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1.
Braz. j. biol ; 83: e246436, 2023. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1339391

ABSTRACT

Abstract Application of different fertilizers to check the efficiency of expression of Bt (Bacillus thuringiensis) gene in one of the leading commercialized crops (cotton) against Lepidopteran species is of great concern. The expression of Cry protein level can be controlled by the improvement of nutrients levels. Therefore, the myth of response of Cry toxin to different combinations of NP fertilizers was explored in three Bt cotton cultivars. Combinations include three levels of nitrogen and three levels of phosphorus fertilizers. Immunostrips and Cry gene(s) specific primer based PCR (Polymerase Chain Reaction) analysis were used for the presence of Bt gene that unveiled the presence of Cry1Ac gene only. Further, the ELISA (enzyme-linked immunosorbent assay) kit was used to quantify the expression of Cry1Ac protein. Under various NP fertilizers rates, the level of toxin protein exhibited highly significant differences. The highest toxin level mean was found to be 2.3740 and 2.1732 µg/g under the treatment of N150P75 kg ha-1 combination while the lowest toxin level mean was found to be 0.9158 and 0.7641 µg/g at the N50P25 kg ha-1 level at 80 and 120 DAS (Days After Sowing), respectively. It was concluded from the research that the usage of NP fertilizers has a positive relation with the expression of Cry1Ac toxin in Bt cotton. We recommend using the N150P50 kg ha-1 level as the most economical and practicable fertilizer instead of the standard dose N100P50 kg ha-1 to get the desired level of Cry1Ac level for long lasting plant resistance (<1.5). The revised dose of fertilizer may help farmers to avoid the cross-resistance development in contradiction of insect pests.


Resumo A aplicação de diferentes fertilizantes para verificar a eficiência da expressão do gene Bt (Bacillus thuringiensis) em uma das principais culturas comercializadas (algodão) contra espécies de lepidópteros é uma grande preocupação. A expressão do nível de proteína Cry pode ser controlada pela melhoria dos níveis de nutrientes. Portanto, o mito da resposta da toxina Cry a diferentes combinações de fertilizantes NP foi explorado em três cultivares de algodão Bt. As combinações incluem três níveis de nitrogênio e três níveis de fertilizantes de fósforo. A análise de PCR (reação em cadeia da polimerase) específica para o gene (s) Immunostrips e Cry (s) foi usada para a presença do gene Bt que revelou a presença do gene Cry1Ac apenas. Além disso, o kit ELISA (ensaio de imunoabsorção enzimática) foi usado para quantificar a expressão da proteína Cry1Ac. Sob várias taxas de fertilizantes NP, o nível de proteína de toxina exibiu diferenças altamente significativas. A média do nível mais alto de toxina foi de 2,3740 e 2,1732 µg / g sob o tratamento da combinação N150P75 kg ha-1, enquanto a média do nível mais baixo de toxina foi de 0,9158 e 0,7641 µg / g no nível de N50P25 kg ha-1 em 80 e 120 DAS (dias após a semeadura), respectivamente. Concluiu-se com a pesquisa que o uso de fertilizantes NP tem relação positiva com a expressão da toxina Cry1Ac no algodão Bt. Recomendamos o uso do nível de N150P50 kg ha-1 como o fertilizante mais econômico e praticável em vez da dose padrão N100P50 kg ha-1 para obter o nível desejado de nível de Cry1Ac para resistência de planta de longa duração (<1,5). A dose revisada de fertilizante pode ajudar os agricultores a evitar o desenvolvimento de resistência cruzada em contradição com as pragas de insetos.


Subject(s)
Animals , Hemolysin Proteins/genetics , Moths , Phosphorus , Bacterial Proteins/genetics , Insecticide Resistance , Plants, Genetically Modified/genetics , Endotoxins/genetics , Fertilizers , Bacillus thuringiensis Toxins , Larva , Nitrogen
2.
Braz. j. biol ; 82: e235573, 2022. tab, graf
Article in English | LILACS | ID: biblio-1249228

ABSTRACT

Abstract In the tropical region, savannas and seasonal forests, both highly diverse biomes, occur side by side, under the same climate. If so, that mosaic cannot be explained solely by climatic variables, but also by fire, water availability and soil status. Nutrient availability in the soil, especially nitrogen and phosphorus, has been postulated to explain the abrupt transitions between savannas and seasonal forests in tropical regions. Plants from these two biomes may present different nutritional strategies to cope with nitrogen and phosphorus limitation. We used two congeneric pairs of trees — each pair with a species from the savanna and another from the neighboring seasonal forest — to test whether savanna and forest species presented different nutritional strategies during their early development. We cultivated 56 individuals from each of these species in a hydroponics system with four treatments: (1) complete Hoagland solution, (2) Hoagland solution without nitrogen, (3) Hoagland solution without phosphorus, and (4) Hoagland solution without nitrogen and phosphorus. After 45 days, we harvested the plants and measured total biomass, root to shoot ratio, height, leaf area, and specific leaf area. Overall, savanna species were lighter, shorter, with smaller leaves, higher specific leaf areas, and higher root to shoot ratios when compared to the forest species. Nitrogen increased the performance of species from both biomes. Phosphorus improved the performance of the forest species and caused toxicity symptoms in the savanna species. Hence, savanna and forest species presented different demands and were partially distinct already as seedlings concerning their nutritional strategies.


Resumo Em regiões tropicais, savanas e florestas estacionais, biomas altamente diversos, ocorrem lado a lado, sob o mesmo clima. Sendo assim, esse mosaico não pode ser explicado somente por variáveis ​​climáticas, devendo ser considerada a frequência e intensidade de incêndios, disponibilidade de água e status do solo. A disponibilidade de nutrientes no solo, especialmente nitrogênio e fósforo, tem sido postulada para explicar as transições abruptas entre savanas e florestas estacionais nos trópicos. Espécies vegetais desses dois biomas podem apresentar estratégias nutricionais diferentes para lidar com a limitação tanto de nitrogênio como de fósforo. Utilizamos dois pares de árvores congenéricas — cada par com uma espécie típica de savana e outra de floresta estacional vizinha — para testar se as espécies da savana e da floresta apresentaram estratégias nutricionais diferentes durante seu desenvolvimento inicial. Cultivamos 56 indivíduos de cada uma dessas espécies em um sistema hidropônico com quatro tratamentos: (1) solução Hoagland completa, (2) solução Hoagland sem nitrogênio, (3) solução Hoagland sem fósforo e (4) solução Hoagland sem nitrogênio e fósforo. Após 45 dias, colhemos as plantas e medimos a biomassa total, a relação raiz / parte aérea, altura, área foliar e área foliar específica. No geral, as espécies savânicas foram mais leves, menores em altura, área foliar e área foliar específica e apresentaram maiores razões entre biomassa radicular por biomassa aérea quando comparadas às espécies florestais. A oferta de nitrogênio aumentou o desempenho das espécies de ambos biomas. O fósforo melhorou o desempenho das espécies florestais e causou sintomas de toxicidade nas espécies savânicas. Concluímos que, já como mudas, espécies congenéricas de savana e floresta apresentaram demandas distintas e foram parcialmente diferentes em relação a suas estratégias nutricionais.


Subject(s)
Humans , Grassland , Nitrogen , Phosphorus , Soil , Trees , Tropical Climate , Forests , Plant Leaves
3.
Braz. j. biol ; 82: e233567, 2022. tab, graf
Article in English | LILACS | ID: biblio-1249220

ABSTRACT

Abstract This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3- and ammonium - NH4+) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4+ form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+/K+, Na+/Ca++ and Na+/Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-1 reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4+ under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3- form the most suitable for the cultivation of the species.


Resumo Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos dos íons nitrato e amônio sobre o acúmulo de nutrientes e produção da abobrinha italiana (cv. Caserta) cultivada em sistema hidropônico sob estrese salino. O experimento foi conduzido em casa de vegetação utilizando o delineamento experimental em blocos casualizados, arranjados em esquema fatorial 2 x 5, com 4 repetições. Os tratamentos foram constituídos de duas formas de nitrogênio (nitrato - NO3- e amônio - NH4+) e cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,5; 2,0; 3,5; 5,0 e 6,5 dS m-1). As análises dos resultados indicaram que suprimento de N exclusivamente em forma de NH4+ promove maiores danos na membrana foliar e redução no acúmulo de macronutrientes e maiores relações Na+/K+, Na+/Ca++ e Na+/Mg++ na parte aérea das plantas de abobrinha. A irrigação com água a cima de 2,0 dS m-1 reduz o acúmulo de nutrientes na parte aérea das plantas e a produção de abobrinha. A toxicidade do NH4+ sob abobrinha italiana sobrepõe-se à toxicidade da salinidade, pois a fertilização exclusiva com esta forma de nitrogênio inibe sua produção, sendo a forma NO3- a mais adequada para o cultivo da espécie.


Subject(s)
Ammonium Compounds , Nitrogen , Plant Roots/chemistry , Salt Stress , Homeostasis , Italy , Nitrates
4.
Braz. j. biol ; 82: e227703, 2022. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1285590

ABSTRACT

Abstract A research was conducted to evaluate the impact of various nitrogen and phosphorus levels along with beneficial microbes to enhance canola productivity. The research was carried out at Agronomy Research Farm, The University of Agriculture Peshawar in winter 2016-2017. The experiment was conducted in randomized complete block factorial design. The study was comprised of three factors including nitrogen (60, 120 and 180 kg ha-1), phosphorous (70, 100 and 130 kg ha-1) and beneficial microbes (with and without BM). A control treatment with no N, P and BM was also kept for comparison. Application of beneficial microbes significantly increased pods plant, seed pod, seed filling duration, 1000 seed weight, biological yield and seed yield as compared to control plots. Nitrogen applied at the rate of 180 kg ha-1 increased pods plant-1, seed pod, seed filling duration, seed weight, biological yield and seed yield. Maximum pods plant-1, seed pod, early seed filling, heavier seed weight, biological yield, seed yield, and harvest index were observed in plots treated with 130 kg.ha-1 phosphorous. As comparison, the combine treated plots have more pods plant-1, seeds pod-1, seed filling duration, heaviest seeds, biological yield, seed yield and harvest index as compared to control plots. It is concluded that application of beneficial microbes with N and P at the rate of 180 kg ha-1 and 130 kg ha-1, respectively, increased yield and its attributes for canola.


Resumo Uma pesquisa foi realizada para avaliar o impacto de vários níveis de nitrogênio e fósforo, juntamente com micróbios benéficos, para aumentar a produtividade da canola. A pesquisa foi realizada no inverno de 2016-17 no Agronomy Research Farm, Universidade de Agricultura do Peshawar. O experimento foi conduzido por planejamento fatorial aleatorizado em blocos. O estudo focou-se em três fatores, incluindo o teor de nitrogênio, N, (60, 120 e 180 kg.ha-1), o teor de fósforo, P, (70, 100 e 130 kg ha-1) e a presença de micróbios benéficos (com BM e sem BM). Para fins de comparação, um tratamento controle sem N, P e BM também foi incluído no estudo. A aplicação de micróbios benéficos aumentou significativamente as vagens das plantas e de sementes, a duração do enchimento das sementes, o peso de 1000 sementes, o rendimento biológico e o rendimento de sementes em comparação com os resultados do controle. O nitrogênio aplicado na taxa de 180 kg ha-1 aumentou as vagens por planta, vagem, duração do enchimento, peso da semente, rendimento biológico e rendimento de sementes. Vagens máximas por planta, vagem, enchimento precoce de sementes, peso maior de semente, rendimento biológico, rendimento de sementes e índice de colheita foram observados em parcelas tratadas com 130 kg.ha-1 de fósforo. Em comparação aos blocos cultivados de controle, os blocos cultivados tratados combinados têm mais vagens por planta e sementes por vagem, maior duração do enchimento das sementes, maior número de sementes mais pesadas e maior rendimento biológico, rendimento de sementes e índice de colheita. Conclui-se que a aplicação de micróbios benéficos junto com N e P nas doses de 180 kg ha-1 e 130 kg ha-1, respectivamente, aumentou a produtividade e atributos de produtividade para a canola.


Subject(s)
Phosphorus , Nitrogen , Seasons , Seeds , Agriculture
5.
Braz. j. biol ; 82: e240133, 2022. tab
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1278516

ABSTRACT

Abstract A field study was carried out to determine the influence of foliage applied plant growth promoter and retardant in improving soil applied sulphur fertilizer use efficiency in cotton during two consecutive summers 2014 and 2015. Experimental trial comprised of three different sources of sulphur (ammonium sulphate, potassium sulphate and elemental sulphur) and foliar spray of plant growth promoter and growth retardant including tap water was taken as control. Among treatments soil applied ammonium sulphate with foliage applied amino acid produced maximum plant height, sympodial branches, pods per plant, seed cotton yield, fiber yield, biological yield, protein contents, oil contents and leaf nitrogen uptake as compared to the other treatments. Whereas, soil applied potassium sulphate with foliar spray of mepiquat chloride on cotton significantly improved the boll weight and leaf potassium uptake. We conclude that soil applied ammonium sulphate and foliage spray of amino acid was more effective in improving the productivity and quality attributes of cotton.


Resumo Foi realizado um estudo de campo para determinar a influência do promotor de crescimento das plantas e retardador da folhagem em algodão, para melhora da eficiência do uso de fertilizantes à base de enxofre aplicados no solo durante dois verões consecutivos (2014 e 2015). O ensaio experimental foi composto de três fontes diferentes de enxofre (sulfato de amônio, sulfato de potássio e enxofre elementar) e pulverização foliar do promotor de crescimento de plantas e retardador de crescimento, incluindo água da torneira que foi tomada como controle. Entre os tratamentos, o sulfato de amônio aplicado no solo com aminoácido aplicado na folhagem produziu o máximo na altura da planta, ramos simodiais, capulhos por planta, rendimento de algodão em caroço, rendimento de fibra, rendimento biológico, conteúdo de proteínas, conteúdo de óleo e absorção de nitrogênio nas folhas quando comparado a outros tratamentos. Enquanto o solo fertilizado com sulfato de potássio e aplicação foliar de cloreto de mepiquat no algodão melhorou, significativamente, o peso do capulho e a absorção de potássio nas folhas. Sulfato de amônio aplicado no solo e a aplicação foliar de aminoácidos foram mais eficazes na melhora dos atributos de produtividade e qualidade do algodão.


Subject(s)
Amino Acids , Nitrogen , Soil , Fertilizers , Ammonium Sulfate
6.
Braz. j. biol ; 81(3): 544-550, July-Sept. 2021. tab, graf
Article in English | LILACS | ID: biblio-1153416

ABSTRACT

Abstract A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.


Resumo Uma análise de viabilidade do tratamento terciário para Resíduos Agrícola Líquidos Orgânicos é apresentada usando algas filamentosas pertencentes ao gênero Cladophora sp. como alternativa ao tratamento químico terciário. Os tratamentos terciários que utilizam sistemas biológicos têm baixo custo de investimento e a dependência de variáveis ​​ambientais é mínima. Neste trabalho, é demonstrado que essas algas filamentosas reduzem a carga nutricional de nitrato (circa 75%) e fosfato (circa 86%) dos efluentes de resíduos orgânicos provenientes de fazendas de leite em nove dias de cultura e tem a vantagem de que as algas podem ser facilmente coletadas posteriormente. Atualmente, as águas residuais orgânicas são descartadas nos campos e córregos locais. Posteriormente, as algas podem ser consideradas como matéria prima, uma vez que possuem várias utilidades como composto, celulose e biogás. Uma desvantagem desse sistema é que água limpa deve ser usada para obter transparência de água suficiente para permitir o crescimento de algas. Mesmo assim, o sistema de redução de nutrientes dos efluentes orgânicos propostos e amigável ao ecossistema, comparado aos tratamentos terciários que utilizam produtos químicos para precipitar e coletar nutrientes como nitratos e fosfatos.


Subject(s)
Waste Disposal, Fluid , Ecosystem , Nutrients , Waste Water/analysis , Nitrates , Nitrogen
7.
Chinese Journal of Biotechnology ; (12): 3685-3695, 2021.
Article in Chinese | WPRIM | ID: wpr-921457

ABSTRACT

Biological denitrification is the most widely used technology for nitrate removal in wastewater treatment. Conventional denitrification requires long hydraulic retention time, and the nitrate removal efficiency in winter is low due to the low temperature. Therefore, it is expected to develop new approaches to enhance the denitrification process. In this paper, the effect of adding different concentrations of Fe₃O₄ nanoparticles on the denitrification catalyzed by Pseudomonas stutzeri was investigated. The maximum specific degradation rate of nitrate nitrogen improved from 18.0 h⁻¹ to 23.7 h⁻¹ when the concentration of Fe₃O₄ increased from 0 mg/L to 4 000 mg/L. Total proteins and intracellular iron content also increased along with increasing the concentration of Fe₃O₄. RT-qPCR and label-free proteomics analyses showed that the relative expression level of denitrifying genes napA, narJ, nirB, norR, nosZ of P. stutzeri increased by 55.7%, 24.9%, 24.5%, 36.5%, 120% upon addition of Fe₃O₄, and that of denitrifying reductase Nap, Nar, Nir, Nor, Nos increased by 85.0%, 147%, 16.5%, 47.1%, 95.9%, respectively. No significant difference was observed on the relative expression level of denitrifying genes and denitrifying reductases between the bacteria suspended and the bacteria adhered to Fe₃O₄. Interestingly, the relative expression level of electron transfer proteins of bacteria adhered to Fe₃O₄ was higher than that of the bacteria suspended. The results indicated that Fe₃O₄ promoted cell growth and metabolism through direct contact with bacteria, thereby improving the denitrification. These findings may provide theoretical support for the development of enhanced denitrification.


Subject(s)
Aerobiosis , Denitrification , Nitrates , Nitrogen , Pseudomonas stutzeri/genetics
8.
Chinese Journal of Biotechnology ; (12): 3505-3519, 2021.
Article in Chinese | WPRIM | ID: wpr-921444

ABSTRACT

Denitrification is an indispensable part of most sewage treatment systems. The biological denitrification process has attracted much attention in the past decades due to the advantages such as cost-effectiveness, process simplicity, and absence of secondary pollution. This review summarized the advances on biological denitrification processes in recent years according to the different physiological characteristics and denitrification mechanisms of denitrification microorganisms. The pros and cons of different biological denitrification processes developed based on nitrifying bacteria, denitrifying bacteria, and anaerobic ammonia-oxidizing bacteria were compared with the aim to identify the best strategy for denitrification in a complex wastewater environment. The rapid development of synthetic biology provides possibilities to develop highly-efficient denitrifying strains based on mechanistic understandings. Combined with the applications of automatic simulation to obtain the optimal denitrification conditions, cost-effective and highly-efficient denitrification processed can be envisioned in the foreseeable future.


Subject(s)
Aerobiosis , Denitrification , Nitrification , Nitrogen , Waste Water
9.
Chinese Journal of Biotechnology ; (12): 3276-3292, 2021.
Article in Chinese | WPRIM | ID: wpr-921424

ABSTRACT

Due to the special geographical location and the complex ecosystem types, plateau wetlands play important ecological roles in water supply, greenhouse gas regulation and biodiversity preservation. Napahai plateau wetland is a special wetland type with low latitude and high altitude, and its microbial diversity was rarely studied. The diversity of microbial communities in the Napahai plateau wetland was analyzed using metagenomics method. Among the microbes detected, 184 phyla, 3 262 genera and 24 260 species belong to the bacterial domain, 13 phyla and 32 genera belong to the archaeal domain, and 13 phyla and 47 genera belong to the fungal domain. Significant differences in species diversity between soil and water were observed. Acidobacteria, Proteobacteria and Actinobacteria were dominant phyla in soil, while Proteobacteria and Bacteroides were dominant phyla in water. Since the carbon and nitrogen metabolism genes were abundant, the pathways of carbon fixation and nitrogen metabolism were analyzed. Calvin cycle, reductive tricarboxylic acid cycle and 3-hydroxypropionic acid cycle were the main carbon fixation pathways, while Proteobacteria, Chloroflexi, and Crenarchaeota were the main carbon-fixing bacteria group. As for the nitrogen cycle, nitrogen fixation and dissimilatory nitrate reduction were dominant in water, while nitrification and denitrification were dominant in soil. Proteobacteria, Nitrospirae, Verrucomicrobia, Actinobacteria, Thaumarchaeota and Euryarchaeota contributed to the nitrogen cycle. The study on microbial diversity of Napahai plateau wetlands provides new knowledge for the comprehensive management and protection of wetland environment in China.


Subject(s)
Carbon , Ecosystem , Metagenomics , Nitrogen , Soil Microbiology , Wetlands
10.
Article in Chinese | WPRIM | ID: wpr-879111

ABSTRACT

The study is aimed through field experiments to study the effect of combined application of organic and chemical fertilizers on the growth and quality of Salvia miltiorrhiza, provide ideas for reducing fertilization while increasing the efficiency as well as improving the quality of produces. The experiment included 6 treatments viz., no fertilization(CK), full application of chemical fertilizer(F), 25% orga-nic fertilizer with 75% chemical fertilizer(M25), 50% organic fertilizer with 50% chemical fertilizer(M50), 75% organic fertilizer with 25% chemical fertilizer(M75), and fully apply organic fertilizer(M100). The results showed that:(1)from the perspective of yield and economic benefits, M75 was the best and M100 second;(2)for effective components, the combined application of organic and chemical fertilizers increased the content of main water-soluble components and the total content of effective components, among which M25 and M50 were better.


Subject(s)
Agriculture , Fertilizers/analysis , Nitrogen , Salvia miltiorrhiza , Soil
11.
Article in Chinese | WPRIM | ID: wpr-879108

ABSTRACT

Nitrogen fertilizers play an important role in the regulation of plant stress resistance. Impacts of nitrogen fertilizers on abiotic stress resistance and biotic stress resistance of Chinese materia medica(CMM) were summarized in this study. Adequate nitrogen application improves the abiotic stress resistance and weed resistance of CMM, however adverse effect appears when excess nitrogen is used. Generally, pest resistance decreases along with nitrogen deposition, while effects of nitrogen application on disease resistance vary with different diseases. Mechanisms underlying the impact of nitrogen fertilizers on plant stress resistance were also elucidated in this study from three aspects including physical defense mechanisms, biochemistry mechanisms and molecular defense mechanisms. Nitrogen availability modulates physical barrier of CMM like plant growth, formation of lignin and wax cuticle, and density of stomata. Growth of CMM promoted by nitrogen fertilizer may cause some decrease in pest resistance of CMM due to an increase in hiding places for pest along with plant growth. High ambient humidity caused by excessive plant growth facilitates the growth and development of CMM pathogen. Nitrogen application can also interfere with the accumulation of lignin in CMM which makes CMM more vulnerable to pest and pathogen attack. Stomatal closing delays due to nitrogen application is also a causal factor of increasing pathogen infection after nitrogen deposition. Biochemical defenses of plants are mainly achieved through nutrient elements, secondary metabolites, defense-related enzymes and proteins. Nutritional level of CMM and various antioxidant enzymes and resistance-related protein activities are elevated along with nitrogen deposition. These antioxidant enzymes can reduce the damage of reactive oxygen species content produced by plant in response to adversity and therefore enhance stress resistance of CMM. Researches showed that nitrogen application could also cause an increase in nitrogen-containing secondary metabolites content and a decrease in non-nitrogen-containing secondary metabolites content respectively. Nitrogen-mediated molecular defense mechanisms includes multiple plant hormones and nitric oxide signals. Plant hormones related to plant defense like salicylic acid, jasmonic acid and abscisic acid can be modulated by nitrogen application. Negative effect of nitrogen deposition was found on salicylic acid accumulation and the expression of related plant disease resistance genes. However, jasmonic acid level can be elevated by nitrogen. Nitric oxide signals constitute an important part of nitrogen mediated defense mechanisms. Nitric oxide signaling is related to many aspects of plant immunity. The roles of nitrogen fertilizers in CMM stress resistance are complex and may vary with different CMM varieties and environments. Further studies are urgently needed to provide a comprehensive understanding of how to improve stress resistance of CMM by using fertilizers.


Subject(s)
Abscisic Acid , China , Materia Medica , Nitrogen , Plant Growth Regulators
12.
Article in Chinese | WPRIM | ID: wpr-879107

ABSTRACT

Nitrogen is one of the most frequently used fertilizers in growth of Chinese medicinal plants(CMP). As in many other ecosystems, CMP ecosystem is also composed of plant-herbivore-natural enemy(tritrophic) interactions. Nitrogen fertilizer influences the growth and reproduction of CMP, and it is also able to heavily shape the ecosystem functions of CMP ecosystem through bottom-up forces. Understanding the specific effects of nitrogen fertilizer towards each trophic level will be beneficial to improve the resistance of CMP to herbivore and enhance the control efficiency of nature enemies to herbivore, and eventually, maximize the yield and quality of CMP. Most papers published on nitrogen use in plants focused mainly on the impact of nitrogen fertilization on CMP yield and quality. Influences of nitrogen application on CMP ecosystem get little attention at present. Therefore, this review summed up the potential effects of nitrogen fertilization on CMP ecosystem from perspectives of soil and tritrophic interactions. First of all, nitrogen fertilizer might decrease soil microbial biomass and altered the community structures of soil bacteria, fungi and protozoa. Negative effects of nitrogen fertilizer were found on biodiversity of soil bacteria and protozoa. Different fungi species respond differently to nitrogen fertili-zers. Nitrogen deposition can also decrease the soil pH. Decreases in soil microbial diversity and soil acidification can cause negative effects on CMP growth. In addition, nitrogen fertilizer could regulate the pest resistance of CMP including constitutive and inducible resistance. Both positive and negative effects of nitrogen application were found on pest resistance of CMP. Moreover, the development and predation of natural enemies were influenced by nitrogen deposition. Nitrogen influences natural enemies in many ways including plant volatiles, plant nutrient and structure and the supplementary food quality. Nectar and honeydew of plants and preys serve as important food source for natural enemies especially in early season when preys are still not available. Finally, the interactions between herbivores and their natural enemies were also shaped by nitrogen fertilizer in many aspects like increasing the nutritional content of prey and changing control efficiency of natural enemies. Some herbivores have evolved a strategy to sequester secondary metabolites which they absorbed from plant during their feeding. Studies showed that sequestration efficiency of secondary metabolites in prey could also be regulated by nitrogen. Parasitic, emergence, reproduction rate and longevity of parasites were found positively correlated with nitrogen deposition. Hopefully this study will shed light on practicable and economical application of nitrogen in cultivation of CMP.


Subject(s)
China , Ecosystem , Fertilizers , Nitrogen , Plants, Medicinal , Soil
13.
Article in Chinese | WPRIM | ID: wpr-879106

ABSTRACT

Nitrogen fertilizer has been the long-lasting crucial component in cultivation of Chinese materia medica(CMM) and crops for its profound effects on enhancing the productivity. In consideration of its role in better production, intensive and excessive application of N fertilizer is often found in CMM cultivation. Therefore, firstly, this review summarized various concentrations of N application with regards to different CMM and districts from the literatures published in the last two decades. The recommended concentration of nitrogen application of forty seven CMM species were covered in this review. We found that the optimum rates of nitrogen fertili-zer for different medicinal plants species were varied in the range between 0-1 035.55 kg·hm~(-2). Most of the optimum rates of nitrogen fertilizer for CMM in published researches fell between 100-199 kg·hm~(-2). The optimum rate of nitrogen fertilizer is not only related to amount of nitrogen required for different medicinal plants but also to soil fertilities of different fields. In addition, we outlined the diffe-rent effects of proper and excessive nitrogen deposition on yield of CMM. Proper nitrogen deposition benefits the yield of CMM, howe-ver, excessive nitrogen use accounts for a decrease in CMM yield. We elucidated that nutritional content, water use efficiencies, and photosynthesis capacity were major influencing factors. Researches showed that proper nitrogen fertilizer could promote the water use efficiencies of plants and boost photosynthesis. Consequently, the yield of CMM can be enhanced after nitrogen deposition. However, negative effects of nitrogen fertilizer were also found on plant including producing toxic substances to the soil and causing severe pest damages. Lastly we analyzed the impact of N fertilizer application on secondary metabolites which accounts for a large part of active pharmaceutical ingredients of CMM. It usually caused an increase in nitrogen-containing secondary metabolites content and a decrease in non-nitrogen-containing secondary metabolites content respectively. The potential underlying mechanisms are the different synthetic pathways of these metabolites and the plant nutritional status. Synthesis of non-nitrogen-containing secondary metabolites like phenols can be inhibited after nitrogen application because of the competition of the same precursor substances between metabolites synthesis and plant growth. To sum up, impacts and mechanisms of nitrogen fertilizer on yield and quality enhancement of CMM were discussed in this review. Negative effects of excessive nitrogen application on CMM should be paid special attention in CMM cultivation and prescription fertilization based on the field soil quality is strongly recommended. Overall, this review aims to provides insights on improving the proper application of N fertilizer in the cultivation of CMM.


Subject(s)
Agriculture , China , Fertilizers , Materia Medica , Nitrogen/analysis , Soil
14.
Biosci. j. (Online) ; 36(6): 1858-1866, 01-11-2020. ilus, tab, graf
Article in English | LILACS | ID: biblio-1147947

ABSTRACT

Slow-release liquid nitrogen fertilizer sources have been around since 1970. However, this technique is not widely used in the field, probably due to the low cost per ton of nitrogen in the solid form. This study aimed to evaluate the combination of the conventional and slow-release nitrogen fertilization on the yield and phenological variables in a narrow-row cotton crop. Treatments consisted of the combination of the nitrogen fertilizer applied as topdressing in solid form (via soil) and pulverized in the liquid form (via urea formaldehyde - UF): 0% of solid N + 0% of liquid N (0S0L); 100% of solid N + 0% of liquid N (100S0L); 75% of solid N + 25% of liquid N (75S25L); 50% of solid N + 50% of liquid N (50S50L); 25% of solid N + 75% of liquid N (25S75L); e 0% of solid N + 100% of liquid N (0S100L). The cotton crop was phenotypically evaluated at 35, 70, and 130 DAE (Days after emergence) and at the harvest time. The variation between the source of the solid nitrogen fertilizer applied to the soil (ammonium nitrate) and the liquid Nitrogen fertilizer applied by spraying (UF) affects the phenology, physiology, and yield components of the narrow-row cotton crop. The highest yield of the narrow-row cotton crop under the experimental conditions was achieved when 25% of the dose of the solid nitrogen fertilizer was applied as topdressing via soil, and 75% of the dose of the slow-release nitrogen fertilizer was sprayed. This technique provides higher profitability of the produced cotton in relation to the conventional application of the N solid fertilizer via soil.


Fontes de fertilizantes nitrogenados líquidos de liberação lenta existem desde 1970. No entanto, esta técnica não é amplamente utilizada no campo, provavelmente devido ao baixo custo por tonelada de nitrogênio na forma sólida. Este trabalho teve como objetivo avaliar a combinação da adubação nitrogenada convencional e de liberação lenta sobre a produtividade e as variáveis fenológicas em uma cultura de algodão de fileira estreita. Os tratamentos consistiram da combinação do fertilizante nitrogenado aplicado como cobertura na forma sólida (via solo) e pulverizado na forma líquida (via uréia formaldeído - UF): 0% de N sólido + 0% de N líquido (0S0L); 100% de N sólido + 0% de N líquido (100 S); 75% de N sólido + 25% de N líquido (75S25L); 50% de N sólido + 50% de N líquido (50S50L); 25% de N sólido + 75% de N líquido (25S75L); e 0% de N sólido + 100% de N líquido (0S100L). A cultura do algodão foi avaliada fenotipicamente aos 35, 70 e 130 DAE (dias após a emergência) e no momento da colheita. A variação entre a fonte de adubação nitrogenada aplicada ao solo (nitrato de amônio) e o fertilizante nitrogenado líquido aplicado por pulverização (UF) afeta os componentes fenológicos, fisiológicos e produtivos da cultura de algodão de fileiras estreitas. O maior rendimento da cultura de algodão de linha estreita nas condições experimentais foi alcançado quando 25% da dose do fertilizante de nitrogênio sólido foi aplicado como cobertura de solo via solo, e 75% da dose do fertilizante de nitrogênio de liberação lenta foi pulverizada. Esta técnica proporciona maior rentabilidade do algodão produzido em relação à aplicação convencional do fertilizante N via solo.


Subject(s)
Gossypium , Nitrogen
15.
Biosci. j. (Online) ; 36(6): 1890-1899, 01-11-2020. graf, tab
Article in English | LILACS | ID: biblio-1147953

ABSTRACT

Maize represents one of the most cultivated crops of cereals in the world, being used as a source of grain, silage and biofuel. Nitrogen is very required in the maize crop, making nitrogen fertilization a significant part of the production cost. The objective of this study was to evaluate the response of two sources of N, urea and coated urea of controlled release, regarding the productivity and the cost/benefit ratio in maize for 2nd harvest. The experiment was carried out in the field in soil classified as dystroferric Red Latosol and treatments distributed in experimental plots, following the randomized block design with four replications. The treatments were 40 kg N ha-1 of common urea; 60 kg N ha-1 of common urea; 40 kg N ha-1 of coated urea; 60 kg of N-coated urea and the control without application of N broadcast application in planting. The maize crop responded to the application of nitrogen at planting. However, the use of coated urea did not increase the grain yield in relation to the use of common urea. The economic analysis demonstrated a better efficiency of use of N and the best net revenues with the application of the dose of 40 kg N ha -1 of common urea in the planting of the crop.


O milho representa uma das culturas de cereais mais cultivadas no mundo, sendo utilizado como fonte de grãos, silagem e biocombustível. O nitrogênio é muito necessário na cultura do milho, tornando a fertilização nitrogenada uma parte significativa do custo de produção. Este trabalho teve como objetivo avaliar o fertilizante nitrogenado revestido de liberação controlada para a cultura do milho de 2ª safra. O trabalho foi desenvolvido na Fazenda Estância Maracaju, localizada no município de Maracaju ­ Mato Grosso do Sul. As parcelas experimentais foram constituídas por 48 linhas com espaçamento de 0,5 metros por 1000 metros de comprimento entre si. Como área útil considerou-se as 30 linhas centrais (1,5 ha). Os tratamentos utilizados foram T1: 40 kg ha-1 de N de ureia comum; T2: 60 kg ha-1 de N de ureia comum; T3: 40 kg ha-1 de N de ureia revestida; T4: 60 kg de N de ureia revestida e T5: sem aplicação de N. Os tratamentos foram distribuídos nas unidades experimentais segundo delineamento de blocos ao acaso com quatro repetições. A cultura de milho, respondeu aplicação de nitrogênio no plantio. O uso de ureia revestida não influenciou na produtividade de grãos em relação a ureia comum no milho de 2ª safra. A melhor eficiência de uso de N e a melhor receita líquida é com a dose de 40 kg de N ureia ha-1, de ureia comum aplicado no plantio da cultura.


Subject(s)
Zea mays , Nitrogen
16.
Biosci. j. (Online) ; 36(6): 1900-1910, 01-11-2020. graf, tab
Article in English | LILACS | ID: biblio-1147954

ABSTRACT

Studies that demonstrate the effects of sources of nitrogen (N) applied before or after irrigation on the yield of winter crops are limited in literature. In this sense, the objective of this study was to compare the effect of sources of N applied immediately before or after 13 mm irrigation of wheat and bean winter crops. It was used a randomized complete block design, with 4 replicates, in a 5 × 2 + 1 factorial scheme, and 11 treatments consisted of five N sources: urea, polymer-coated urea, urea + ammonium sulfate, ammonium sulfate, and ammonium nitrate and a control treatment (without N fertilization). For wheat, although ammonium nitrate provided great N content in the leaves, the grain yield was lower due to the lodging of the plants; since the application of N either before or after irrigation did not influence the grain yield. Regarding the bean, N fertilization increased productivity, but there were no differences among N sources and, despite the greater N content in the leaves observed with the N supply before irrigation the greatest grain yield was observed when N was applied after the irrigation.


Estudos que demonstram os efeitos de fontes de nitrogênio (N) aplicadas antes ou após a irrigação na produtividade das culturas de inverno são limitados na literatura. Neste sentido, o objetivo deste trabalho foi comparar o efeito de fontes de N aplicadas imediatamente antes ou após a irrigação de 13 mm nas culturas do trigo e feijão de inverno. Utilizou-se o delineamento de blocos casualizados, com 4 repetições, em esquema fatorial incompleto 5 × 2 + 1, sendo 11 tratamentos com cinco fontes de N: ureia, ureia revestida com polímero, ureia + sulfato de amônio, sulfato de amônio e nitrato de amônio e um tratamento controle (sem adubação nitrogenada). Para o trigo, embora o nitrato de amônio tenha proporcionado maior teor de N nas folhas, a produtividade de grãos foi menor devido ao acamamento das plantas; já a aplicação de N antes ou após a irrigação não influenciou a produtividade de grãos. Com relação ao feijão, a adubação nitrogenada aumentou a produtividade, mas não houve diferenças entre as fontes de N e, apesar do maior teor de N nas folhas observadas com o suprimento de N antes da irrigação, a maior produtividade de grãos foi observada com a adubação após a irrigação.


Subject(s)
Polymers , Triticum , Phaseolus , Nitrogen
17.
Biosci. j. (Online) ; 36(6): 1938-1950, 01-11-2020. tab, graf
Article in English | LILACS | ID: biblio-1147958

ABSTRACT

Sunflower is one of the most important oilseeds in the world. However, cultivation in semi-arid regions requires analysis of production costs and profitability, ensuring effective decision-making, focused on farming procedures and techniques. In two agricultural crops, 2016 and 2017, experiments were conducted to evaluate the economic indicators of sunflower cultivars ('Aguará 06', 'Altis 99', 'Multissol' and 'BRS 122') submitted to nitrogen (N) doses (0; 30; 60; 90 and 120 kg ha-1) via fertirrigation under semi-arid conditions. The net margin corresponded to the increase of N doses, reaching a maximum net margin in the 2016 harvest of R$ 366.89 ha-1 at the dose of 81 kg ha-1 of N for 'BRS 122'; R$ 577.41 ha-1 with 118 kg ha-1 of N for 'Multissol'; and for 'Aguará 06' (R$ 2,124.00 ha-1) and 'Altis 99' (R$ 976.66 ha-1) at the dose of 120 kg ha-1 of N. In the 2017 harvest, 'BRS 122' obtained R$ 190.90 ha-1 in the dose of 83 kg ha-1 of N and 'Multissol' reached R$ 657.50 in the dose of 85 kg ha-1 of N; the cultivars 'Aguará 06' (R$ 1,078.00 ha-1) and 'Altis 99' (R$ 957.14 ha-1) in the dose of 120 kg ha-1 of N. The rate of return and the profitability index were positive for all cultivars in both crops.


O girassol é uma das mais importantes oleaginosas do mundo. No entanto, o cultivo em regiões semiáridas requer análise dos custos de produção e rentabilidade, garantindo tomadas de decisão eficazes, focadas em procedimentos e técnicas agrícolas. Em duas safras agrícolas, 2016 e 2017, foram conduzidos experimentos para avaliar os indicadores econômicos de cultivares de girassol ('Aguará 06', 'Altis 99', 'Multissol' e 'BRS 122') submetidos a doses de nitrogênio (N) (0; 30; 60; 90 e 120 kg ha-1) via fertirrigação em condições semiáridas. A margem líquida correspondeu ao aumento das doses de N, atingindo uma margem líquida máxima na safra 2016 de R$ 366,89 ha-1 na dose de 81 kg ha-1 de N para 'BRS 122'; R$ 577,41 ha-1 com 118 kg ha-1 de N para 'Multissol'; e para 'Aguará 06' (R$ 2.124,00 ha-1) e 'Altis 99' (R$ 976,66 ha-1) na dose de 120 kg ha-1 de N. Na safra de 2017, 'BRS 122' obteve R$ 190,90 ha-1 na dose de 83 kg ha-1 de N e 'Multissol' alcançaram R$ 657,50 na dose de 85 kg ha-1 de N; as cultivares 'Aguará 06' (R$ 1.078,00 ha-1) e 'Altis 99' (R$ 957,14 ha-1) na dose de 120 kg ha-1 de N. A taxa de retorno e o índice de lucratividade foram positivos para todas as cultivares em ambas as culturas.


Subject(s)
Helianthus , Nitrogen
18.
Biosci. j. (Online) ; 36(5): 1590-1599, 01-09-2020. tab, ilus
Article in English | LILACS | ID: biblio-1147825

ABSTRACT

The aim of this study was to identify and categorize new bean cultivars regarding their efficiency and responsiveness to nitrogen, phosphorus, and potassium, both individually and simultaneously, as well as to stipulate the cultivars that would suit each niche market based on this classification. Three experiments were conducted in the field separated by nutrients adopting the randomized block design in a factorial scheme (11 x 4) of 11 cultivars in four doses with three replications. Grain yield was the variable investigated and the means were the basis for the classification separated by in four availabilities: low, partial, adequate dose, and nutritional excess. Genetic variability was observed among the bean cultivars for efficiency and responsiveness (agronomic efficiency) to nitrogen, phosphorus, and potassium. The following cultivars: BRS Agreste, BRS Estilo, BRS Notável, and Pérola revealed the greatest values of efficiency and responsive ratings for nitrogen, phosphorus, and potassium, with indications for low and high technological levels. On the contrary, the cultivars BRS Ametista and BRS Sublime based on the efficiency and non-responsive classification showed a low ability to acquire or utilize the nutrients for grain formation. The BRS Pontal cultivar for all three nutrients displayed a high degree of efficiency with a value exceeding the average under different conditions of stress, suggesting that a more rustic cultivar best suits the market niche of small farmers.


O objetivo do trabalho foi identificar e classificar novas cultivares de feijoeiro quanto a eficiência e responsividade ao nitrogênio, fósforo e potássio, de forma individual e simultânea, além de indicar as cultivares para cada nicho de mercado, de acordo com essa classificação. Foram realizados três experimentos em campo, separados por nutriente, com delineamento de blocos casualizados, em esquema fatorial (11 x 4), sendo 11 cultivares em quatro doses, com três repetições. A variável analisada foi a produtividade de grãos e as médias utilizadas para a classificação, separando-se por nutriente, em quatro disponibilidades, sendo baixo, parcial, dose adequada e excesso nutricional. Existe variabilidade genética para eficiência e responsividade (eficiência agronômica) entre os cultivares de feijão, para nitrogênio, fósforo e potássio. As cultivares BRS Agreste, BRS Estilo, BRS Notável e a Pérola são as que possuem maior número de classificações eficientes e responsivas para nitrogênio, fósforo e potássio, sendo indicadas para baixo e alto nível tecnológico. Em sentido oposto, as cultivares BRS Ametista e a BRS Sublime com classificação ineficiente e não-responsiva, com baixa capacidade de adquirir ou utilizar os nutrientes para a formação de grãos. A cultivar BRS Pontal para nitrogênio, fósforo e potássio, apresenta uma eficiência alta ou acima da média sob os diferentes estresses, o que indica que é uma cultivar mais rústica e que atende o nicho de mercado de pequenos produtores.


Subject(s)
Phosphorus , Potassium , Phaseolus , Nitrogen
19.
Biosci. j. (Online) ; 36(5): 1498-1506, 01-09-2020. tab
Article in English | LILACS | ID: biblio-1147328

ABSTRACT

The aim of this study was to evaluate the effect of ammoniation by urea on the nutritional value of elephant grass hay harvested after flowering. A completely randomized design, in double factorial designs with an additional treatment: 4 urea doses (2, 4, 6 and 8%) x 2 treatment periods (30 and 45 days) + 1 (Control) with four replicates each, was employed. Dry matter, ash, ether extract, neutral detergent fiber, acid detergent fiber, cellulose, lignin, neutral detergent fiber corrected for the ash and the protein, total nitrogen, acid detergent insoluble nitrogen, neutral detergent insoluble nitrogen, non-protein nitrogen, in vitro gas production and carbohydrates fractionation were analyzed. The treatments influenced the contents of DM, EE, NDF, ADF, lignin, cellulose, NDFap, fraction A + B1, fraction B2, fraction C, TN, NPN, ADIN, NDIN, L and Vf2. There was a positive linear effect of urea dose for NDF, ADIN, NDIN and L, positive linear effect on fraction A + B1, NT and NPN, and positive quadratic effect for Vf2, with absolute maximum point of 4.5%. Elephant grass hay harvested after flowering has its nutritional value improved, with a minimum dose of 4.5% urea on a dry matter basis.(AU)


Objetivou-se avaliar o efeito da amonização com ureia sobre o valor nutritivo do feno de capim elefante colheitado após florescimento. O estudo foi delineado, em esquema fatorial duplo com um tratamento adicional: 4 doses de ureia (2, 4, 6 e 8%) x 2 período de tratamento (30 e 45 dias) + 1 tratamento controle, com 4 repetições cada. As variáveis analisadas foram: matéria seca (MS), cinzas, extrato etéreo (EE), fibra em detergente neutro (FDN) e ácido (FDA), FDN corrigida para cinzas e proteínas (FDNcp), celulose, lignina, nitrogênio total (NT), nitrogênio insolúvel em detergente ácido (NIDA) e neutro (NIDN), nitrogênio não proteico (NNP). Produção de gases in vitro proveniente dos carboidratos não fibrosos (Vf1) e fibrosos (Vf2), taxa de fermentação dos carboidratos não fibrosos (k1) e fibrosos (k2) e tempo de colonização bacteriana do substrato (L), além do fracionamento de carboidratos. Os tratamentos influenciaram os teores de MS, EE, FDN, FDA, lignina, celulose, FDNcp, fração A + B1, fração B2, fração C dos carboidratos, NT, NNP, NIDA, NIDN, L e Vf2. Houve efeito linear decrescente de dose de ureia para FDNcp, NIDA, NIDN e L, crescente para fração A+B1, NT e NNP, e, quadrático crescente de dose de ureia para Vf2, com ponto máximo absoluto de 4,5% de ureia obtido após derivar a equação de regressão aos 45 dias de tratamento do feno. Concluindo que feno de capim elefante colheitado após florescimento tem seu valor nutricional melhorado, com dose mínima de 4,5% de ureia em base da matéria seca.(AU)


Subject(s)
Urea , Pennisetum , Nutritive Value , In Vitro Techniques , Carbohydrates , Gases , Nitrogen
20.
Arq. bras. med. vet. zootec. (Online) ; 72(4): 1469-1478, July-Aug. 2020. tab
Article in English | LILACS, VETINDEX | ID: biblio-1131483

ABSTRACT

The objective of this study was to evaluate the different lactation stages of F1 Holstein x Zebu cows on intake and digestibility of nutrients, nitrogen use efficiency, feeding behavior and performance. Thirty-six F1 Holstein × Zebu cows with initial body weight (BW) of 482±43kg were used. The early, mid and late lactation stages were characterized after 50±13, 111.5±11.75 and 183.0±17.5 days in milk, respectively. A completely randomized design with three lactation stages and 12 cows in each treatment group was used. Dry matter intake (P=0.01) was higher in late lactation. Milk yield (P<0.01) was 24.17% higher in early lactation than in other stages. Body weight was lowest in mid-lactation cows (465.63kg; P<0.01). The feed efficiency was 23.36% higher in early lactation than in other stages (0.82kg of milk/kg of DM). F1 Holstein x Zebu cows have increased dry matter intake in late lactation. Milk yield and feed efficiency in early lactation were benefited by changes in feeding behavior, such as increased rumination time.(AU)


O objetivo deste estudo foi avaliar os diferentes estágios de lactação de vacas F1 Holandês x Zebu quanto ao consumo e à digestibilidade de nutrientes, à eficiência no uso de nitrogênio, ao comportamento ingestivo e ao desempenho. Trinta e seis vacas F1 Holandês × Zebu, com peso corporal inicial (PC) de 482±43kg, foram utilizadas. Os estágios inicial, médio e final da lactação foram caracterizados após 50±13, 111,5±11,75 e 183,0±17,5 dias de lactação, respectivamente. O arranjo experimental adotado foi o delineamento inteiramente ao acaso, com três fases de lactação e 12 vacas em cada grupo de tratamento. O consumo de matéria seca (P=0,01) foi maior no período final da lactação. Na fase inicial da lactação, a produção de leite (P<0,01) foi maior em 24,17% em comparação às demais fases. Na fase intermediária da lactação, as vacas apresentaram menor peso corporal (465,63kg; P<0,01) em relação às demais fases. A eficiência alimentar foi maior em 23,36% na fase inicial da lactação (0,82kg de leite/kg de MS). Vacas F1 Holandês x Zebu aumentam o consumo de matéria seca no período final da lactação. A produção de leite e a eficiência alimentar no início da lactação foram favorecidas por mudanças no comportamento ingestivo, como o aumento do tempo de ruminação.(AU)


Subject(s)
Animals , Female , Cattle , Nutrients , Feeding Behavior , Nitrogen/administration & dosage , Lactation , Crosses, Genetic
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