Assessing air-drying and rewetting pre-treatment effect on some soil enzyme activities under Mediterranean conditions (original) (raw)
Related papers
Journal of Soil Science and Plant Nutrition, 2017
Soil is a fundamental resource and it is crucial to manage its quality in order to enhance agricultural productivity and environmental quality. Soil enzymes catalyze several biochemical reactions which result in the transformation of organic matter, and the release of inorganic nutrients for plant growth and nutrient cycling. Soil enzyme activities are useful biological soil quality indicators since they are operationally practical, very sensitive, in-tegrative, easy to measure and more responsive to soil tillage and structure than other soil variables. There are several enzymes in soil, but those involved in hydrolases and the degradation of main litter components are used most often for evaluating soil quality. This paper reviews the roles of soil enzymes such as β-glucosidase, phosphatase and urease, as well as the implications of their activities for soil quality.
Air-drying pretreatment effect on soil enzymatic activity
Plant, Soil and Environment, 2017
Air-drying of soil samples is a common practice for all-purpose soil testing. However, it may cause the cessation of microbial activity changing the biochemical attributes. For this reason, field-moist samples are commonly used in the assessment of the enzyme activity in soils. This practice may, therefore, discourage the use of enzymes in soil quality evaluations. This study evaluated the effects of air-drying on cellulase, arylsulfatase and acid phosphatase activities in soil; the hypothesis was that the activities of these enzymes determined in air-dried soil samples are similar to those obtained at field-moist samples. Soil samples were collected (0–10 cm) in a long-term experiment that received two rates (10 and 20 t/ha) of sewage sludge and mineral fertilizer and was cropped with maize. Collected soil samples were split into two groups. In the first one, the enzymes were determined at field-moist samples, while in the second one, the samples were air-dried before enzymatic ana...
International Journal of Agriculture, Environment and Food Sciences
Soil is a dynamic environment that differs in both time and space and contains many living species. These living species in the soil play an important role in bringing the vitamins and hormones that promote plant growth by storing plant nutrients dissolved in water. Soil microorganisms and some other macroscopic organisms increase soil fertility so they provide vegetation enhancement especially in natural ecosystems. These living species which help to form the soil by separating rocks and minerals are influential in the formation and development processes of the soils with the parent material, topography, climate and time factors. For this reason, microorganisms have significant functions on soil fertility and quality. Microbial activity is also important in biochemical soil processes as well as it is also associated with the presence of soil enzymes (Kiss et al., 1975; Nakas et al., 1987; Martens et al., 1992; Elliott et al., 1993). Soil enzymes are related with other biological properties of soil and play a vital role in mineralization processes (Frankberger and Dick, 1983; Tate, 1987). In addition to that, enzymes such as urease, phosphatase and β-glycosidase are involved in the mineralization of organic matter in the soil and have also more effect for soil fertility (Burns, 1978). Some researcher indicated that many factors such as organic matter and agricultural practices influence the present populations of microorganisms in the soil (Coxson and Parkinson, 1987; Kowalenko et al., 1978). Thus, determination for amounts of 22
Spatial variability of phosphatase, urease, protease, organic carbon and total nitrogen in soil
Soil Biology and Biochemistry, 1991
The spatial variability of urease. phosphatase, casein-hydrolysing activities, organic C and total N was evaluated in a 5 yr old grass-legume association. Twenty four soil samples from the superficial layer (O-20 cm) were collected from a I5 x 40 m meadow. Samples were air-dried. sieved, and then stored at room temperature for I yr before being analysed. The enzymatic activities found after this time period are considered to be mainly due to enzymes protected and stabilized by their associaton or entrapment with clay minerals and humic molecules. Four ditferent procedures of statistical analysis were carried out: Analysis of Variance, statistical comparison of Coefficients of Variation, Principal Components Analysis and Proximities Analysis. With each procedure. urease activity was the most variable parameter and total N the least variable paramctcr. Phosphatase and casein-hydrolysing activities showed a similar variability. Organic C was the least variable property when a comparison among the coefficients of variation of the means was carried out, but it was the most variable property when using the analysis of variance test. These contrasting results can bc explained by the fact that organic C analytical variability is so low as to make its e&live spatial variability very important.
Effect of air-drying treatment on enzymatic activities of soils affected by anthropogenic activities
Biology and Fertility of Soils, 2003
The influence of air-drying on dehydrogenase, invertase, b-glucosidase, urease, phosphatase, arylsulphatase and phenoloxidase activities was measured in three soils affected by anthropogenic activities and in control soils sampled from neighbouring areas. The airdrying changed enzyme activity, but the behaviour was neither site-specific nor enzyme-sensitive. Canonical discriminant analysis of enzymatic activities of both moist fresh and air-dried samples was able to discriminate between altered and unaltered soils irrespective of the site. Numerical alteration indices were developed as a linear function of the seven enzyme activities and the one obtained from fresh sample data was more successful. Air-drying apparently alters in unpredictable ways enzyme activities of soils, which could lead to misinterpretation of results.
Quantitative assessment of hydrolase production and persistence in soil
Biology and Fertility of Soils, 2007
The aim of this work was to calculate indices of hydrolase production (Pr) and persistence (Pe) through simple arithmetical calculations. Changes in acid and alkaline phosphomonoesterase, phosphodiesterase, urease, protease, and β-glucosidase activities were monitored under controlled conditions in seven soils with a wide range of properties, in which microbial growth was stimulated by adding glucose and nitrogen. Glucose mineralization was monitored by CO 2-C evolution, and microbial growth was quantified by determining the soil adenosine triphosphate (ATP) content. Hydrolase Pr and Pe indices were numerically quantified by the following relationships: Pr =H /t H and Pe =(r/H)Δt, respectively, where H indicates the peak value of each measured hydrolase activity, t H is the time of the peak value, r indicates the residual activity value, and Δt is the time interval t r −t H , where t r is the time of the residual activity value. Addition of glucose and N-stimulated soil respiration increased ATP content and stimulated the production of the measured hydrolase activities in all soils; the measured variable reached a maximum value and then decreased, returning to the value of the control soil. Apart from βglucosidase activity, whose activity was not stimulated by glucose and N addition, the other measured hydrolase activities showed a trend that allowed us to calculate the Pr and Pe indices using the above-mentioned equations. Acid phosphomonoesterase and protease Pr values were significantly higher in soils under forest or set aside management; the alkaline phosphomonoesterase and phosphodiesterase Pr values were generally higher in the neutral and alkaline soils, and the urease Pr values showed no obvious relationships with soil pH or management. Concerning the persistence of enzyme activities, Pe values of the acid phosphomonoesterase activity were significantly higher in the acidic soils, and those of urease activity were higher in acidic soils and the Bordeaux neutral soil. No relationships were observed between Pe values of alkaline phosphomonoesterase, phosphodiesterase, or protease activities and soil pH or management. The different responses of hydrolases were discussed in relation to soil properties, microbial growth, and regulation at the enzyme molecular level.
Soil Enzymes – Valuable Indicators of Soil Fertility and Environmental Impacts
Bulletin UASVM Horticulture, 66(2)/2009
Soil enzymes are known since long time. A lot of older publications demonstrate the importance of exogenous soil enzymes for nutrient cycling in soils and the fertility of soils. The latter plays an extraordinary role in sustainable agriculture. Therefore indicators are needed which can be used for controlling. In our experiments with different organic amendments (green manure, straw and composts) used to improve and keep soil fertility different influences on soil enzymatic activities could be demonstrated. Fertility level was tried to characterize with - and -glucosidase, alkaline phosphatase, and urease activity. Generally could be proven that the different amendments have significant influence on the different enzymes in time and spatial distribution. Especially heavy metals in soil solution have a strong impact on soil enzyme activity. The variation of enzyme activity during time depends on the specific enzyme under consideration and the soil habitat. Activity follows also a strong gradient with soil depths. For comparative studies it is recommended to test only the upper soil layers up to a depth of 10 cm.
Applied Soil Ecology, 2015
Air-drying soil samples causes a rapid cessation of microbial activity and is a useful means of storing soil samples and standardizing experiments as moisture levels can be accurately controlled. In contrast to temperate soils, there is little information regarding the advantages and disadvantages of using fieldmoist or air-dried soil samples in the assessment of enzyme activities in tropical soils. The aim of this study was to evaluate the effects of air-drying and a two-year storage period on b-glucosidase, acid phosphatase and arylsulfatase activities in soil samples from cultivated and non-cultivated clayey Oxisols from the Cerrado region. Cultivated soil samples (0-10 cm depth) were collected from 24 treatments in three long-term experiments and analyzed to determine their enzyme activities and soil organic carbon (SOC). These treatments presented a large range of extractable Mehlich-P values and cumulative corn and soybean yields. Non-cultivated soil samples from four nearby areas with native Cerrado vegetation were also included in the study. In the laboratory, soil samples were divided into two groups. In the first group, soil samples were separated, stored at 7 C at field moisture levels and sieved through a 4 mm sieve. The analyses were performed within 1 week after sampling. In the second group, soil samples were air-dried at room temperature for two weeks, sieved through a 2 mm sieve and stored for 2 years at room temperature. Average reductions of 26%, 53% and 72%, were observed in the activities of b-glucosidase, arylsulfatase and acid phosphatase in the air-dried long-term stored samples, in both cultivated and noncultivated Cerrado clayey Oxisols. Air-drying and long-term storage hardly changed the ranking of treatments for b-glucosidase, arylsulfatase and acid phosphatase. However, a reduction in the capacity to detect changes among treatments was observed for acid phosphatase, which prevents the recommendation of air-drying prior to its analyses. As long as the effects of air-drying upon soil enzymes activities are well established, this pretreatment can be used for b-glucosidase and arylsulfatase analyses in the Cerrado clayey Oxisols. 2015 Elsevier B.V. All rights reserved.
Characterization of soil enzyme activities and physicochemical
Understanding of soil properties to maintain the soil health and crop productivity in agricultural ecosystem is vital. As a consequence, soil type and its related chemical and biological characters are being evaluated to determine the quality of soil. In this study, soil properties in tea monocropping areas were evaluated for 21 tea gardens under waterlogged condition from North Bank (NB), South Bank (SB) of the Assam and Dooars region of West Bengal (WB). A total of 260 samples from 21 tea gardens were collected for three season including pre-rainy (January-May), rainy (June-September) and post-rainy (October-December) and evaluated for different chemical and biological activities. It was found that the NB soil type was sandy to silty loam with an average age of 43 to 80 years while the SB soil type was loam to silty loam with an average age of 50 to 70 years. The soil underlying tea gardens in WB was sandy loam to heavy soil with sandy patches and the age of cultivation was above 70 years. The soils of all the tea gardens were riiildly acidic (pH values from 3.6 to 5.9). The moisture content, soil respiration and temperature of the soils in each of the gardens showed significant variation. A mixed clustering was obtained for the tea gardens with much variation during pre-and post rainy based on studied soil parameters. It was also found that there was a significant correlation during the post-rainy seasons for enzyme activities including urease, phosphatase and dehydrogenase (P less than 0.05), respectively. During pre-rainy, six principal factors influence the soil characteristics with a variance level of 49.26%. During rainy, principal factors urease and phosphatase showed negative effects over the other soil factors whereas in post-rainy pH was the significant principal factor followed by urease, moisture and temperature at the variance level of 25.97%. From the observation it could be concluded that the variations in soil physical, chemical and biological properties were observed among soils from tea gardens of Assam and WB. These variations in soil characteristics under waterlogged conditions were due to variation in the soil texture, management practice. The present finding will help in improvement of tea production by establishing correlation with soil characters.