective was to evaluate the initial development of guanandi seedlings subjected to two levels of water availability in the soil and crescent phosphorus dosages. The cultivation was conducted from February to June 2016 by using ten lysimeters of constant water table, simulating two heights of the water table, 0.40 m and 0.70 m. In each lysimeter, one of them, six pots were placed, with one seedling by pot. The crescent phosphorus dosages used were 0, 40, 80, 120, and 160 mg dm-1 of soil. The experimental design adopted was the factorial 2 x 5, with six replications, in which each, pot was considered a plot, totalizing 60 of them. The evaluated parameters were final height and diameter, aerial parts fresh mass, root fresh mass, total fresh mass, relative water level, water potential in the leaf (Ψf), and consumption of water. The results allow us to infer that, under the conditions evaluated, the dosage of 160 mg dm-3 of phosphorus associated with the supply of 537.2 mm of water in the first five months of crop implantation provides better morphological and physiological development, under the conditions evaluated. Keywords: irrigation, lysimeter, phosphate fertilization.

Mycorrhizal fungi and phosphate fertilization in the production of Euterpe edulis seedlings

The present study evaluated the effect of arbuscular mycorrhizal fungi (AMF) inoculation on growth and nutrition of Euterpe edulis seedlings, supplemented or not with phosphate fertilization. The experiment was conducted in a greenhouse. The randomized block design, consisted of a 3x2 factorial arrangement and 4 replicates, with two phosphorus doses (0 and 50 mg dm-3 of soil), two microbiological treatments (Rhizophagus clarus; laroideoglomus etunicatum; R. clarus + C. etunicatum) and control (without fungus). Sowing and inoculation occurred concurrently in 2 kg plastic bags. Height, collar diameter, leaf area, dry shoot mass, macronutrient content and mycorrhizal colonization percentage were determined after 226 days. Regarding mycorrhizal colonization percentage, R. clarus resulted significantly beneficial for the production of E. edulis seedlings. In the absence of phosphate fertilization, R. clarus and mixed inoculum increased all biometric variables and macronutrient contents in seedlings. Therefore, it is concluded that AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy. Highlights: Rhizophagus clarus resulted significantly beneficial for the production of E. edulis seedlings and in the absence of phosphate fertilization, and mixed inoculum ( clarus + Claroideoglomus etunicatum) increased all biometric variables and macronutrient contents in seedlings. The AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy. The AMF, a biological agent of mutualistic associations with plants, constitutes an innovative approach to sustainable agriculture, contributing to increase plant survival rate, a key-factor for the successful reintroduction and conservation of E. edulis, as well as for its commercial exploitation.

UROCHLOA GRASS GROWTH AS A FUNCTION OF NITROGEN AND PHOSPHORUS FERTILIZATION

The urochloa grass (Urochloa mosambicensis) is a perennial grass, C4 plant, with a high photosynthetic rate and CO2 fixation, persistent to water deficit, adapted to a wide diversity of soils and hot climate regions. Thus, the objective was to evaluate the urochloa grass growth and define the best models to estimate plant height as a function of nitrogen and phosphate fertilization. The experimental design was completely randomized, in the 2 x 2 factorial design (presence and absence of nitrogen presence and absence of phosphorus), with four replications. Was used a dose of nitrogen and phosphorus equivalent to 100 kg.ha-1 of N and 150 kg.ha-1 of P2O5, respectively. The following models were used: linear, power, gamma andlogistic to estimate plant height as a function of the following explanatory variables: days after planting, nitrogen and phosphorus doses. The criteria used to determine the best model(s) were as follows: higher adjusted coefficient of determination, lower Akaike information criterion, lower sum of square of residuals and high Willmott index. The plant height in the absence of nitrogen and phosphorus and when applied 100 kg.ha-1 of N and 150 kg.ha-1 of P2O5 was estimated more accurately by the Gamma model with high power of explanation. The adoption of the Gamma model allows to estimate the U. mosambicensis plant height, in a non-destructive manner, with high precision, speed and low cost, depending of age plant and nitrogen and phosphate fertilization.

Phosphate fertilization regulates arbuscular mycorrhizal symbiosis in roots of soybean (Glycine max L.) cultivars in a humid tropical soil

<p>The effect of phosphate fertilization on arbuscular mycorhizal symbiosis and grain yields of soybean cultivars was investigated on P deficient soil. A two-year field study (2017-2018) consisting of two soybean cultivars (TGx 1448-2E and TGx 1440-1E) and three phosphate rates [0, 20 and 40 kg P₂O₅ ha^-1) was laid out in a randomized complete block design with three replications. The results showed that P fertilization significantly (<em>p</em> &lt; 0.001) reduced AMF root colonization of both cultivars in the two cropping years. The arbuscular, vesicular, internal hyphae and total colonization in the root cortex of the soybean cultivars were significantly (<em>p</em> &lt; 0.001) reduced with high P (40 kg) application. However, moderate P (20 kg) promote AMF symbiosis in roots of ‘TG x 1448-2E‘. Dry mass (root and shoot), P uptake and grain yield of the soybean cultivars were significantly (<em>p</em> &lt; 0.001) increased with increasing P ferilization. There was a strong linear relationships between root colonization and total dry matter mass (r = 0.81), P uptake (r = 0.81) and grain yield (r = 0.85). Thus, it could be concluded that moderate P fertilizer application is needed to promote mycorrhizal symbiosis in soybean and sustainable crop production in humid tropical soil.</p>

Growth and mineral composition of Jatropha curcasL.under phosphate fertilization and soil compaction

The present work aimed to quantify the growth of young physic nut plants submitted to variations in phosphorus (P) and specific masses of a Red Yellow Latosol soil. Previously, a soil sample was collected in the 20 to 40 cm layer, making sure in the laboratory the low availability of P - 1.4 mg dm-3 - to apply the treatments of interest. Doses of 0, 106 and 318 mg dm-3 of P were applied, using the simple superphosphate source; and the soils were compacted until reaching specific soil masses equal to 1.53; 1.72 and 1.91 kg dm-3, in a complete factorial scheme, totaling nine treatments. The cultivation was carried out in pots and the dry biomass of the aerial part of the physic nut and its parts fractionated in the stem, leaves adhered to the stem and senescent leaves were determined. The contents of P, K, Ca, Mg, Cu, Fe, Mn and Zn were determined, and from the dry mass accumulation data, the contents of these minerals in the plants were quantified. The statistical analysis of the data consisted of analysis of variance, Tukey average test and regression analysis. In general, the mineral composition characteristics of the plants showed a more pronounced response to phosphate fertilization compared to the tested physical compression. The maximum estimated mineral content in physic nut plants was 51.78 mg of P; 463.37 mg of K; 201.84 mg of Ca; 124.18 mg of Mg; 76.17 µg of Cu; 4,254.07 µg of Fe; 18,787.15 µg of Mn and 769,97 µg of Zn.