scholarly journals Microbial biomass and enzyme activity of a Cerrado Oxisol under agroecological production system

Bragantia ◽  
2011 ◽  
Vol 70 (4) ◽  
pp. 899-907 ◽  
Author(s):  
Enderson Petrônio de Brito Ferreira ◽  
Adriane Wendland ◽  
Agostinho Dirceu Didonet

Aiming to evaluate the effects of soil management and cover crops on microbial indicators of soil quality, an experiment was carried out under field conditions in which common bean and corn were cropped under no-tillage (NT) and conventional tillage (CT) after sunnhemp, velvet bean, pigeon pea, jack bean, sorghum and fallow (weeds). The basal soil respiration (BSR), C and N of the microbial biomass (Cmic and Nmic), metabolic quotient (qCO2), total enzymatic activity (TEA), β-glycosidase (β-GA) activity and acid phosphatase activity (APA) were evaluated in samples collected in 0-0.10 m depth. Cmic, qCO2, TEA, β-GA and APA were more sensitive in determining the effects caused by tillage and cover crops. Although the cover crops had not provided a remarkably influence on the studied indicators, in general, the highest values of Cmic, Nmic, BSR, TEA, β-GA and APA and the lowest values of qCO2 were observed under NT compared to CT. Cmic and TEA values were 35% and 13% higher under NT when compared to CT, respectively. In addition, NT showed values closer to those found under "Cerrado" area for the studied parameters, indicating a greater sustainability under this soil management system compared to CT management.

2020 ◽  
Vol 87 ◽  
Author(s):  
Djavan Pinheiro Santos ◽  
Robélio Leandro Marchão ◽  
Ronny Sobreira Barbosa ◽  
Juvenal Pereira da Silva Junior ◽  
Everaldo Moreira da Silva ◽  
...  

ABSTRACT: The soil macrofauna is fundamental for the maintenance of soil quality. The aim of this study was to characterize the soil macrofauna under different species of cover crops, including monoculture or intercropping associated to two types of soil management in the southwest region of Piauí state. The study was carried out in an Oxisol (Latossolo Amarelo, according to Brazilian Soil Classification System) in the municipality of Bom Jesus, Piauí, distributed in 30 m2 plots. Testing and evaluation of the soil macrofauna were conducted in a 9 × 2 strip factorial design, with combinations between cover crops/consortia and soil management (with or without tillage), with four replications. Soil monoliths (0.25 × 0.25 m) were randomly sampled in each plot for macrofauna at 0‒0.1, 0.1‒0.2, and 0.2‒0.3 m depth, including surface litter. After identification and counting of soil organims, the relative density of each taxon in each depth was determined. The total abundance of soil macrofauna quantified under cover crops in the conventional and no-tillage system was 2,408 ind. m-2, distributed in 6 classes, 16 orders, and 31 families. The results of multivariate analysis show that grass species in sole cropping systems and no-tillage presents higher macrofauna density, in particular the taxonomic group Isoptera. No-tillage also provided higher richness of families, where Coleoptera adult were the second more abundant group in no-tillage and Hemiptera in conventional tillage.


2015 ◽  
Vol 39 (4) ◽  
pp. 1003-1014 ◽  
Author(s):  
Elcio Liborio Balota ◽  
Ines Fumiko Ubukata Yada ◽  
Higo Furlan Amaral ◽  
Andre Shigueyoshi Nakatani ◽  
Mariangela Hungria ◽  
...  

Many forested areas have been converted to intensive agricultural use to satisfy food, fiber, and forage production for a growing world population. There is great interest in evaluating forest conversion to cultivated land because this conversion adversely affects several soil properties. We examined soil microbial, physical, and chemical properties in an Oxisol (Latossolo Vermelho distrófico) of southern Brazil 24 years after forest conversion to a perennial crop with coffee or annual grain crops (maize and soybeans) in conventional tillage or no-tillage. One goal was to determine which soil quality parameters seemed most sensitive to change. A second goal was to test the hypothesis that no-tillage optimized preservation of soil quality indicators in annual cropping systems on converted land. Land use significantly affected microbial biomass and its activity, C and N mineralization, and aggregate stability by depth. Cultivated sites had lower microbial biomass and mineralizable C and N than a forest used as control. The forest and no-tillage sites had higher microbial biomass and mineralizable C and N than the conventional tillage site, and the metabolic quotient was 65 and 43 % lower, respectively. Multivariate analysis of soil microbial properties showed a clear separation among treatments, displaying a gradient from conventional tillage to forest. Although the soil at the coffee site was less disturbed and had a high organic C content, the microbial activity was low, probably due to greater soil acidity and Al toxicity. Under annual cropping, microbial activity in no-tillage was double that of the conventional tillage management. The greater microbial activity in forest and no-tillage sites may be attributed, at least partially, to lower soil disturbance. Reducing soil disturbance is important for soil C sequestration and microbial activity, although control of soil pH and Al toxicity are also essential to maintain the soil microbial activity high.


2016 ◽  
Vol 51 (9) ◽  
pp. 1668-1676 ◽  
Author(s):  
Géssica Pereira de Souza ◽  
Cícero Célio de Figueiredo ◽  
Djalma Martinhão Gomes de Sousa

Abstract The objective of this work was to evaluate the effects of soil management systems, cover crops, and phosphate fertilization on soil humic fractions in a long-term experiment. The treatments consisted of conventional tillage and no-tillage with pearl millet (Pennisetum glaucum) or velvet bean (Mucuna aterrima) as cover crops, at two doses of phosphorous: 0 and 100 kg ha-1 P2O5 per year. Soil samples were taken 11 years after the establishment of the experiment and analyzed for soil total organic carbon and carbon content of humic fractions at 0.00-0.05, 0.05-0.10, and 0.10-0.20-m depths. The humic fractions are sensitive to soil management, except free fulvic acid, which was the only one that did not reduce its carbon contents on the surface layer (0.00-0.05 m) with conventional tillage. The main changes occurred on the soil surface layer, in which the no-tillage system with pearl millet as a cover crop provided the highest carbon levels in humic fractions. Long-term phosphate fertilization under no-tillage, with pearl millet as a cover crop, promotes the accumulation of organic carbon in soil humic fractions.


2003 ◽  
Vol 60 (3) ◽  
pp. 581-586 ◽  
Author(s):  
Ildegardis Bertol ◽  
Eloy Lemos Mello ◽  
Jean Cláudio Guadagnin ◽  
Almir Luis Vedana Zaparolli ◽  
Marcos Roberto Carrafa

Water erosion causes soil degradation, which is closely related to nutrient losses either in, the soluble form or adsorbed to soil particles, depending mainly on the adopted soil management system. This study was carried out in São José do Cerrito, SC, Brazil, between March 2000 and June 2001. The objective was to quantify available nitrogen, phosphorus, potassium, calcium and magnesium losses in water erosion obtained with simulated rainfall in the following soil management systems: conventional tillage with no-crop (bare soil) (BS), conventional tillage with soybean (CT), reduced tillage with soybean (RT), no tillage with soybean on a desiccated and burned natural pasture (DBNP), and no tillage with soybean on a desiccated natural pasture (DNP). A rotating boom rainfall simulator was used to perform three rainfall tests with constant intensity of 64 mm h-1 and sufficient duration to reach constant runoff rate, on a clayey-loam, well-structured Typic Hapludox, with an average slope of 0.18 m m-1. The first test was carried out five days before soybean emergence and the second and third at 30 and 60 days, respectively. The nutrient concentration in water and total losses of nitrogen, phosphorus, potassium, calcium and magnesium were higher under CT than in the other soil management systems.


2018 ◽  
Vol 48 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Orivaldo Arf ◽  
José Roberto Portugal ◽  
Salatiér Buzetti ◽  
Ricardo Antônio Ferreira Rodrigues ◽  
Marco Eustáquio de Sá

ABSTRACT The Brazilian Savannah region presents a great potential for the expansion of upland rice crops. However, studies are necessary to identify practices that can improve the crop performance, especially in no-tillage systems. This study aimed to assess the effect of cover crops in association with corn on the development and yield of rice cultivated in rotation and cover fertilized with nitrogen doses. The sprinkler irrigation system was used and the experiment was developed in the 2014/2015 and 2016/2017 harvest years, using a randomized block design, in a 5 × 4 factorial scheme. The treatments consisted of the crop remains combinations of single corn crop, corn + Crotalaria spectabilis, corn + pigeon pea, corn + jack bean and corn + Urochloa ruziziensis, as well as cover nitrogen doses (0 kg ha-1, 40 kg ha-1, 80 kg ha-1 and 120 kg ha-1) in the rice. The cultivation of upland rice in rotation with corn + pigeon pea was favored by the greater soil cover and nitrogen supply via cycling, if compared to the rotation with single corn crop. The intercropped corn + pigeon pea cultivation in the previous summer resulted in a 15 % increase in the yield of rice grains seeded in the rotation, when compared to the single corn crop. The cover nitrogen application positively influenced the grain yield with the maximum estimated doses of 46 kg ha-1 and 105 kg ha-1 of nitrogen, respectively in the 2014/2015 and 2016/2017 harvest years.


2018 ◽  
Vol 31 (2) ◽  
pp. 264-270 ◽  
Author(s):  
JOÃO LUÍS DA SILVA FILHO ◽  
ANA LUÍZA DIAS COELHO BORIN ◽  
ALEXANDRE CUNHA DE BARCELLOS FERREIRA

ABSTRACT No-tillage cotton systems require soil coverage with cover crop residue for a longer time due to the late cycle of cotton. However, decomposition rates may vary between cover crops, and the adjustment of models to describe it is critical to no-tillage cotton management. Two non-linear regression models, exponential (EM) and Michaelis-Menten (MM), were adjusted to dry matter decomposition of cover crops in a cotton no-tillage system, in Brazil. Three field trials were performed in 2012 for the cover crops Urochloa ruziziensis (brachiaria), Pennisetum glaucum (pearl millet), and Cajanus cajan (pigeon pea). Samples of cover crop were collected at 20, 50, 70, 110, 140, and 170 days after sowing upland cotton to measure dry matter decomposition. MM showed better adjustment than EM for all cover crops. The estimations of half-life parameters were different between the cover crops, suggesting that each cover crop has its own rate of decomposition. For pearl millet, brachiaria, and pigeon pea, the half-life estimation by exponential model was over the MM in 9, 12, and 12 days.


2019 ◽  
Vol 32 (2) ◽  
pp. 295-301
Author(s):  
SIMONE DE MELO SANTANA-GOMES ◽  
CLAUDIA REGINA DIAS-ARIEIRA ◽  
JÚLIO CÉSAR ANTUNES FERREIRA ◽  
RAIANE PEREIRA SCHWENGBER ◽  
SEPHORA SERRANO BALDISERA

ABSTRACT This study aimed to evaluate the reproduction of Pratylenchus zeae and P. brachyurus in leguminous plants used as cover crops. Seedlings of sunn hemp (Crotalaria juncea and C. spectabilis), pigeon pea cultivar IPR 43 (Cajanus cajan), dwarf velvet bean (Mucuna deeringiana), black velvet bean (Stizolobium aterrimum), and jack bean (Canavalia ensiformis) were inoculated with each nematode separately. Maize cultivar IPR 114 and soybean cultivar Pintado were used as controls to measure the viability of the inoculation of P. zeae and P. brachyurus. After 90 days of inoculation, the plants were collected and nematode g-1 root, final population, and reproduction factors (RF) were evaluated. The experiment was carried out at two different times of the year. The nematode’s RF on cover crops from treatments with the two Crotalaria species, dwarf pigeon pea, and black velvet bean were lower than one (bad host plants) in both experiments for P. zeae. For P. brachyurus, the lowest RFs were obtained for C. juncea, C. spectabilis, and pigeon pea, while the other plants presented RF values close to or higher than one in at least one of the experiments. Therefore, C. spectabilis, C. juncea, and C. cajan cultivar IPR 43 are antagonistic plants that represent useful options for rotation or succession systems that aim to control P. zeae and P. brachyurus.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1848
Author(s):  
Otávio A. Leal ◽  
Telmo J. C. Amado ◽  
Jackson E. Fiorin ◽  
Cristiano Keller ◽  
Geovane B. Reimche ◽  
...  

Cover crops (CC), particularly legumes, are key to promote soil carbon (C) sequestration in no-tillage. Nevertheless, the mechanisms regulating this process need further elucidation within a broad comprehensive framework. Therefore, we investigated effects of CC quality: black oat (Avena strigosa Schreb) (oat), common vetch (Vicia sativa L.) (vetch), and oat + vetch on carbon dioxide-C (CO2-C) emission (124 days) under conventional- (CT), minimum- (MT) and no-tillage (NT) plots from a long-term experiment in Southern Brazil. Half-life time (t1/2) of CC residues and the apparent C balance (ACB) were obtained for CT and NT. We linked our data to long-term (22 years) soil C and nitrogen (N) stocks and crop yield data of our experimental field. Compared to CT, NT increased t1/2 of oat, oat + vetch and vetch by 3.9-, 3.1- and 3-fold, respectively; reduced CO2-C emissions in oat, oat + vetch and vetch by 500, 600 and 642 kg ha−1, respectively; and increased the ACB (influx) in oat + vetch (195%) and vetch (207%). For vetch, CO2-C emission in MT was 77% greater than NT. Legume CC should be preferentially combined with NT to reduce CO2-C emissions and avoid a flush of N into the soil. The legume based-NT system showed the greatest soil C and N sequestration rates, which were significantly and positively related to soybean (Glycine max (L.) Merrill) and maize (Zea mays L.) yield. Soil C (0–90 cm depth) and N (0–100 cm depth) sequestration increments of 1 kg ha−1 corresponded to soybean yield increments of 1.2 and 7.4 kg ha−1, respectively.


2020 ◽  
Vol 12 (15) ◽  
pp. 6103
Author(s):  
Ali reza Safahani Langeroodi ◽  
Roberto Mancinelli ◽  
Emanuele Radicetti

Quinoa cultivation is well-adapted to sustainable cropping systems, even if seed yield could be severely limited due to several constraints, such as weeds. Field trials were performed in Gorgan (Iran) to quantify the effects of agro-ecological service crops (rye, CCr; winter vetch, CCw; and no cover, CC0), tillage regimes (conventional tillage, CT; and no-tillage, ZT), and herbicide rates (100% rate, H100; 75% rate, H75; and without herbicide, H0). Weed characteristics and quinoa yield were measured. Quinoa seed yield was the highest in CCw-ZT-H100. Seed yield in H100 and H75 were higher compared with H0 (2.30 vs. 1.58 t ha−1, respectively). Under conventional tillage, 46% of weed seeds were observed in the 0–10 cm soil layer and 54% in 10–20 cm soil layers, respectively, while, under no-tillage, about 63% of weed seeds were located up to 10 cm of soil. Amaranthus retroflexus L. was the most abundant species. The total weed density was the lowest in CCr-ZT-H100 and tended to be higher in CC0 (30.9 plant m−2) and under CT (29.0 plant m−2). These findings indicate that cover crops have potential for managing weeds in quinoa; however, their inclusion should be supported by chemical means to maintain high seed.


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