Navegando por Autor "Moura, Waldenia de Melo"

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Biological nitrogen fixation by legumes and n uptake by coffee plants
(Sociedade Brasileira de Ciência do Solo, 2017) Mendonça, Eduardo de Sá; Lima, Paulo Cesar de; Guimarães, Gabriel Pinto; Moura, Waldenia de Melo; Andrade, Felipe Vaz
Green manures are an alternative for substituting or supplementing mineral nitrogen fertilizers. The aim of this study was to quantify biological N fixation (BNF) and the N contribution derived from BNF (N-BNF) to N levels in leaves of coffee intercropped with legumes grown on four family farms located in the mountainous region of the Atlantic Forest Biome in the state of Minas Gerais, Brazil. The following green manures were evaluated: pinto peanuts (Arachis pintoi), calopo (Calopogonium mucunoides), crotalaria (Crotalaria spectabilis), Brazilian stylo (Stylosanthes guianensis), pigeon pea (Cajanus cajan), lablab beans (Dolichos lablab), and velvet beans (Stizolobium deeringianum), and spontaneous plants. The experimental design was randomized blocks with a 4 × 8 factorial arrangement (four agricultural properties and eight green manures), and four replications. One hundred grams of fresh matter of each green manure plant were dried in an oven to obtain the dry matter. We then performed chemical and biochemical characterizations and determined the levels of 15 N and 14 N, which were used to quantify BNF through the 15 N (δ 15 N) natural abundance technique. The legumes C. mucunoides, S. guianensis, C. cajan, and D. lablab had the highest rates of BNF, at 46.1, 45.9, 44.4, and 42.9 %, respectively. C. cajan was the legume that contributed the largest amount of N (44.42 kg ha -1 ) via BNF.C. cajan, C. spectabilis, and C. mucunoides transferred 55.8, 48.8, and 48.1 %, respectively, of the N from biological fixation to the coffee plants. The use of legumes intercropped with coffee plants is important in supplying N, as well as in transferring N derived from BNF to nutrition of the coffee plants.
Identification of morphoagronomic traits correlated with the N use efficiency in coffee
(Editora UFLA, 2025-04-29) Moura, Waldenia de Melo; Ribeiro, Poliane Marcele; Soares, Luciana Gomes; Silva Júnior, Antônio Carlos da; Ferreira, Tatiane Cravo; Gravina, Geraldo de Amaral; Martinez, Hermínia Emília Prieto
The study of nutritional efficiency is an expensive process, as it requires extensive planting areas, several years of evaluation and the destruction of plants. To mitigate these difficulties, a strategy would be to identify easily measurable traits associated with nutritional efficiency in growing a nutritional solution. Thus, the objective of this study was identify morphoagronomic traits correlated with the N-efficiency indices in to assist in selecting coffee genotypes for environments with N restriction. Twenty arabica coffee genotypes were grown in a nutrient solution with a low concentration of nitrogen (1.0 mmol L-1). The experiment was conducted in a randomized block design with three replications. There was variability among the coffee genotypes for all the traits evaluated. Most of the traits evaluated showed greater genetic than environmental influence on phenotypic expression. Heritability (H2) was greater than 70% for most of the traits evaluated, with an emphasis on plant height and internode length, which also had the highest relative variation indices (RVIs). The associations between morphoagronomic traits and nutritional efficiency indices revealed greater contributions of genotypic correlation than of environmental correlation. Among the traits associated with nutritional efficiency indices, stem diameter has the potential for use in breeding programs for the selection of cultivars that present greater nitrogen efficiency in environments with nitrogen restriction.
Nutrient release from green manure under different sun-exposed faces
(Editora UFLA, 2018-04) Mendonça, Eduardo de Sá; Moura, Waldenia de Melo; Guimarães, Gabriel Pinto; Burak, Diego Lang
The evaluation of the decomposition of plant residues added to the soil for green manures allows better understanding of the nutrient supply for coffee. The aim of this study was to determine the decomposition constant (κ), the half- lifetime (t 1/2 ) and the nutrient release from legumes and spontaneous plant under two environmental conditions of sun-exposure in the Zona da Mata of Minas Gerais state. The experimental unit located in Araponga has northwest sun-exposure face and the experimental unit located in Pedra Dourada has the south sun-exposure face. The experimental design was a randomized block in a 2 x 8 x 6 factorial (two environments facing sun-exposure, 8 green manures and 6 residue decomposition assessment times), with four replicates. The results showed that κ and t 1/2 of the evaluated green manures did not differ between the northwestern face (highest altitude, temperature and incident light) and the south face (lower altitude, temperature and incident light). The κ difference obtained between all green manures was due to its chemical and biochemical composition. At the end of the evaluation period of 240 days an average of 62,3 and 63,1% N; 99,4 and 99,5% P and 92,8 and 93,3% K were released from the green manures of the northwest and south faces respectively. The most promising legume in the total nutrients release on the northwest face was D. lablab with 74,6; 10,9 and 69,0 kg ha-1 of N, P and K, respectively. To the south face the most promising legume was C. spectabilis with 69,1; 10,4 and 47,9 kg ha-1 of N, P and K, respectively.