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.

Effect of Nitrogen and Phosphorus Fertilization on the Growth and Yield of Mustard Under Irrigated Conditions in Agra District

The present field experiment was conducted at Agricultural Research Farm of RBS College, Bichpuri Agra, during Rabi season of 2018-19. The soil of the experimental site is Gangetic alluvial. The experimental was laid out in RBD factorial having 3 main treatment (N level) and 4 sub treatments (P2O5 level) with 3 replications. All growth and yield attributing character increase with application of N @ 120 Kg-1 and P2O5 @ 60 kg-1. All the yield components i.e., number of siliquae plant-1, length of siliqua and number of seeds siliqua-1 improved with the increase in the level of nitrogen. Higher value of harvest index was associated with the application of 60 kg P2O5 ha-1. Seed yield increased appreciably with every additional increase in the level of nitrogen. Respectively 26.85 and 40.05 per cent higher seed yield ha-1 was obtained with the application of 80 and 120 kg ha-1 nitrogen as compared to 40 kg ha-1 .

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.

Phosphorus Fertilization Enhances Productivity of Forage Corn (Zea mays L.) Irrigated with Saline Water

Salinity is a major problem affecting crop production in many regions in the world including Morocco. Agricultural practices such as fertilization could be useful to overcome this problem and improve crop productivity. The objective of our study was to evaluate the combined effect of phosphorus fertilization and irrigation water salinity on growth, yield, and stomatal conductance of forage corn (Zea mays L.) cv. “Sy sincerro”. Field experiments were carried out for two years testing four levels of irrigation water salinity (ECw = 0.7; 2, 4, and 6 dS·m−1) and three rates of phosphorus (105, 126, and 150 kg P2O5·ha−1) fertilization conducted in a split-plot design with three replications. The obtained results show that irrigation water salinity had a negative effect on all monitored parameters. For instance, the dry matter yield reduced by an average of 19.3 and 25.1% compared to the control under saline irrigation with an EC value equal to 4 and 6 dS·m−1, respectively. The finding also showed that phosphorus applications tend to increase root weight, root length, stem length, leaf stomatal conductance, grain yield and dry matter yield under salinity conditions. For example, the addition of phosphorus with a rate of 126 and 150 kg P2O5·ha−1 respectively improved dry matter yield by an average of 4 and 9% under low salinity level (ECw = 2 dS·m−1), by 4 and 15% under medium salinity (4 dS·m−1), and by 6 and 8% under a high salinity level (6 dS·m−1). Our finding suggests that supplementary P application could be one of the best practices to reduce the adverse effects of high salinity on growth and development of forage corn.

Unravelling the Role of Rhizosphere Microbiome and Root Traits in Organic Phosphorus Mobilization for Sustainable Phosphorus Fertilization. A Review

Moving toward more sustainable sources for managing phosphorus (P) nutrition in agroecosystems, organic phosphorus (Po) derived from organic inputs and soil is increasingly considered to complement mineral P fertilizer. However, the dynamics of P added by organic input in soil-plant systems is still poorly understood and there is currently no clear information on how the Po composition of these amendments determines P availability through interactions with the soil microbiome and root traits. Here, we review the main mechanisms of rhizosphere microbiome and root traits governing the dynamics of organic input/soil-derived Po pools in the soil-plant system. We discuss the extent to which the major forms of Po derived from organic input/soil can be used by plants and how this could be improved to provide efficient utilization of organic inputs as potential P sources. We provide new insights into how a better understanding of the interactions between Po forms, root traits, and rhizosphere microbiomes can help better manage P fertilization, and discuss recent advances in the mobilization and recovery of Po from organic inputs. We then develop proposed strategies in agroecology that could be used to improve Po utilization, specifically by better linking plant traits and Po forms, and developing new cropping systems allowing more efficient Po recycling.

Nutrient Accumulation Affected by Corn Stover Management Associated with Nitrogen and Phosphorus Fertilization

Bio-ethanol production from corn stover harvest would change nutrient removal, in particular nitrogen (N) and phosphorus (P), affecting nutrient replenishment and corn development under field-grown conditions. This research was developed to investigate whether stover removal had any influence on the amount of N and P fertilizer required for maximum corn production in the United States (US) Midwest in a stover removal scenario. This study was conducted in Lamberton, MN on a Typic Endoaquoll under continuous corn from 2013 to 2015. The treatments included six N rates (0 to 200 kg N ha−1 in 40 kg increments), five P rates (0 to 100 kg P2O5 ha−1 in 25 kg increments), and two residue management strategies (residue removed or incorporated). Residue management was found to have a significant impact on corn response to N and P application. We verified that residue-removed plots yielded more and therefore required more N and P application from fertilizers. Grain yield after residue was removed was greatest with the highest N and P2O5 rates, whereas grain yield after residue was incorporated was greatest with intermediate N and P2O5 rates in 2013 and 2014. In 2015, residue management did not significantly affect grain yield. Grain N and P accumulation followed a similar behavior as that observed for grain yield. In general, residue removal decreased nutrient availability, while in the residue-incorporated treatment, those nutrients were returned. Although the results of the study showed potential for biomass harvest, it also indicated that nitrogen immobilization and nutrient depletion from the soil could be a limiting factor.