Evaluation of pasture soil productivity in the semi-arid zone of Brazil by microbial analyses

Luna, Rômulo Gil de; Coutinho, Henrique Douglas Melo; Grisi, Breno Machado

doi:10.1590/s1517-83822008000300001

Cited by 5 publications

(4 citation statements)

References 23 publications

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“…Anderson & Domsch (1993) proposed the utilization of the qCO 2 to estimate the efficiency of substrate use by soil organisms. The qCO 2 was lowest in forest and pasture soils, in agreement with Luna et al (2008), who reported that the qCO 2 decreases in more stable agroecosystems. These values were different compared with cultivated and capoeira soils; the qCO 2 increased 350 % in the cultivated area compared with the forest area.…”

Section: Br Mbc and Qcosupporting

confidence: 91%

Humic Haplustox under different land uses in a high altitude environment in the Agreste region of Pernambuco, Brazil

Araújo

Ribeiro

Corrêa

et al. 2014

Rev. Bras. Ciênc. Solo

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SUMMARYThe Garanhuns Plateau in the Agreste region of the State of Pernambuco, Brazil is characterized by humid climatic conditions due to orographic rains, unlike the surrounding semiarid region. These soils are subjected to intense agricultural use and are extremely important for the regional economy. This study was carried out in the municipality of Brejão in the Agreste region with the aim of assessing changes in humic Haplustox soils subjected to different land uses. Four plots with different vegetation covers (native forest, secondary shrubby vegetation (capoeira), traditional cropping system, and planted pasture) were selected, and samples were taken from a soil profile and four small pits surrounding it at each site. Physical and chemical properties were assessed, including aggregate stability, humic organic fractions, and a microbiological evaluation through determination of basal respiration, microbial biomass carbon, and metabolic quotient. The soils under study showed physical and chemical properties typical of a Haplustox, such as low nutrient content, low cation exchange capacity, and high levels of acidity and Al saturation. The total organic carbon (TOC) contents were high regardless of the type of land use. Aggregates < 2 mm were dominant in all the conditions under study. The TOC content was higher in the soil under capoeira, 43.91 g kg -1 on the surface, while 34.36 and 33.43 g kg -1 of TOC were observed in the first layer of forest and pasture soils, respectively. While the microbial biomass C (MBC) was greater than 700 mg kg -1 in the forest and pasture areas (in the 0-5 cm layer), and 588 mg kg -1 in the soil under capoeira, these numbers were not statistically different. In the cultivated soil area, there was a reduction of around 28 % in TOC and MBC contents. Agricultural activity contributed to degradation of the humic 1338 horizon, as can be seen from a significant decrease in the TOC and changes in the relative distribution of the humic fractions. In contrast, aggregate stability was not altered as a function of the different land uses; the soil under planted pasture and capoeira were similar to the soil under native forest. Humin was the most important humified fraction for C reserves, contributing over 40 % of the TOC in these soils.Index terms: land use, highland soils, humic substances, aggregate stability, microbial biomass C. RESUMO: LATOSSOLOS AMARELOS HÚMICOS SOB DIFERENTES TIPOS DE UTILIZAÇÃO EM UM AMBIENTE ALTIMONTANO NO AGRESTE DE PERNAMBUCOO Planalto de Garanhuns, no Agreste de Pernambuco, destaca-se por apresentar características climáticas privilegiadas, favorecidas pelas chuvas orográficas, distinguindose da região semiárida circundante. Essas áreas mais úmidas são conhecidas como "brejos de altitude" e intensamente utilizadas e importantes para a economia regional. Este trabalho foi desenvolvido no município de Brejão, Agreste de Pernambuco, com o objetivo de identificar alterações nos atributos de Latossolos Amarelos Húmicos, submetidos às diferentes formas de uso do s...

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Section: Br Mbc and Qcosupporting

confidence: 91%

Humic Haplustox under different land uses in a high altitude environment in the Agreste region of Pernambuco, Brazil

Araújo

Ribeiro

Corrêa

et al. 2014

Rev. Bras. Ciênc. Solo

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“…During the dry season, the highest q CO 2 rates were recorded with increasing proportions of lead-contaminated soil (Figure 3), which indicates that the ecosystem was under stress. These results show that microbial populations invest most of their energy for maintenance, a typical condition of disturbed environments (21). …”

Section: Resultsmentioning

confidence: 75%

Microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants in lead contaminated soil

Gattai¹,

Pereira²,

Costa³

et al. 2011

Braz. J. Microbiol.

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The goals of this study were to evaluate the microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants (Caesalpinia ferrea, Mimosa tenuiflora and Erythrina velutina) in lead contaminated soil from the semi-arid region of northeastern of Brazil (Belo Jardim, Pernambuco). Dilutions were prepared by adding lead contaminated soil (270 mg Kg-1) to uncontaminated soil (37 mg Pb Kg soil-1) in the proportions of 7.5%, 15%, and 30% (v:v). The increase of lead contamination in the soil negatively influenced the amount of carbon in the microbial biomass of the samples from both the dry and rainy seasons and the metabolic quotient only differed between the collection seasons in the 30% contaminated soil. The average value of the acid phosphatase activity in the dry season was 2.3 times higher than observed during the rainy season. There was no significant difference in the number of glomerospores observed between soils and periods studied. The most probable number of infective propagules was reduced for both seasons due to the excess lead in soil. The mycorrhizal colonization rate was reduced for the three plant species assayed. The inoculation with arbuscular mycorrhizal fungi benefited the growth of Erythrina velutina in lead contaminated soil.

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“…Africa: Venter, Scholes & Eckhardt 2003; AGIS, http://www.agis.agric.za, 3. South America: Furley 1999; Moreira 2000Leal, Wirth & Tabarelli 2007; de Luna, Coutinho & Grisi 2008.…”

Section: Methodsmentioning

confidence: 99%

Biomass partitioning and root morphology of savanna trees across a water gradient

et al. 2012

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Summary 1. Plant organ biomass partitioning has been hypothesized to be driven by resources, such that species from drier environments allocate more biomass to roots than species from wetter environments to access water at greater soil depths. In savanna systems, fire may select for greater allocation to root biomass, especially in humid environments where fire is more frequent. Therefore, species from drier environments may have been under selection pressure to reach deeper soil water more effectively than species from humid environments, through faster root extension, more efficient depth penetration, and faster plant growth rates to respond rapidly to variable rainfall events. 2. We compared biomass partitioning, root morphology traits [root extension rate, RER; specific taproot length (STRL)] and relative growth rate (RGR) of seedlings of 51 savanna tree species, sampled from three continents (Africa, Australia and South America) in a greenhouse experiment. We used phylogenetically corrected and uncorrected analyses to compare the traits of the groups. We conducted a permanova on the combined traits to establish whether species could be distinguished on the basis of their combined traits. 3. On average, species from humid environments allocated more biomass to roots and less to stems than species from semi‐arid environments, consistent with the expectation that fire pressure selects for greater allocation to roots in humid environments. However, some species from humid environments had fast growth rates instead of high allocation to roots. Both RER and STRL were greater among species of semi‐arid environments than among species of humid environments, and also differed between continents. Differences between strategies under each climate type appear to be associated with leaf habit. 4. Synthesis. Plant biomass partitioning has been selected by defoliation pressure and the effects of this selection pressure can supersede any selection in response to local water constraints. Root morphological adaptations, but not plant growth rate, of tree seedlings, have been selected in response to water deficits.

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Evaluation of pasture soil productivity in the semi-arid zone of Brazil by microbial analyses

Cited by 5 publications

References 23 publications

Humic Haplustox under different land uses in a high altitude environment in the Agreste region of Pernambuco, Brazil

Humic Haplustox under different land uses in a high altitude environment in the Agreste region of Pernambuco, Brazil

Microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants in lead contaminated soil

Biomass partitioning and root morphology of savanna trees across a water gradient

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