Electrical conductivity of complete and commercial nutrient solutions in tube-based passion fruit seedling production / Condutividades elétricas de solução nutritiva completa em comparação com solução nutritiva usada comercialmente na produção de mudas

Fertigation is widely used in seedling production for different crops, including passion fruit. There is no consensus on the ideal nutrient solution, and as such, nurseries have used fertigation empirically. This study assessed the electrical conductivity of nutrient solution containing macro and micronutrients in passion fruit seedling production and compared it with commercially used fertigation. A completely randomized design was used, with five treatments and six repetitions. Four electrical conductivities (0.5, 1.0, 2.0 and 4.0 dS m-1) of a complete nutrient solution and an additional treatment (commercial nutrient solution) were analyzed. Daily fertigation with a complete nutrient solution (macro and micronutrients) at electrical conductivities between 2.6 and 3.3 dS m-1 followed by two daily irrigations are efficient at producing FB 300 "Araguari" passion fruit seedlings in coconut fiber substrate, with benefits such as greater biomass and better Dickson quality index when compared to commercial nutrient solution.

A fertirrigação é amplamente utilizada na produção de mudas de várias culturas, inclusive o maracujazeiro. Não existe consenso sobre qual solução nutritiva deve ser adotada na produção de mudas de maracujazeiro, mas por causa disso, viveiristas têm usado a fertirrigação empiricamente. O objetivo deste trabalho foi avaliar condutividades elétricas de solução nutritiva com macros e micronutrientes na produção de mudas de maracujazeiro e compará-las com uma fertirrigação adotada comercialmente. Foi utilizado delineamento experimental inteiramente casualizado, com cinco tratamentos e seis repetições. Foram estudadas quatro condutividades elétricas (0,5; 1,0; 2,0 e 4,0 dS m-1) de solução nutritiva completa e um tratamento adicional (solução nutritiva adotada comercialmente). Em substrato à base de fibra de coco, fertirrigações diárias com solução nutritiva completa (macro e micronutrientes), com condutividades elétricas entre 2,6 a 3,3 dS m-1, seguidas de duas irrigações diárias são eficientes na produção de mudas de maracujazeiro FB 300 "Araguari", inclusive com vantagens, como maior biomassa e índice de qualidade de Dickson em relação à solução nutritiva comercial.

Nanosilica enhances morphogenic and chemical parameters of Megathyrsus maximus grass under conditions of phosphorus deficiency and excess stress in different soils.

Phosphorus (P) imbalances are a recurring issue in cultivated soils with pastures across diverse regions. In addition to P deficiency, the prevalence of excess P in soil has escalated, resulting in damage to pasture yield. In response to this reality, there is a need for well-considered strategies, such as the application of silicon (Si), a known element for alleviating plant stress. However, the influence of Si on the morphogenetic and chemical attributes of forage grasses grown in various soils remains uncertain. Consequently, this study aimed to assess the impact of P deficiency and excess on morphogenetic and chemical parameters, as well as digestibility, in Zuri guinea grass cultivated in Oxisol and Entisol soils. It also sought to determine whether fertigation with nanosilica could mitigate the detrimental effects of these nutritional stresses. Results revealed that P deficiency led to a reduction in tiller numbers and grass protein content, along with an increase in lignin content. Conversely, P excess resulted in higher proportions of dead material and lignin, a reduced mass leaf: stem ratio in plants, and a decrease in dry matter (DM) yield. Fertigation with Si improved tillering and protein content in deficient plants. In the case of P excess, Si reduced tiller mortality and lignin content, increased the mass leaf:stem ratio, and enhanced DM yield. This approach also increased yields in plants with sufficient P levels without affecting grass digestibility. Thus, Si utilization holds promise for enhancing the growth and chemical characteristics of forage grasses under P stress and optimizing yield in well-nourished, adapted plants, promoting more sustainable pasture yields.

Vinasse as a substrate for inoculant culture and soil fertigation: Advancing the circular and green economy.

Vinasse is a by-product with a key role in circular economy. In this work, we analyze sugarcane vinasse as culture medium for obtaining single and mixed inoculants. Trichoderma harzianum MT2 was cultured in single and sequential co-culture with Pseudomonas capeferrum WCS358 or Rhizobium sp. N21.2. Fungal biomass in single culture was more than three folds higher in vinasse than in a standard medium, and was higher in co-culture with Rhizobium sp. N21.2 than with P. capeferrum WCS358. Bacterial growths in vinasse, in particular P. capeferrum WCS358, were improved in co-culture with T. harzianum MT2. Residual vinasses, obtained after microbial growth, presented almost neutral pH and lower conductivities and toxicity than raw vinasse. Fertigation with residual vinasses modifies characteristics of soil evidenced in the total N, cation exchange capacity, urease and acid phosphatase, and microbial metabolic diversity, in comparison to raw vinasse. In general, soil fertigation with residual vinasse from co-culture with P. capeferrum WCS358 is more similar to irrigation with water. Treatment evaluation indicates that vinasse is suitable for the production of mixed inoculants containing T. harzianum. The co-culture with P. capeferrum WCS358 improves the characteristics of the residual vinasse allowing a fertigation with less detrimental effect in soil in comparison to Rhizobium sp. N21.2. Obtaining valuable biomass of single or mixed inoculants in vinasse with lower ecological impact is relevant for the circular and green economy.

New approaches to the effects of Si on sugarcane ratoon under irrigation in Quartzipsamments, Eutrophic Red Oxisol, and Dystrophic Red Oxisol.

BACKGROUND: C:N:P homeostasis in plants guarantees optimal levels of these nutrients in plant metabolism. H However, one of the causes to the effects of deficit irrigation is the loss of C:N:P homeostasis in leaves and stems that causes reduction in the growth of sugarcane. Being able to measure the impact of water deficit on C:N:P homeostasis in plants from the stoichiometric ratios of the concentrations of these nutrients in leaves and stems. This loss causes a decrease in nutritional efficiency, but can be mitigated with the use of silicon. Silicon favors the homeostasis of these nutrients and crop productivity. The magnitude of this benefit depends on the absorption of Si by the plant and Si availability in the soil, which varies with the type of soil used. Thus, this study aims to evaluate whether the application of Si via fertigation is efficient in increasing the absorption of Si and whether it is capable of modifying the homeostatic balance of C:N:P of the plant, causing an increase in nutritional efficiency and consequently in the production of biomass in leaves and stems of sugarcane ratoon cultivated with deficient and adequate irrigations in different tropical soils. RESULTS: Water deficit caused biological losses in concentrations and accumulation of C, N, and P, and reduced the nutrient use efficiency and biomass production of sugarcane plants cultivated in three tropical soils due to disturbances in the stoichiometric homeostasis of C:N:P. The application of Si increased the concentration and accumulation of Si, C, N, and P and their use efficiency and reduced the biological damage caused by water deficit due to the modification of homeostatic balance of C:N:P by ensuring sustainability of the production of sugarcane biomass in tropical soils. However, the intensity of attenuation of such deleterious effects stood out in plants cultivated in Eutrophic Red Oxisols. Si contributed biologically by improving the performance of sugarcane ratoon with an adequate irrigation due to the optimization of stoichiometric ratios of C:N:P; increased the accumulation and the use efficiency of C, N, and P, and promoted production gains in biomass of sugarcane in three tropical soils. CONCLUSION: Our study shows that fertigation with Si can mitigate the deleterious effects of deficient irrigation or potentiate the beneficial effects using an adequate irrigation system due to the induction of a new stoichiometric homeostasis of C:N:P, which in turn improves the nutritional efficiency of sugarcane cultivated in tropical soils.

What is the optimal fertigation start time and frequency in lettuce seedlings?

Although lettuce is one of the most important vegetable crops cultivated in Brazil, producers conduct seedling production empirically, as there are no published reports on the optimal start time and management strategy for seedling fertigation. The present aimed to assess the influence of fertigation management on the growth, physiological aspects and nutritional status of lettuce seedlings and to determine the optimal fertigation start time and frequency. Two experiments were conducted, each with a randomized block design and six repetitions. The first consisted of six treatments, namely six fertigation start times at 0, 3, 6, 9, 12, and 15 d after emergence (DAE), and the second consisted of five treatments, representing different application frequencies at 3, 4, 5, 6, and 7 d intervals. The assessment of nutrient accumulation levels and biometric and physiological characteristics of the seedlings were performed after transplanting. Fertigation start times significantly affected 14 of the 18 variables assessed, particularly the number of leaves, shoot dry weight, leaf area, initial chlorophyll fluorescence, and P, K, Ca, Mg, and S accumulation. The best results for ten variables were obtained when fertigation began at emergence, with values 17.77 - 35.63% higher than those at fertigation onset at 15 DAE. Application frequency only influenced chlorophyll content and N, P, K, and S accumulation, with optimal results obtained at 3 - 6 d intervals. Beginning fertigation at plant emergence favors dry weight production, nutrition and photosynthesis and shortens the production time of lettuce seedlings. The optimal start time for lettuce seedling fertigation is at emergence, with application performed every 6 d.

Agave angustifolia bulbil growth in different substrates, with doses of fertigation and inoculation with Azospirillum brasilense / Crescimento de bulbos de Agave angustifolia em diferentes substratos, com doses de fertirrigação e inoculação com Azospirillum brasilense

ABSTRACT: There is little information about the production of agave plants in the nursery, so this research assessed the growth in the nursery of Agave angustifolia plants originating from inflorescence bulbils, subjected to different substrates, fertigation doses, and inoculation with Azospirillum brasilense. The bulbils were established for two months in a 50% peat-50% perlite substrate. One hundred and eighty plants were individually transferred to 3.8 dm3 pots for evaluation in an experiment with three factors: 1) type of irrigation: 1.1) water, or 1.2) fertigation with Steiner's nutrient solution (NS), NS-50%, or 1.3) NS-100%; 2) inoculation with Azospirillum brasilense, 2.1) inoculated plants, 2.2) non-inoculated plants; 3) substrate, mixtures of bovine manure (BM) + sand (S) in different proportions, Mix1: 75% BM + 25% S; Mix2: 25% BM + 75% S; Mix3: 50% BM + 50% S. Morphological characteristics were quantified for one year. The largest plants were those that were in substrates with 50% BM, and were fertirrigated with NS-100% and inoculated with Azospirillum brasiliense. The smallest plants were those established a in a substrate with the lowest manure content, irrigated with only water and without inoculation, which was respectively 71.6 and 54.10 cm high, 21 and 15.6 leaves, 76.6 and 62.2 mm in stem diameter, 84.4 and 59.8 cm in rosette diameter.

RESUMO: Existem poucas informações sobre a produção de agave em viveiro, portanto o objetivo deste trabalho foi avaliar o crescimento em viveiro de Agave angustifolia provenientes de bulbilhos de inflorescência, submetidos a diferentes substratos, doses de fertirrigação e inoculação com Azospirillum brasilense. Os bulbilhos foram estabelecidos por dois meses em substrato 50% turfa-50% perlita. Cento e oitenta plantas foram transferidas individualmente para vasos de 3,8 dm3 para avaliação em um experimento com três fatores: 1) tipo de irrigação: 1.1) água ou 1.2) fertirrigação com solução nutritiva de Steiner (NS), NS-50% ou 1.3 ) NS-100%; 2) inoculação com Azospirillum brasilense, 2.1) plantas inoculadas, 2.2) plantas não inoculadas; 3) substrato, misturas de esterco bovino (BM) + areia (S) em diferentes proporções, Mix1: 75% BM + 25% S; Mix2: 25% BM + 75% S; Mix3: 50% BM + 50% S. As características morfológicas foram quantificadas por um ano. As maiores plantas foram aquelas que estavam em substrato com 50% de BM, foram fertirrigadas com NS-100% e inoculadas com Azospirillum brasiliense, enquanto as menores foram aquelas estabelecidas em substrato com menor quantidade de esterco, irrigado apenas com água e sem inoculação, que tinham respectivamente, 71,6 e 54,10 cm de altura, 21 e 15,6 folhas, 76,6 e 62,2 mm de diâmetro do caule, 84,4 e 59,8 cm de diâmetro de roseta.

NO 3 -, K +, and chlorophyll index in fertigated grapevines in the semi-arid region of Brazil

Evaluating the effects of N and K supply on grapevines ( Vitis vinifera L.) and the techniques for nutritional diagnosis is of great importance for fertigation management of this crop. This study evaluated the effects of N and K fertigation on the soluble concentrations of NO 3 - and K + in the petiole sap and on the leaf chlorophyll index in drip irrigated 'Syrah' grapevine (from 17 June 2013 to 25 Nov 2014). The treatments consisted of five levels of N (0, 15, 30, 60 and 120 kg ha -1 ) and K 2 O (0, 15, 30, 60 and 120 kg ha -1 ), combined in an incomplete 5 2 factorial scheme in 13 combinations and arranged in randomized blocks with four replications. We determined NO 3 - and K + concentrations in petiole sap, leaf chlorophyll index, grapevine cluster mass and number per plant, mean grapevine cluster mass, and phenolic composition. High NO 3 - concentrations contributed positively to grapevine yield; however, increased K+ concentrations caused a negative response of sap. For 120 kg N ha -1 rate, NO 3 - in the sap and chlorophyll index showed higher values at the flowering stage, while high values for K + were observed during the grape-ripening stage.(AU)

Agave angustifolia bulbil growth in different substrates, with doses of fertigation and inoculation with Azospirillum brasilense / Crescimento de bulbos de Agave angustifolia em diferentes substratos, com doses de fertirrigação e inoculação com Azospirillum brasilense

There is little information about the production of agave plants in the nursery, so this research assessed the growth in the nursery of Agave angustifolia plants originating from inflorescence bulbils, subjected to different substrates, fertigation doses, and inoculation with Azospirillum brasilense. The bulbils were established for two months in a 50% peat-50% perlite substrate. One hundred and eighty plants were individually transferred to 3.8 dm3 pots for evaluation in an experiment with three factors: 1) type of irrigation: 1.1) water, or 1.2) fertigation with Steiner's nutrient solution (NS), NS-50%, or 1.3) NS-100%; 2) inoculation with Azospirillum brasilense, 2.1) inoculated plants, 2.2) non-inoculated plants; 3) substrate, mixtures of bovine manure (BM) + sand (S) in different proportions, Mix1: 75% BM + 25% S; Mix2: 25% BM + 75% S; Mix3: 50% BM + 50% S. Morphological characteristics were quantified for one year. The largest plants were those that were in substrates with 50% BM, and were fertirrigated with NS-100% and inoculated with Azospirillum brasiliense. The smallest plants were those established a in a substrate with the lowest manure content, irrigated with only water and without inoculation, which was respectively 71.6 and 54.10 cm high, 21 and 15.6 leaves, 76.6 and 62.2 mm in stem diameter, 84.4 and 59.8 cm in rosette diameter.

Existem poucas informações sobre a produção de agave em viveiro, portanto o objetivo deste trabalho foi avaliar o crescimento em viveiro de Agave angustifolia provenientes de bulbilhos de inflorescência, submetidos a diferentes substratos, doses de fertirrigação e inoculação com Azospirillum brasilense. Os bulbilhos foram estabelecidos por dois meses em substrato 50% turfa-50% perlita. Cento e oitenta plantas foram transferidas individualmente para vasos de 3,8 dm3 para avaliação em um experimento com três fatores: 1) tipo de irrigação: 1.1) água ou 1.2) fertirrigação com solução nutritiva de Steiner (NS), NS-50% ou 1.3 ) NS-100%; 2) inoculação com Azospirillum brasilense, 2.1) plantas inoculadas, 2.2) plantas não inoculadas; 3) substrato, misturas de esterco bovino (BM) + areia (S) em diferentes proporções, Mix1: 75% BM + 25% S; Mix2: 25% BM + 75% S; Mix3: 50% BM + 50% S. As características morfológicas foram quantificadas por um ano. As maiores plantas foram aquelas que estavam em substrato com 50% de BM, foram fertirrigadas com NS-100% e inoculadas com Azospirillum brasiliense, enquanto as menores foram aquelas estabelecidas em substrato com menor quantidade de esterco, irrigado apenas com água e sem inoculação, que tinham respectivamente, 71,6 e 54,10 cm de altura, 21 e 15,6 folhas, 76,6 e 62,2 mm de diâmetro do caule, 84,4 e 59,8 cm de diâmetro de roseta.

Is Dairy Effluent an Alternative for Maize Crop Fertigation in Semiarid Regions? An Approach to Agronomic and Environmental Effects.

The reuse of effluents from intensive dairy farms combined with localized irrigation techniques (fertigation) has become a promising alternative to increase crop productivity while reducing the environmental impact of waste accumulation and industrial fertilizers production. Currently, the reuse of dairy effluents through fertigation by subsurface drip irrigation (SDI) systems is of vital importance for arid regions but it has been poorly studied. The present study aimed to assess the greenhouse gas (GHG) emissions, soil properties, and crop yield of a maize crop fertigated with either treated dairy effluent or dissolved granulated urea applied through an SDI system at a normalized N application rate of 200 kg N ha-1. Fertilizer application was divided into six fertigation events. GHG fluxes were measured during fertigation (62-day) using static chambers. Soil properties were measured previous to fertilizer applications and at the harvest coinciding with crop yield estimation. A slight increase in soil organic matter was observed in both treatments for the 20-60 cm soil depth. Both treatments also showed similar maize yields, but the dairy effluent increased net GHG emissions more than urea during the fertigation period. Nevertheless, the net GHG emissions from the dairy effluent were lower than the theoretical CO2eq emission that would have been emitted during urea manufacturing or the longer storage of the effluent if it had not been used, showing the need for life-cycle assessments. Local-specific emission factors for N2O were determined (0.07%), which were substantially lower than the default value (0.5%) of IPCC 2019. Thus, the subsurface drip irrigation systems can lead to low GHG emissions, although further studies are needed.

Impact of Si on C, N, and P stoichiometric homeostasis favors nutrition and stem dry mass accumulation in sugarcane cultivated in tropical soils with different water regimes.

Studies with silicon (Si) in sugarcane indicate a greater response in productivity in plants under stress, and the underlying mechanisms of Si in the crop are poorly reported. In this context, the benefits of Si in the crop's stem production are expected to occur at the C:N:P stoichiometry level in plant tissues, benefiting plants with and without stress. However, the extension of this response may vary in different soils. Thus, this research aimed to evaluate if fertigation with Si modifies the C:N:P stoichiometry and if it can increase sugarcane's nutritional efficiency and vegetative and productive parameters. Therefore, three experiments were installed using pre-sprouted seedlings to cultivate sugarcane in tropical soils belonging to the Quartzarenic Neosol, Eutrophic Red Latosol, and Dystrophic Red Latosol classes. The treatments comprised a 2 × 2 factorial scheme in each soil. The first factor was composed without water restriction (water retention = 70%; AWD) and with water restriction (water retention = 35%; PWD). The second factor presented Si concentrations (0 mM and 1.8 mM) arranged in randomized blocks with five replications. Fertigation with Si increases the Si and P concentration, the C and N efficiency, the C:N ratio, and the dry mass production. However, it decreases the C and N concentration and the C:P, C:Si, and N:P ratios in sugarcane leaves and stems regardless of the water regime adopted in the three tropical soils. Cluster and principal components analysis indicated that the intensity of the beneficial effects of Si fertigation on sugarcane plants varies depending on the cultivation soil and water conditions. We found that Si can be used in sugarcane with and without water stress. It changes the C:N:P homeostasis enough to improve the nutritional efficiency of C, P, N, and, consequently, the dry mass accumulation on the stems, with variation in the different cultivated soils.

Productive and Physico-Chemical Parameters of Tomato Fruits Submitted to Fertigation Doses with Water Treated with Very Low-Frequency Electromagnetic Resonance Fields.

It is known that poorly performed fertigation directly impacts on tomato production and biometric components. In addition, consumers are also affected by interrelated characteristics that interfere with the acceptability of the fruit, such as the physicochemical parameters and nutrients in the fruit. Thus, eco-friendly technologies, such as irrigation with ultra-low frequency electromagnetic treated-water, which attenuates the inadequate management of fertigation, are essential to improve marketable fruit yields. Thus, the objective of the present work was to investigate the impact of treated water with very low-frequency electromagnetic resonance fields in physical, chemical and nutritional parameters at different nutrient solution strengths in tomato fruits. In this study, experiments were carried out in randomized blocks and five doses of fertigation were used (1.5; 2.5; 4.0; 5.5; and 7.0 dS m−1), employing two types of water: electromagnetically treated and untreated. It can be seen that the fertigation affected some parameters, mainly the number of fruits with blossom-end rot, fruit size, and weight. Variance analysis (ANOVA) was performed with the subsequent use of the Tukey test. In all statistical tests, a confidence level of 95% was considered. The soluble solids content increased by 28% as a function of the fertigation doses. The electromagnetically treated water reduced the number of fruits with blossom-end rot by 35% (p < 0.05). Overall, electromagnetic water improved the physicochemical quality parameters and the nutritional status of tomato fruits. Thus, this study demonstrated that green technology could leverage tomato fruit production and quality.

Bokashi, simple superphosphate, and fertigation for the growth and nutrition of hybrid Cattleya (Orchidaceae) / Bokashi, superfosfato simples e fertirrigação no crescimento e nutrição de Cattleya híbrida (Orchidaceae)

Potted flower production is an important floricultural activity. However, there have been few studies on the fertilization management of orchids. Fertigation with urea and potassium chloride is feasible, but little information is available regarding the interaction of these fertilizers with other sources of nutrients. Thus, the present study evaluated the effects of application of bokashi and a simple superphosphate and their interactions with fertigation on the growth and nutrition of hybrid Cattleya. Seedlings of Laeliocattleya Drumbeat × Laeliocattleya Gold Digger hybrid were submitted to two ferti-irrigation levels (absent and present) using urea and potassium chloride as nitrogen and potassium sources, respectively. As complementary fertilization, bokashi and superphosphate were applied singly and in combination. A commercial fertilizer (Peters®) was used as an additional control. Fertigation increased plant height; leaf area; number, length, and diameter of pseudobulbs; dry mass of leaves, pseudobulbs, and roots; and content of chlorophyll, carotenoid, and nitrogen. The application of bokashi resulted in dry mass gain in all plant organs. The combination of fertigation and bokashi was superior to the commercial fertilizer in terms of increased leaf area, chlorophyll A content, carotenoid content, and dry mass.

A produção de flores em vaso é uma importante atividade da floricultura. Todavia, são escassos os estudos sobre o manejo da fertilização em orquídeas. A fertirrigação com ureia e cloreto de potássio é uma prática comum; porém, pouco se sabe sobre suas interações com outras fontes de nutrientes. Nesse sentido, o objetivo do presente estudo foi avaliar o efeito do bokashi e do superfosfato simples e suas interações com a fertirrigação no crescimento e nutrição de um híbrido de Cattleya. Mudas do híbrido entre Laeliocattleya Drumbeat × Laeliocattleya Gold Digger foram submetidas à dois regimes de fertirrigação (ausência e presente) utilizando ureia e cloreto de potássio como fonte de nitrogênio (N) e potássio (K), respectivamente. Além disso, como fertilização complementar foi utilizado o bokashie superfosfato, aplicados isolados e em combinação. O fertilizante comercial Peters® foi utilizado como testemunha adicional. A fertirrigação propiciou incrementos na altura, área foliar, número, comprimento e diâmetro dos pseudobulbos, bem como na massa seca de folhas, pseudobulbos e raízes, além de aumento nos teores de clorofila, carotenoides e teor de N. O uso do bokashi resultou em ganhos na massa seca em todos os órgãos da planta. A utilização combinada entre a fertirrigação e bokashi foi superior ao fertilizante comercial para as características área foliar, teor de clorofila A, carotenoides, além das características de massa seca.

Bokashi, simple superphosphate, and fertigation for the growth and nutrition of hybrid Cattleya (Orchidaceae) / Bokashi, superfosfato simples e fertirrigação no crescimento e nutrição de Cattleya híbrida (Orchidaceae)

Potted flower production is an important floricultural activity. However, there have been few studies on the fertilization management of orchids. Fertigation with urea and potassium chloride is feasible, but little information is available regarding the interaction of these fertilizers with other sources of nutrients. Thus, the present study evaluated the effects of application of bokashi and a simple superphosphate and their interactions with fertigation on the growth and nutrition of hybrid Cattleya. Seedlings of Laeliocattleya Drumbeat × Laeliocattleya Gold Digger hybrid were submitted to two ferti-irrigation levels (absent and present) using urea and potassium chloride as nitrogen and potassium sources, respectively. As complementary fertilization, bokashi and superphosphate were applied singly and in combination. A commercial fertilizer (Peters®) was used as an additional control. Fertigation increased plant height; leaf area; number, length, and diameter of pseudobulbs; dry mass of leaves, pseudobulbs, and roots; and content of chlorophyll, carotenoid, and nitrogen. The application of bokashi resulted in dry mass gain in all plant organs. The combination of fertigation and bokashi was superior to the commercial fertilizer in terms of increased leaf area, chlorophyll A content, carotenoid content, and dry mass.(AU)

A produção de flores em vaso é uma importante atividade da floricultura. Todavia, são escassos os estudos sobre o manejo da fertilização em orquídeas. A fertirrigação com ureia e cloreto de potássio é uma prática comum; porém, pouco se sabe sobre suas interações com outras fontes de nutrientes. Nesse sentido, o objetivo do presente estudo foi avaliar o efeito do bokashi e do superfosfato simples e suas interações com a fertirrigação no crescimento e nutrição de um híbrido de Cattleya. Mudas do híbrido entre Laeliocattleya Drumbeat × Laeliocattleya Gold Digger foram submetidas à dois regimes de fertirrigação (ausência e presente) utilizando ureia e cloreto de potássio como fonte de nitrogênio (N) e potássio (K), respectivamente. Além disso, como fertilização complementar foi utilizado o bokashie superfosfato, aplicados isolados e em combinação. O fertilizante comercial Peters® foi utilizado como testemunha adicional. A fertirrigação propiciou incrementos na altura, área foliar, número, comprimento e diâmetro dos pseudobulbos, bem como na massa seca de folhas, pseudobulbos e raízes, além de aumento nos teores de clorofila, carotenoides e teor de N. O uso do bokashi resultou em ganhos na massa seca em todos os órgãos da planta. A utilização combinada entre a fertirrigação e bokashi foi superior ao fertilizante comercial para as características área foliar, teor de clorofila A, carotenoides, além das características de massa seca.(AU)

Identification of organic contaminants in vinasse and in soil and groundwater from fertigated sugarcane crop areas using target and suspect screening strategies.

This work evaluated for the first time the sustainability of vinasse reuse as a fertilizer in sugarcane crops by assessing the occurrence of organic contaminants and their potential for dissemination to soils and groundwater in fertigated areas. A comprehensive screening of organic contaminants was performed in vinasse, soil and groundwater using target analysis, to investigate the occurrence of multiple-class antibiotics, in combination with suspect screening using NORMAN Digital Sample Freezing Platform. Even though antibiotics are used in the ethanol production process and were expected to be ubiquitous contaminants, they were not detected in any of the samples. Nevertheless, the HRMS-based wide-scope suspect screening (including >7800 substances such as pharmaceuticals, agrochemicals, preservatives and industrial chemicals) allowed the tentative identification of 56 compounds, mostly pesticides, food additives, industrial and naturally occurring substances. Results showed no overlap between the compounds detected in vinasse and environmental samples, suggesting that the pollutants found in soil and groundwater might come from alternative sources other than vinasse reuse.

Efficiency of nitrogen and potassium application on phytotechnical parameters and yield of melon / Eficiência da aplicação de nitrogênio e potássio sobre caracteres fitotécnicos e rendimento do meloeiro

Phytotechnical parameters, yield and fertilizer use efficiency are relevant to the rational management of fertigation, especially in cultivation of high technological level. Thus, the objective was to evaluate the influence and efficiency of nitrogen (N) and potassium (K) application on the phytotechnical parameters, yield and nutritional efficiency of yellow melon in a fertigation system. The experiment was conducted in the city of Bom Jesus-PI, Brazil, from January to April 2016, in a strip-block design with four replicates, and the treatments consisted of five N levels (0, 45, 90, 135 and 180 kg ha-1 in the form of urea) and five K levels (0, 60, 120, 180 and 240 kg ha-1 in the form of potassium chloride), applied through fertigation. Collar diameter, main branch length, leaf chlorophyll content, number of leaves, leaf area index, biomass accumulation, fruit yield, and N and K use efficiencies were evaluated. Applications of 180 kg ha-1 of N and 240 kg ha-1 of K, respectively, led to the highest growth of the melon, while maximum production was obtained with the use of 112.50 and 165 kg ha-1 of N and K, respectively. The efficiency of N and K use decreased with increasing levels.

As características fitotécnicas, de rendimento e de eficiência de uso dos fertilizantes são relevantes para o manejo racional da fertirrigação, especialmente em cultivo de elevado nível tecnológico. Níveis crescentes de N e K promoverão maior crescimento e produtividade do meloeiro. Neste sentido, objetivou-se avaliar a influência e a eficiência da aplicação de nitrogênio e potássio sobre as características fitotécnicas, de rendimento e de eficiência do meloeiro amarelo em sistema de fertirrigação. O experimento foi conduzido na cidade de Bom Jesus ­ PI, Brasil durante o período de janeiro a abril de 2016. O delineamento experimental adotado foi de blocos em faixas com quatro repetições, e os tratamentos constituídos por cinco níveis de nitrogênio (0, 45, 90, 135 e 180 kg ha-1 na forma de ureia) e cinco níveis de potássio (0, 60, 120, 180 e 240 kg ha-1na forma de cloreto de potássio) aplicados via fertirrigação. Avaliou-se os caracteres fitotécnicos, rendimento de frutos e as eficiências de uso do nitrogênio e do potássio. As aplicações de 180 kg ha-1 de N e 240 kg ha-1 de K promoveram maior crescimento do meloeiro, enquanto que a máxima produção foi obtida com o uso de 112,50 e 165 kg ha-1 de nitrogênio e potássio, respectivamente. As eficiências de uso do nitrogênio e do potássio diminuíram com o aumento dos níveis aplicadas.

Green Manure Species for Phytoremediation of Soil With Tebuthiuron and Vinasse.

Tebuthiuron is often used to control weed growth in sugarcane cultures. This herbicide is highly toxic and can persist in soil for up to 2 years according to its degradation half-life. Hence, its residual effect is highly hazardous for the environment and local habitants via leaching, surface runoff. Screening out of species of green manure as potential phytoremediators for tebuthiuron in soil, with and with no vinasse, accordingly is the scientific point of this study. Green manure species selected for the trial in greenhouse were jack bean [Canavalia ensiformis (L.) DC.], pigeon pea [Cajanus cajan (L. Millsp.)], velvet bean [Mucuna pruriens (L.) DC.)], and millet [Pennisetum glaucum (L.) R.Br.], and Crotalaria juncea L. as bioindicator of this herbicide. The determination/quantification of height, stem diameter, and number of leaves in all plants were monitored, as well as other morphological traits for drafting any inference on biomass production. Moreover, ecotoxicity bioassays were performed from soil samples at the beginning and at the end of the experiment. Results showed preliminary evidence of effective phytoremediation capacity by M. pruriens and P. glaucum in soils with tebuthiuron, as the growth of C. juncea was sustained. Both Gompertz approach and principal component analysis predicted that these green manure species could grow healthier and for longer periods in soils containing tebuthiuron and vinasse and, thus, reduce physiological anomalies due to ecotoxicity. The implications of this study may aid in the implementation of cost-effective strategies targeting decontamination of tebuthiuron in sugarcane crops with vinasse application in fertigation.

Seasonal variation of the organic and inorganic composition of sugarcane vinasse: main implications for its environmental uses.

Sugarcane vinasse is the main waste stream of the Brazilian agroindustry. The typical composition of sugarcane vinasse gives it a high polluting potential that implies the necessity to define sustainable strategies for managing this waste. Knowledge of the inorganic and organic composition of vinasse and its seasonal variation is extremely important to conduct scientific research to define alternative managements for vinasse disposal other than fertigation. This study evaluated the variability of vinasse composition throughout the same harvesting season and among three harvesting seasons of one Brazilian annexed biorefinery (2015-2017). The contents of chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total solids (TS), suspended solids (SS), salinity (K+, Na+, Ca2+, Mg2+, Cl-, F-), nutrients (N, P, S), trace metals (Al3+, As2+, Ba2+, Cd2+, Cr3+, Co2+, Cu2+, Fe2+, Pb2+, Mn2+, Hg2+, Mo2+, Ni2+, Se2+, Zn2+), and specific soluble organic compounds (sugars, alcohols, and organic acids), as well as pH and conductivity, were monitored in 13 samples. The results indicated that sugarcane vinasse is a suitable feedstock for biological treatments, such as anaerobic digestion processes for energy recovery, as well as substrate for biomass (e.g., microalgae, energy crops, lignocellulosic biomass) growth. The application of a previous treatment makes vinasse a more environmentally friendly natural fertilizer for land fertigation.

Fertigation: Nutrition, Stimulation and Bioprotection of the Root in High Performance.

Temperature changes, drought, frost, and the presence of pest and diseases place enormous stress on crops, which implies that the potential performance of these crops may be affected. One of the main goals for agronomists, horticulturists, growers, physiologists, soil scientists, geneticists, plant breeders, phytopathologists, and microbiologists is to increase the food production on the same cultivable area and to ensure that they are safe and of high quality. Understanding the biophysical changes in soil will help to manage the crop's ability to cope with biotic and abiotic stress. Optimization is needed in the nutrition of crops, which involves the use of biostimulants to counter oxidative stress and the management of strain bioformulations (bacteria and fungi) that protect and stimulate roots for the acquisition of nutrients. The implementation of these strategies in fertigation programs improves crop yields. This article addresses the importance of the stimulation and the bioprotection of the root as a fundamental pillar in ensuring the high performance of a crop.

Phytotoxicity of effluents from swine slaughterhouses using lettuce and cucumber seeds as bioindicators.

This study evaluated the phytotoxic effects of raw and treated effluents from a swine slaughterhouse on cucumber and lettuce seeds and determined correlations among physicochemical characteristics of such effluents and the germination of seeds used as bioindicators. Physicochemical parameters were characterized for both effluents and their phytotoxicity was determined through the germination index (GI), the root length (RL) and the number of germinated seeds (SG) for both plant species. The effluents treatment system was efficient to reduce the concentration of some physicochemical parameters to levels within those recommended by the Brazilian legislation, except for P, ammoniacal N and TKN concentration. Although phytotoxicity of the treated effluent was less in comparison to the raw effluent, the GI for cucumber and lettuce seeds submitted to each of the tested effluents was lower than 80%. Thus, both effluents were phytotoxic for the tested bioindicators (p<0.05). For lettuce seeds, the GI presented negative correlations (p<0.05) with the total Kjeldahl N (-0.93) and the surfactants concentration (-0.83) in the raw effluent. The Zn concentration in the treated effluent showed a negative correlation (p<0.05) with the GI of both lettuce (-0.63) and cucumber seeds (-0.64). Therefore, effluents from swine slaughterhouses may impair the germination of the evaluated plant species if used for agricultural purposes.

Produção de capim elefante utilizando percolado de aterro sanitário / Production of elephant grass using leachate landfill

O uso do percolado de aterro sanitário (PAS) na produção de biomassa para fins energéticos é uma alternativa que minimiza a degradação ambiental. O presente trabalho objetivou analisar o efeito de distintas doses de PAS na produção de capim elefante (Pennisetum purpureum Schum.). Para isso, montou-se o experimento no delineamento em blocos casualizados, com cinco tratamentos (T1 - somente água de abastecimento - AA; T2 - 1mm dia-1 de PAS mais AA; T3 - 2mm dia-1 de PAS mais AA; T4 - 3mm dia-1 de PAS mais AA; e T5 - 4mm dia-1 de PAS mais AA) e cinco repetições, totalizando 25 parcelas experimentais. O capim elefante foi cultivado em ARGISSOLO VERMELHO - AMARELO Eutrófico, durante 132 dias em Mossoró/RN. Ao final do ciclo do capim elefante foram determinadas as características vegetativas altura de planta (AP), massa úmida da planta (MUP) e da folha (MUF) e massa seca das folhas (MSF). Comprovou-se para MUP, MUF e MSF que não houve diferença estatística entre os tratamentos, entretanto, para AP, o tratamento T2 apresentou maior valor (2,86m), diferindo estatisticamente dos tratamentos T4 e T5. Em geral, o tratamento T2 apresentou melhor desempenho com relação às características vegetativas do capim elefante.

The use of landfill leachate (PAS) in the production of biomass for energy is an alternative that minimizes environmental degradation. This study aimed to analyze the effect of different doses of PAS in elephant grass production (Pennisetum purpureum Schum.). For this, the experiment was set up in a randomized block design with five treatments (T1 - only water supply - AA, T2 - 1 mm day-1 of PAS more AA, T3 - 2 mm day-1 of PAS more AA, T4 - 3 mm day-1 of PAS more AA and T5 - 4 mm day -1 of PAS more AA) and five repetitions, totaling 25 experimental plots. The elephant grass was cultivated in ultisol during 132 days in Mossoró/RN. At the end of elephant grass cycle were determined vegetative characteristics plant height (PH), plant fresh weight (MUP), leaf fresh weight (MUF) and leaf dry weight (MSF). It was shown to MUP, MUF and MSF that there was no statistical difference between the treatments, however, to AP, T2 treatment the highest values (2.86 m), differing of the treatments T4 and T5. In general, treatment T2 showed a better performance with respect to elephant grass vegetative characteristics.