Energia na Agricultura, Botucatu, v. 39, p. 58-62, 2024 58

Edição especial – VI Workshop de Inovações Tecnológicas na Agricultura - WINOTEC

ISSN 2359-6562 (ONLINE) 2359-6562 (CD- ROM)

INFLUÊNCIA DO RESÍDUO DE LEGUMINOSAS ARBÓREAS NA FITOMASSA DO SORGO

MARCOANTÔNIO ROSADE CARVALHO1, LILIAN CRISTINA CASTRO DE CARVALHO2 , REGINALDO ROSSI LOPES DE MARIA3, SARAH ARAÚJO TEIXEIRA4, INGRID SOLEDADE JERONIMO DE ARAÚJO 5

1Eixo de Recursos Naturais, Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), Campus Sobral, Av. Dr. Guarany, 317, Bairro Derby Clube, CEP 62.042-030, Sobral, Ceará, Brasil, E-mail: marcorosa@ifce.edu.br

2Eixo de Recursos Naturais, Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), Campus Sobral, Av. Dr. Guarany, 317, Bairro Derby Clube, CEP 62.042-030, Sobral, Ceará, Brasil, E-mail: liliancarv@ifce.edu.br

3Eixo de Recursos Naturais, Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), Campus Sobral, Av. Dr. Guarany, 317, Bairro Derby Clube, CEP 62.042-030, Sobral, Ceará, Brasil, E-mail: reginaldorossi_93@hotmail.com

4Eixo de Recursos Naturais, Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), Campus Sobral, Av. Dr. Guarany, 317, Bairro Derby Clube, CEP 62.042-030, Sobral, Ceará, Brasil, E-mail: sarah.araujo60@aluno.ifce.edu.br

5Eixo de Recursos Naturais, Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), Campus Sobral, Av. Dr. Guarany, 317, Bairro Derby Clube, CEP 62.042-030, Sobral, Ceará, Brasil, E- mail: ingrid.soledade.jeronimo45@aluno.ifce.edu.br

RESUMO: Este estudo teve o objetivo de avaliar a interação entre leguminosas arbóreas e a cultura do sorgo cultivado em solo degradado no município de Sobral-CE. O experimento foi conduzido nas instalações de uma casa de vegetação localizada no Instituto Federal de Educação, Ciência e Tecnologia do Ceará – IFCE, Campus Sobral, região noroeste do estado. O delineamento experimental adotado foi o de blocos ao acaso, com dez tratamentos e quatro repetições, totalizando quarenta parcelas experimentais. Foram avaliados os seguintes tratamentos: 1) Folhas de Leucaena Leucocephala, 2) Galhos de Leucaena Leucocephala, 3) Folhas + galhos de Leucaena Leucocephala, 4) Folhas de Mimosa hostilis, 5) Galhos de Mimosa hostilis, 6) Folhas + galhos de Mimosa hostilis, 7) Folhas de Mimosa caesalpiniifolia, 8) Galhos de Mimosa caesalpiniifolia, 9) Folhas + galhos de Mimosa caesalpiniifolia e 10) Sem resíduo de leguminosas. Cada parcela experimental foi representada por um vaso plástico com capacidade de 10 dm3 de substrato, contendo três plantas. Foram feitas as seguintes avaliações: matéria seca da parte aérea no primeiro corte e no segundo corte (rebrota). Os dados para cada variável estudada foram submetidos à análise de variância sendo as médias comparadas pelo teste de Tukey a 5%.

Palavras-chave: qualidade do solo; adubação verde; matéria orgânica .

INFLUENCE OF LEGUME TREE RESIDUAL IN PHYTOMASS OF SORGHUM

ABSTRACT: This study aimed to evaluate the interaction between leguminous trees and sorghum grown on degraded soil at Sobral-CE. The experiment was conducted on the premises of a greenhouse located at the Federal Institute of Education, Science and Technology of Ceará - IFCE Campus Sobral, Northwest Region in the state. The experimental design was a randomized block with ten treatments and four replications, totaling forty plots. We evaluated the following treatments: 1) Leaves of Leucaena leucocephala, 2) branches of Leucaena leucocephala, 3) leaves + branches of Leucaena leucocephala , 4) leaves of Mimosa hostilis, 5) branches of Mimosa hostilis, 6) leaves + branches of Mimosa hostilis, 7) leaves of Mimosa caesalpiniifolia, 8) branches of Mimosa caesalpiniifolia, 9) leaves + branches of Mimosa caesalpiniifolia and 10) no residue of leguminous plants. Each plot was represented by a plastic vase with a capacity of 10 dm3 of substrate containing three plants. The participants were asked the following ratings: the aboveground part of the first cut and the second cut (regrowth). The data for each variable were subjected to analysis of variance, and the means were compared via Tukey’s test at 5%.

Recebido em 03/12/2024 e aprovado para publicação em 12/12 /2024

DOI: http://dx.doi.org/10.17224/EnergAgric.2024v39p58- 62

59 Carvalho et al./Influência do resíduo.../v39p58-62 (2024)

Keywords: soil quality, green manure, organic matter. 1 INTRODUCTION

Species of the legume family can add large amounts of organic matter and nitrogen (N) to the soil through litter in a relatively short time, favoring nutrient cycling and the rehabilitation process (Chaer et al., 2011).

Knowledge of the interactions between legumes and annual crops is highly important for the management of agroforestry systems, since legumes establish symbiotic relationships with nitrogen-fixing bacteria and serve as mulch and green manure (Santos et al., 2010).

Among the desirable characteristics for selecting cover species, the production of phytomass and the capacity to accumulate N through biological fixation or absorption of nutrients in the soil stand out. These attributes, together with the C/N ratio of the straw, allow estimation of the potential of cover crops to increase the supply of N for subsequent crops (Oliveira; Carvalho; Moraes, 2002; Boer et al ., 2007).

The thrush (Mimosa caesalphiifolia Benth.) is a woody species of the Caatinga in Northeast China and is well known for being a tree that is used for various purposes, such as wood, forage, stakes, and honey production. It is one of the most suitable species for use in agroforestry systems, as it has fast growth, good protein and energy value, high regrowth power and resistance to drought (Carvalho; Garcia; Araujo Filho, 2004).

Black jurema (Mimosa hostilis) Benth.), a legume found in almost the entire northeast region, has a high capacity for drought tolerance and good growth in shallow soils and is one of the pioneer species in degraded areas. This species has a shrubby appearance and a forked trunk, and after five years, it has reached an average height of 4.5 meters (Lima, 1996).

Leucaena (Leucaena leucocephala) has a wide geographic distribution and grows in regions with rainfall ranging from 600 mm to 1,700 mmper year. However, it can also be found

in drier areas, with rainfall of approximately 250 mm. It can withstand periods of drought lasting more than eight months and an annual water deficit of up to 870 mm. It is restricted to the tropics and subtropics, with temperatures between 10 °C and 40 °C. It is a shrubby tree, with a height of up to 20 m and a diameter at breast height (DBH) of up to 30 cm (Drumond; Ribaski, 2010).

This study aimed to evaluate the interaction between the plant residue of leguminous trees and sorghum crops grown in degraded soil.

2 MATERIALS AND METHODS

The experiment was conducted in the facilities of an agricultural screen located at the Federal Institute of Education, Science and Technology of Ceará - IFCE/Sobral Campus in the municipality of Sobral - CE. The geographic coordinates of the region where the experiment was installed are 3° 41' South latitude, 40° 20' West longitude and an average altitude of 70 m. The substrate used to fill the pots was degraded soil without any fertilization. The plant residue that constituted the treatments was collected directly from the plants in the vicinity of the experimental site.

Sorghum bicolor L. Moench) seeds were planted in trays on January 27, 2014, and the seedlings were subsequently transplanted into pots on February 10, 2014. The legume residue was applied as mulch; after drying in an oven and grinding in a knife mill, it was applied on March 20, 2014, with a standardized weight of 76 g for each pot. On June 10, 2014, the aerial part was harvested and placed in an oven immediately afterward to determine dry matter. On July 14, the aerial part of the regrowth was harvested an d immediately taken to the oven to determine dry matter.

Irrigation management was based on daily readings from a Class A tank installed inside the screen, with the irrigation depth equal

Carvalho et al./Influência do resíduo.../v39p58-62 (2024) 60

to 100% of the evaporated depth. Seedling thinning was performed 10 days after emergence, and the three most vigorous plants were left in each pot.

The experimental design adopted was randomized blocks, with ten treatments and four repetitions, totaling forty experimental plots. The following treatments were evaluated: 1) Leaves of Leucaena leucocephala, 2) Leucaena leucocephala twigs, 3) Leucaena leucocephala leaves + twigs, 4) Mimosa hostilis leaves, 5) Mimosa hostilis twigs, 6) Mimosa hostilis leaves + twigs, 7) Mimosa caesalpiniifolia leaves, 8) Branches of Mimosa caesalpiniifolia, 9) Leaves + twigs of Mimosa caesalpiniifolia and 10) no legume residue. Each experimental plot was represented by a plastic pot with a substrate capacity of 10 dm3, which contained three plants. To quantify the sorghum phytomass, the

aerial part dry matter (MSP) and the regrowth dry matter (MSR) were determined. The plants (stems and leaves) were collected and fractionated with the aid of pruning shears, placed in previously identified paper bags, and

then placed to dry in an air circulation and renewal oven at 65 °C until they reached a constant weight. Then, the aerial dry matter was determined on a precision digital scale (0.01 g). Statistical analyses were performed according to the criteria established by experimental statistics (Ferreira, 2000). In these analyses, EXCEL spreadsheets were used in the analysis of variance; treatments were compared via the F test, considering a minimum significance level of 1% probability. Comparisons between means were performed via the Tukey test at the 5% probability level .

3 RESULTS AND DISCUSSION

The “no coverage” treatment presented the lowest MSP, and the best MSP performance was from the “Leucena leaves” treatment.

The results of the analysis of variance revealed that there was a significant difference at the 1% probability level between the treatments , and there was no significant difference at the 5% probability level for the blocks (Table 1).

Table 1. Analysis of variance of the effects of tree legume residues on the dry matter of the aerial parts of sorghum plants (in g).

Cause of variation GL SQ QM F

Treatments 9 63974.49 7108.27664 50.69 **

Blocks 3 44.39 14.79516 0.11 ns

Residue 27 3786.52 140.24152

Total 39 67805.40

ns: Not significant at the 5% probability level. **: Significant at the 1% probability level.

The coefficient of variation of the dry matter in the aerial part of the experiment was 21.31%. To compare the means of the treatments,

the Tukey test was performed at the 5% probability level (Table 2).

61 Carvalho et al./Influência do resíduo.../v39p58-62 (2024)

Table 2. Comparison of the dry matter of the aerial parts of sorghum plants (in g) among the ten treatments.

Treatments Treatment averages

No coverage 8.21 a

Branches of Thrush 11.83 a

Jurema branches 16.39 ab

Leucaena branches 31.53 ab

Jurema leaves and branches 41.81 b

Sabiá leaves and branches 44.09 b

Leucaena leaves and twigs 79.51c

Jurema Leaves 88.46c

Sabia Leaves 107.02 cd

Leucaena Leaves 127.00 d

Treatment means with the same letter do not differ from each other according to the Tukey test at the 5% probability level.

The “Jurema branches” treatment presented the lowest MSR, and the best MSR performance was from the “Leucena leaves” treatment.

The results of the analysis of variance revealed that there was a significant difference at the 1% probability level between the treatments , and there was no significant difference at the 5% probability level for the blocks (Table 3).

Table 3. Analysis of variance of the effect of tree legume residues on the dry matter of sorghum plant regrowth (in g).

Cause of variation GL SQ QM F

Treatments 9 90.46201 10.05133 8.78 **

Blocks 3 0.71282 0.23761 0.21 ns

Residue 27 30.89553 1,14428

Total 39 122.07036

ns: Not significant at the 5% probability level. **: Significant at the 1% probability level.

The coefficient of variation of the experiment in the analysis of the dry matter of the regrowth was 57.23%. To compare the means of

the treatments, the Tukey test was performed at the 5% probability level (Table 4).

Table 4. Comparison of the dry matter of the regrowth of sorghum plants among the ten treatments.

Treatments Treatment averages

Jurema branches 0.38 to

No coverage 0.42 to

Branches of Thrush 0.53 ab

Leucaena branches 0.73 ab

Jurema leaves and branches 1.29 abc

Sabia Leaves 1.58 abc

Sabiá leaves and branches 2.14 abc

Leucaena leaves and twigs 3.07 bcd

Jurema Leaves 3.37 cd

Leucaena Leaves 5.19 d

Treatment means with the same letter do not differ from each other according to the Tukey test at the 5% probability level.

Carvalho et al./Influência do resíduo.../v39p58-62 (2024) 62

4 CONCLUSIONS

The “no coverage” treatment presented the worst performance in relation to the development of sorghum, closely followed by the treatments with branches.

The treatments with Leucena residue provided the greatest gains in the sorghum crop, with an emphasis on the “Leucena leaves” treatment.

5 REFERENCES

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CARVALHO, F.C.; GARCIA, R.; ARAUJO FILHO, J. A . In situ management of Sabiá

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CHAER, GM RESENDE, AS; CAMPELLO, EFC; FARIA, S.M.; BODDEY, RM Nitrogen -

fixing vegetable tree species for reclamation of severely degraded lands in Brazil. Tree Physiology , Oxford, v. 31, n. 2, p. 139- 149, 2011.

DRUMOND, MA; RIBASKI, J. Leucena

(Leucaena leucocephala): multiple-use legume for the Brazilian semiarid region. Petrolina: Embrapa Semiárido, 2010. (Technical Communication, 262).

FERREIRA, PV Experimental statistics applied to Agronomy . 3rd ed. Maceió: UFAL, 2000.

LIMA, JLS Forage plants of the caatinga : use and potential . Petrolina: EMBRAPA, 1996.

OLIVEIRA, TK; CARVALHO, GJ; MORAES, RNS Cover crops and their effects on common beans in no-tillage. Brazilian Agricultural Research , Brasília, DF, v. 37, p. 1079- 1087, 2002.

SANTOS, CC; SILVA, LG; SILVA, GC; FERRAZ JUNIOR, ASL Allelopathy between leguminous trees and cowpea. Scientia Agraria , Curitiba, v. 11, n. 3, p. 187-192, 2010.