威廉环毛蚯蚓对土壤微生物量及活性的影响

探讨威廉环毛蚯蚓(Pheretimaguillelmi)对土壤总微生物量、活性微生物量的影响。蚯蚓处理中(土壤与蚯蚓的比例为5∶1,干重∶活体重,处理时间为24h),用熏蒸提取法测定的土壤总微生物量下降,用底物诱导呼吸法测定的活性微生物量和真菌与细菌比例无显著变化;蚯蚓处理土壤促进了被微生物固持的养分的释放和土壤微生物群体年轻化,增强了微生物的代谢商和纤维素分解活性。结合对文献资料的分析,讨论了土壤微生物量的不同组分对通过蚯蚓肠道的反应。

生物膜中活性微生物对营养盐磷的吸附作用

生物膜中活性微生物对水环境中污染物质的迁移转化过程起着决定性作用。采用环境生物学中ATP生物发光检测法,研究生物膜上活性微生物量对吸附水中营养盐磷动力学过程的影响,探究微生物作用于吸附过程的机制。结果表明,自然水体培养的生物膜中活性微生物量随着培育时间的增长而增加,3天后基本保持稳定;不同生长时期的生物膜对磷的吸附能力不同,培养7天的生物膜的吸附能力最强;生物膜对磷的吸附与微生物量的变化存在明显相关关系,其吸附过程呈现四种典型阶段;高流速条件下形成较为密实的生物膜,微生物对吸附过程影响更为显著;此外,活性微生物对吸附动力学的影响还与培养水体的光照、营养状况及p H有关,碱性环境更有利于生物膜对磷的吸附。

Soil properties in reclaimed farmland by filling subsidence basin due to underground coal mining with mineral wastes in China

Reclaimed mining-induced subsidence area soils (RMSs) could restore soil quality and crop productivity in coal mining area. This study was conducted to evaluate the effects of mineral-processing wastes (fly ash vs coal gangue) as backfill substrates on soil chemical and microbial properties in mining-induced subsidence area. A general higher water holding capacity (WHC) and pH had been observed in fly ash than coal gangue reconstructed soil. Soil microbial biomass C (MBC) and N (MBN), MBC/TOC (total organic carbon) ratio (qmic) were higher under the influence of the fly ash, while contents of As, Cr, C/Nbio, the basal respiration per unit of microbial biomass (QCO2) were higher under the coal gangue reconstructed mode in 0-10, 10-20, 20-50 cm layers. The microbial basal respiration was higher in 0-10, 10-20, 0-50 cm layers, while was lower in 20-50 cm layer under fly ash than that of coal gangue reconstructed mode. The lower QCO2 of fly ash mine soil suggested the lower maintenance energy requirement of the microbial community. Moreover, the contents of metals may possibly have negative implications for soil microbial and enzyme activities in reconstructed soil.

Effects of Different Fertilization Treatments on Soil Microbial Biomass,Soil Enzyme Activities and Related Nutrients in Continuous-cropping Sugarcane Field

[Objective] This study was conducted to expound the fertility improvement effect in continuous-cropping sugarcane field and provide reference for establishment of rational sugarcane fertilization system and improvement of soil quality in continuous-cropping sugarcane field. [Method] The soil in the experimental region is latosolic red soil which was planted with sugarcane for 11 years continuously, and 8 treatments including sole application of chemical fertilizers, sole application of organ- ic fertilizer, and combined application of organic fertilizer and chemical fertilizers were designed according to different fertilization measures. The effects of different fertilization treatments on soil microbial biomass, soil enzyme activities and related fertility factors were determined. [Result} Different fertilization treatments all showed soil microbial biomass N, C and P and activities of soil acid phosphatase, catalase, sucrase and urease higher than the CK. Soil microbial biomass N increased by 5.56%-67.13%, soil microbial biomass C increased by 4.01%-20.40%, and soil mi- crobial biomass P increased by 6.39%-67.02%. The activity of acid phosphatase was improved by 12.96%-35.19%, the activity of catalase was improved by 18.24% -78.93%, the activity of sucrase was improved by 3.00%-42.00%, and the activity of urease was improved by 1.21%-23.43%. However, the soil nutrients of different fertilization treatments increased non-significantly （P〉0.05）. Soil microbial biomass N, C and P and activities of acid phosphatase, catalase and urease were in significant （P〈0.05） or very significant correlation （P〈0.01） with contents of soil rapidly available P, rapidly available K and total N. [Conclusion] The evaluation of improvement of soil fertility in continuous-cropping sugarcane field using soil microbial biomass and enzyme activities as indexes is more comprehensive and sensitive.

Bioactive Characteristics of Soil Microorganisms in Different-aged Orange (Citrus reticulate) Plantations

[Objective] The paper was to study the bioactive characteristics of soil microorganisms in different-aged orange plantations. [Method] Taking 010 cm deep soil in 3 orange plantations with different planting years in suburb of Yichang City as the test object, the variation rule of total organic carbon, total nitrogen, soil pH value, microbial biomass carbon, microbial biomass nitrogen, number of 3 main types of soil microbial flora, basal respiration, microbial entropy and metabolic entropy in differentaged orange plantations was studied. [Result] With the increase of planting years, the soil acidification of different-aged orange plantations was aggravating; total organic carbon and total nitrogen content increased first and then decreased; the total number of soil microorganism showed a downtrend, of which the number of bacteria decreased significantly, the number of actinomycetes had small changes, the number of fungi increased significantly, and the ratio of bacteria and fungi in soil （B/F） showed a decreasing trend. Soil microbial biomass carbon was fluctuated within a small range, whereas soil microbial biomass nitrogen decreased significantly; soil microbial entropy decreased significantly, and metabolic entropy showed an increasing trend. This indicated that the decrease of soil pH value affected the changes of soil microbial flora, microbial activity, microbial biomass carbon and nitrogen and soil major nutrients, and further affected the normal exertion of soil function. [Conclusion] The study explores soil nutrient characteristics and changes of microbial flora in test area, which will provide scientific basis for further study on orchard soil and orchard management.

Effects of Different Fertilization Treatments on Biological Activity of Reclaimed Soil

As per randomized block design, the research had different fertilizer treatments, and the organic matter, respiration, enzyme activity and microbial carbon and nitrogen in reclaimed soil were studied. Fertilization schemes were as follows： The treatment without fertilizers（CK）, the treatment with chemical fertilizers（C）, the treatment with chemical fertilizers and bacterial fertilizer（CB）, the treatment with organic fertilizer and chemical fertilizers（CM）, and the treatment with chemical fertilizers, organic fertilizer and bacterial fertilizer（CMB）. The results showed： Four fertilization treatments could improve the content of soil organic matter. CMB, CM and CB could significantly improve the soil respiration. Organic fertilizer and fertilizer could significantly improve soil enzyme activity, In different growth stages the CMB treatment had highest urease and phosphatase.The most significant in the treatment content of sucrose was CM. Organic fertilizer and microbial fertilizer can significantly improve the microbial carbon and nitrogen in soil. For the microbial biomass carbon, the CMB treatment increased by 11%-34% than CB treatment, and 35%-63% than C treatment. In terms of microbial nitrogen CMB, CM respectively increased by 31%-51% than CB treatment, and 52%-100% compared with C. In the process of land reclamation, we should combine the organic fertilizer, microbial fertilizer and inorganic fertilizer. Only in this way can soil biological activity be accelerated, soil microbial environment improved, and the ripening increased soil nutrient and soil cultivation be enhanced.

Impact of Vanadium on Enzyme Activity and Microbial Biomass in Soils

[Objective] This study aimed to investigate the impact of vanadium at dif- ferent concentration on enzyme activity and microbial biomass in soils. [Method] Us- ing pot experiments in the growth cabinet, we would like to investigate the changes of the soil enzyme activity and microbial biomass at different growing stages of rape （Brassica juncea L.） at different soil vanadium concentrations （soil background value was 147 mg/kg, spiked with 0, 50, 100, 150, 250 and 500 mg/kg of exogenous vanadium）. [Result] Among all enzymes examined, polyphenol oxidase was most sensitive to soil vanadium. Addition of 50 mg/kg vanadium decreased its activity up to 56% of the control probably due to the vanadium toxicity. In comparison, the ac- tivities of sucrase, urease and catalase was less affected by soil vanadium. Surpris- ingly, the activity of sucrase, urease and catalase at the rape seedling stage differed significantly from at the maturity stage, highlighting the potential impact of plant growth on the vanadium-soil enzyme interaction. Different soil vanadium concentra- tions led to increases of microbial biomass to different extents. However, the corre- lation between soil microbial biomass carbon and phosphorus with vanadium con- centrations was insignificant. This revealed that the presence of additional factors （eg. plant） affected soil microbial biomass carbon and phosphorus aside from soil vanadium. [Conclusion] Polyphenol oxidase may be considered as an indicator of soil vanadium contamination. Due to the highly complicated interaction between vanadium and soil biological activities during plant growth, more investigations are required to reveal the mechanisms beyond our findings here.

Investigations into the corrosive environments contributing to premature failure of Australian coal mine rock bolts

University of New South Wales(UNSW Australia) had been involved in the study of premature failure of rock bolts in Australia coal mines from the initial identification of the problem in 1999. Rock bolt steel changes over the last decade appear to have not reduced the incidence of failures. A broadened UNSW research project funded by the Australian Research Council(ARC) and Industry has targeted finding the environmental causes through extensive field and laboratory experiments. This paper describes the field studies conducted in underground coal mines,in particular attempts to measure the contribution to corrosion from groundwater,mineralogy and microbial activity. Various underground survey techniques were used to determine the extent of broken bolts,with the presence of both stress corrosion cracking(SCC) and localized deep pitting making no single technique suitable on their own.Groundwater found dripping from bolts across various coalfields in Australia were found to be not aggressive and known groundwater corrosivity classification systems did not correlate to where broken bolts were found. In-hole coupon bolts placed in roof strata containing claystone bands confirmed the clay as being a major contributor to corrosion. Microbes capable of contributing to steel corrosion were found to be present in groundwater,and culturing of the microbes taken from in-situ coupon bolts proved that the bacteria was present on the bolt surface. An ‘in-hole bolt corrosion coupon' development by the project may have multiple benefits of (1) helping quantify newly developed corrosivity classification systems,(2) providing an in-situ ground support corrosion monitoring tool,and (3) for testing possible corrosion protection solutions.

Soil organic carbon pool along different altitudinal level in the Sygera Mountains, Tibetan Plateau

Labile organic carbon（LOC） is one of the most important indicators of soil organic matter quality and dynamics elevation and plays important function in the Tibetan Plateau climate. However, it is unknown what the sources and causes of LOC contamination are. In this study, soil organic carbon（SOC）, total nitrogen（TN）, microbial biomass carbon（MBC）, microbial biomass nitrogen（MBN） and LOC were analyzed based on different soil horizons and elevations using turnover time in an experimental site（3700 m to 4300 m area） in Sygera. SOC and LOC in higher-elevation vegetation types were higher than that of in lower-elevation vegetation types. Our results presented that the soil microbial biomass carbon（SMBC） and soil microbial biomass nitrogen（SMBN）were positively correlated with SOC. The content of easily oxidized carbon（EOC）, particulate organic carbon（POC） and light fraction organic carbon（LFOC） decreased with depth increasing and the content were the lowest in the 60 cm to 100 cm depth.The total SOC, ROC and POC contents decreased with increasing soil horizons. The SOC, TN, MBC and MBN contents increased with increasing altitude in the Sygera Mountains. The MBC and MBN contents weredifferent with the changes of SOC（p＆lt;0.05）,meanwhile, both LFOC and POC were related to total SOC（p＆lt;0.05）. The physical and chemical properties of soil, including temperature, humidity, and altitude,were involved in the regulation of SOC, TN, MBC,MBN and LFOC contents in the Sygera Mountains,Tibetan Plateau.

Quality Characteristics and Microbiology Status in Kundi, an Intermediate Moisture Meat （IMM） Product

Meat and meat products are extremely perishable, so special care and handling must be exercised during slaughtering operation. Moreover, due to its high nutritive value, deterioration set in immediately after slaughtered, therefore it is necessary to preserved meat, using simple techniques. One of such method of preservation is drying method to produced Intermediate Moisture Meat （IMM）. The quality attributes and microbiological status of Kundi, a West African dried meat product （IMM） were studied over three months of storage period by comparing commercial products and laboratory Kundi products. Chemical and minerals composition and microbiological counts were reported. Moisture and water activity results indicated that the experimental Kundi was sufficiently dried to minimize microbial growth. Fat oxidation levels measured by free fatty acids （FFA, %） on extracted fats were unacceptably high for the commercial Kundi （2.64%）, which may be a reflection of the oil used in spraying the products. Processing of Kundi, appears to have relative higher amounts of minerals than fresh meat but their relative solubility were lower. Aflatoxin levels far exceeded established safe limits for commercial samples while laboratory samples fell under the safe limits, resulting from the mould growth in each product, with laboratory samples having lower growth than commercial samples.

Soil Enzyme Activities on Eroded Slopes in the Sichuan Basin, China

Determining how soil erosion affects enzyme activity may enhance our understanding of soil degradation on eroded agricultural landscapes. This study assessed the changes in enzyme activity with slope position and erosion type by selecting water and tillage erosion-dominated slopes and performing analyses using the 1376s technique. The 137Cs data revealed that soil loss occurred in the upper section of the two eroded slope types, while soil accumulation occurred in the lower section. The invertase activity increased downslope and exhibited a pattern similar to the 137Cs data. The spatial patterns of urease and alkaline phosphatase activities were similar to the 137Cs inventories on the water and tillage erosion-dominated slopes, respectively. On both the eroded slope types, the invertase activity and soil organic carbon content were correlated, but no correlation was observed between the alkaline phosphatase activity and total phosphorus content. Nevertheless, the urease activity was correlated with the total nitrogen content only on the water erosion-dominated slopes. The enzyme activity-to-microbial biomass carbon ratios indicated high activities of invertase and urease but low activity of phosphatase on the water erosion-dominated slopes compared with the tillage erosion-dominated slopes. Both the invertase activity and the invertase activity-to-microbial biomass carbon ratio varied with the slope position. Changes in the urease activity-to-microbial biomass carbon ratio were significantly affected by the erosion type. These suggested that the dynamics of the invertase activity were linked to soil redistribution on the two eroded slope types, whereas the dynamics of the urease and alkaline phosphatase activities were associated with soil redistribution only on the water or tillage erosion-dominated slopes, respectively. The erosion type had an obvious effect on the activities of invertase, urease and alkaline phosphatase. Soil redistribution might influence the involvement of urease in the N cycle and alkaline phosphatase in the P cycle. Thus, enzyme activity-to-microbial biomass ratios may be used to better evaluate microbiological activity in eroded soils.

Changes in Soil Organic Carbon Dynamics in a Native C4 Plant-Dominated Tidal Marsh Following Spartina alterniflora Invasion

Invasion of an exotic C4 plant Spartina alterniflora has been shown to increase soil organic carbon （SOC） concentrations in native C3 plant-dominated coastal wetlands of China. However, little is known about the effects of S. alterniflora invasion on SOC concentrations and fractions in tidal marshes dominated by native C4 plants. In this study, a field experiment was conducted in a tidal marsh dominated by the native C4 plant Cyperus malaccensis in the Minjiang River estuary, China. Concentrations of SOC and liable SOC fractions, dissolved organic carbon （DOG）, microbial biomass carbon （MBC）, and easily oxidizable carbon （EOC）, were measured in the top 50-cm soils of the C. malaccensis community, as well as those of three S. alterniflova communities with an invasion duration of 0-4 years （SA-4）, 4-8 years （SA-8）, and 8-12 years （SA-12）, respectively. Results showed that both SOC stocks in the 50-cm soils and mean SOC concentrations in the surface soils （0-10 cm） of the C. malaccensis community increased with the duration of S. alterniflora invasion, whereas SOC concentrations in the 10-50-cm soils decreased slightly during the initial period of S. alterniflora invasion, before increasing again. The pattern of changes in labile SOC fractions （DOC, MBC, and EOC） with invasion duration was generally similar to that of SOC, while the ratios of labile SOC fractions to total SOC （DOC：SOC, MBC：SOC, and EOC：SOC） decreased significantly with the duration of S. alterniflora invasion. The findings of this study suggest that invasion of the exotic C4 plant S. alternifora into a marsh dominated by the native C4 plant C. malaecensis would enhance SOC sequestration owing to the greater amount of biomass and lower proportion of labile SOC fractions present in the S. alterniflora communities.

Effects of Maize Residue Quality and Soil Water Content on Soil Labile Organic Carbon Fractions and Microbial Properties

Investigating the effects of residue chemical composition on soil labile organic carbon （LOC） will improve our understanding of soil carbon sequestration. The effects of maize residue chemical composition and soil water content on soil LOC fractions and microbial properties were investigated in a laboratory incubation experiment. Maize shoot and root residues were incorporated into soil at 40% and 70% field capacity. The soils were incubated at 20 ℃ for 150 d and destructive sampling was conducted after 15, 75, and 150 d. Respiration, dissolved organic carbon （DOC）, hot-water extractable organic carbon （HEOC）, and microbial biomass carbon （MBC） were recorded, along with cellulase and β-glucosidase activities and community-level physiological profiles. The results showed that the cumulative respiration was lower in root-amended soils than in shoot-amended soils, indicating that root amendment may be beneficial to C retention in soil. No significant differences in the contents of DOG, HEOC and MBC, enzyme activities, and microbial functional diversity were observed between shoot- and root-amended soils. The high soil water content treatment significantly increased the cumulative respiration, DOC and HEOC contents, and enzyme activities compared to the low soil water content treatment. However, the soil water content treatments had little influence on the MBC content and microbial functional diversity. There were significantly positive correlations between LOC fractions and soil microbial properties. These results indicated that the chemical composition of maize residues had little influence on the DOC, HEOC, and MBC contents, enzyme activities, and microbial functional diversity, while soil water content could significantly influence DOC and HEOC contents and enzyme activities.

Soil Microbial and Enzymatic Activities Across a Chronosequence of Chinese Pine Plantation Development on the Loess Plateau of China

Successional and seasonal effects on soil microbial and enzymatic properties were studied in Chinese pine （Pinus tabulaeformis） plantations in an age sequence of 3-, 7-, 13-, 21- and 28-year-old in northern Ziwuling region in the middle of Loess Plateau, China. The results indicated that plantation age and season affected soil microbial and enzymatic parameters significantly. Soil organic C, total N, microbial biomass C, microbial quotient, basal respiration, dehydrogenase, N-α-benzoyl-L-argininamide （BAA）-protease, urease and β-glucosidase increased quickly and tended to be highest at PF21 （21-year plantation）, thereafter they remained nearly at a constant level, whereas the metabolic quotient （qCO2） showed an initial increase and then decreased gradually. Measures of these soil properties showed significant seasonal fluctuations except for organic C and total N, which were found to be relatively stable throughout the study period, and the seasonal distributions were autumn 〉 spring 〉 summer 〉 winter for microbial biomass C, microbial quotient, dehydrogenase, and β-glucosidase; autumn 〉 summer 〉 spring 〉 winter for BAA-protease and urease; and summer 〉 autumn 〉 spring 〉 winter for basal respiration and qCO2. Significant season x age interaction was observed for biomass C, basal respiration, dehydrogenase and BAA-protease.

Biochar-Soil Interactions in Four Agricultural Soils

Soils in south-western Australia are highly weathered and deficient in nutrients for agricultural production. Addition of biochar has been suggested as a mean of improving soil C storage, texture and nutrient retention of these soils. Clay amendment in sandy soils in this region is a management practice used to improve soil conditions, including water repellence. In this study a woody biochar(Simcoa biochar) was characterised using scanning electron microscopy before, and four weeks after, it was incorporated into each of four soils differing in clay content and organic matter. Scanning electron microscopy of Simcoa biochar after incubation in soil showed different degrees of attachment of soil particles to the biochar surfaces after 28 d. In addition, the effects of three biochars, Simcoa biochar, activated biochar and Wundowie biochar, on soil microbial biomass C and soil respiration were investigated in a short-term incubation experiment. It was hypothesised that all three biochars would have greater potential to increase soil microbial activity in the soil that had higher organic matter and clay. After 28-d incubation in soil, all three biochars had led to a higher microbial biomass C in the clayey soil, but prior to this time, less marked differences were observed in microbial biomass C among the four soils following biochar application.

Effects of Earthworms and Ryegrass on the Removal of Fluoranthene from Soil

Earthworms can promote the bioremediation of contaminated soils through enhancing plant growth and microorganism development. The individual and combined effects of earthworms and ryegrass （Lolium multifloram Lain.） on the removM of fiuoranthene from a sandy-loam alluvial soil were investigated in a 70-d microcosm experiment. The experiment was set up in a complete factorial design with treatments in four replicates： without earthworms or ryegrass （control, CK）, with earthworms only （E）, with ryegrass only （P）, and with both earthworms and ryegrass （EP）. The residual fluoranthene, microbial biomass C, and polyphenol oxidase activity in the soil changed significantly （P 〈 0.01） with time. In general, the residual concentration of fluoranthene in the soil decreased sharply from 71.8-88.7 to 31.7-37.4 mg kg-1 in 14 d, and then decreased gradually to 19.7-30.5 mg kg-1 on the 70th d. The flu- oranthene concentration left in the soil was the least with both earthworms and ryegrass, compared to the other treatments at the end of the experiment. Half-life times of fluoranthene in the E, P, and EP treatments were 17.8%-36.3% smaller than that of CK. More fluoranthene was absorbed by earthworms than ryegrass. However, the total amounts of fluoranthene accumulated in both the ryegrass and earthworms were small, only accounting for 0.01%-1.20% of the lost fluoranthene. Therefore, we assumed that microbial degradation would play a dominant functional role in fluoranthene removal from soil. We found that earthworms significantly increased microbial biomass C and polyphenol oxidase activity （P 〈 0.01） in the presence of ryegrass at the end of the experiment. Furthermore, microbial biomass C and polyphenol oxidase activity were significantly （P 〈 0.05） and negatively related to the residual fluoranthene concentration. This implied that earthworms might promote the removal of fluoranthene from soil via stimulating microbial biomass C and polyphenol oxidase activity.

Soil calcium content as the driving factor for vegetative structure and soil microbial function diverging across a fire chronosequence of the boreal forests in northeast China

The role of biophysical variables in constructing community structure changes with the time since fire.The major objective of this study is to verify the transition stage and its underlying variables for the postfire forest and soil microbial function in the boreal forested area of China.A 50-year fire chronosequence was presented,and biomass of forbs,shrubs and woody plants was separately weighted to assess their contribution to the whole community with the year since fire(YSF).Simultaneously,soil biophysical properties were measured for stands in different time periods after fire.Soil microbial functions,i.e.growth efficiency(GE)and carbon use efficiency(CUE),were calculated based on ecoenzymatic and soil nutrient stoichiometry.In terms of vegetative structure,forbs’proportion decreased from 75%to 1.5%,but the proportion of woody plants increased from 0.04%to 70%across this fire chronosequence.GE and CUE of soil microorganisms averaged 0.242 and 0.236 and were significantly higher in 9,15 and 31 YSF than in 2 and 3 YSF.Soil metal content was significantly increased at the late stage of this fire chronosequence,and soil calcium content showed a positive correlation with woody plant biomass and a negative correlation with soil microbial function.Overall,the present work highlights that the time period of 15 and 31 YSF is a hallmark stage for aboveground vegetative structure and soil microbial function to change in different trends and that the calcium content may partly account for these two divergent trajectories.

Influences of Catch Crop and Its Incorporation Time on Soil Carbon and Carbon-Related Enzymes

Catch crops that are cultivated for green manure play an important role in improving soil properties. A 3-year field experi- ment was conducted to investigate the effect of catch crop （pea, Pisum sativum L.） management, i.e., incorporation of catch crop in October/November （autumn） and March （spring）, and without catch crop （control）, on soil organic carbon （SOC）, microbial biomass carbon （MBC） and the activities of carbon （C）-cycle enzymes, including cellulase （Cel）, β-glucosidase （Glu） and invertase （Inv）. Additionally, soil total nitrogen （TN） and pHKcl were investigated. The catch crop was cultivated from August to October each year during 2008-2010. Soil samples were collected from the field of spring barley （Hordeum vulgate L.） that had been grown after the catch crop. Soil samples for microbial activity determination were taken in March, May, June and August in 2009, 2010 and 2011, while SOC and TN contents as well as pHKc1 were determined in March and August. The chemical properties studied did not show significant changes as influenced by the experimental factors. The use of catch crop significantly increased the MBC content and the activities of C-cycle enzymes compared to the control. When the catch crop was incorporated in spring, a significantly higher MBC content was noted in March and May compared to autumn incorporation. Moreover, the spring incorporation of the catch crop significantly increased the Glu activity （except March）, while the activities of Cel and Inv as well as the rate of soil basal respiration were usually unaffected by the time of catch crop incorporation. Greater microbial biomass and higher enzyme activities in the catch crop-treated soil, compared to the control, indicated that the application of the catch crop as a green manure could be recommended as a promising technique to increase the biological activity of the soil. Since there was no significant effect or no consistent results were obtained related to the time of catch crop incorporation, both spring and autumn applications can be recommended as a management tool to improve the status of soil properties during the growth of a subsequent crop.