NF Soil Research Articles

Vegetation restoration of abandoned cropland improves soil ecosystem multifunctionality through alleviating nitrogen-limitation in the China Danxia.

The microbial requirement for nutrient resources can be estimated by soil extracellular enzyme stoichiometry (EES) and their stoichiometries. Implementing the Grain for Green Program has significantly impacted land use and soil nutrient management in the China Danxia. However, drivers of soil microbial nutrient limitation changes in abandoned cropland (AC) remained unclear after vegetation restoration. Here, according to vector analysis, we evaluated microbial nutrient limitation by studying soil EES across vegetation restoration types (naturally restored secondary forests (NF) and artificially planted forests (AF)) with AC as a control. Results showed both NF and AF soils averaged higher C- and P- acquiring enzyme, indicating rapid C and P turnover rates after vegetation restoration. However, vegetation restoration resulted in higher C requirement for microorganisms with higher enzyme C:N and vector length. In addition, microorganisms shifted from N- (< 45°) to P-limited (> 45°) conditions with enzyme N:P less than 1 after vegetation restoration, and NF exacerbated microbial P limitation compared to AF. Decreased N limitation following vegetation restoration could be contributed to improving soil ecosystem multifunctionality. The greater variation of EES was explained by the interaction of pH, soil nutrient, and microbial biomass than by any one of these factors alone, suggesting that both abiotic and biotic factors regulate microbial nutrient limitation and microbial process. Overall, our results revealed vegetation restoration could alleviate N limitation in the China Danxia, and thus enhance soil ecosystem by regulating lower microbial N limitation, which provide insight into nutrient management strategies under ecological restoration of degraded areas.

Past sewage sludge application did not alter soil chemical properties or abundance of most abundant bacterial families in an agroforestry system

Forest management practices impact the amount of organic matter reaching the soil, but also the soil properties and/or vegetation composition that influence soil microbiome structure and composition.After 15 years of the last application of sewage sludge (SS) alone or in combination with CaCO3 to soils of a silvopastoral system with Pinus radiata D. Don, still some residual effects were observed in the soil chemical parameters (such as pH, exchangeable Na, Ca, or K) but bigger changes on soil bacterial families were detected. However, no significant effect of the fertilisation was found in the total amount of soil organic matter or its mid-infrared spectral signature. Acidobacteriaceae, Sinobacteraceae, Bradyrhizobiaceae, Burkholderiaceae and Pseudonocardiaceae were the most abundant identified families in all treatments and light changes in their abundances were detected in the different soil treatments. However, when looking at the bacterial diversity (number of families) a strong decrease in the number of specific bacteria linked to the NF soils (Non fertilised) was observed in the SS treated soils (and this decrease was even more pronounced when SS was combined with CaCO3). Soil pH and exchangeable Al were found the main factors shaping the structure of bacterial families in the studied soils, while other factors such as total soil P, exchangeable Na, exchangeable K showed the lowest correlation with bacterial abundances. Most of correlations between soil pH and families' abundances were negative while in the case of exchangeable Al, both negative and positive correlations were observed equally. The Thermomonosporaceae, Acidimicrobiaceae and Coriobacteriaceae families showed the highest number of significant correlations with soil chemical parameters (pH, total N, organic C, exchangeable K and Al and CEC).

Kinetic Indices of Enzyme Activity used as Sensitive Biomarkers to Monitor Mine Spoil Genesis in Chronosequence Coal Mine Overburden Spoil

Mine spoil genesis mostly focuses on careful consideration of enzyme activities and kinetics parameters toelucidate microbial mediated biotransformation and nutrient cycling including their link with the variationin physicochemical properties, microbial community dynamics and landscape ecology as the functionaldeterminants of ecosystem function. The relative distribution of microbial populations exhibited progressiveincrease in different age series coal mine overburden spoil over time. The kinetic parameters of amylase,invertase, protease, urease, phosphates and dehydrogenase activities were determined to assess the metabolicresponse in different age series coal mine spoil. Gradual increase in Vmax and decline in Km of enzymeactivities representing the quality and affinity of enzymes correlated well with the shift in microbialcommunity composition over time. Besides, the shift in catalytic efficiency (Vmax/Km) has greatersignificance as early and sensitive indicators of the changes in soil properties influencing microbialcommunity dynamics across the sites. The enzyme activity and kinetic parameters correlated well the changesin physicochemical properties over time across the sites. PCA and RDA analysis can able to discriminatesix different age series coal mine overburden spoil and nearby NF soil into independent clusters based onthe variability in physicochemical properties, microbial community structure, enzyme activities and kineticparameters. The study suggested that the kinetic indices of enzyme activities can be used as reliable ecologicalbiomarkers to monitor the progress of mine spoil genesis.

Sulfur speciation in a tropical soil amended with lime and phosphogypsum under long-term no-tillage system

Sulfur (S) is present mainly in organic forms in the most superficial layers of well-drained soils, despite sulfate (SO42−) being the main S-species absorbed by plants. Coupled broadcast application of lime and phosphogypsum (PG) is widely deployed as an agricultural practice to improve soil chemical properties and increase crop yields in highly weathered tropical soil areas under no-tillage system (NTS). However, the effects of large-scale application of these soil amendments to S-species distribution in soil in NTS are largely unknown. We combined S wet-chemical analysis with Synchrotron-based X-ray Absorption Near-Edge Structure Spectroscopy (XANES) to evaluate the effects of lime and PG application to S-species distribution along the soil profile (up to 150 cm). Soil samples were collected from a field-scale experiment under NTS for over 15 years. Soil was amended with lime and PG, either individually or in combination, four times during the experiment. Soil sampling was conducted 16 months after the last amendments’ application, and treatments (lime, PG and lime + PG) were compared to a control (under NTS without amendments’ application) and with soil samples from a native forest (reference for an undisturbed site). Broadcast PG application increased the contents of Ca-phosphate extractable S and pseudo-total S (microwave assisted acid digestion) contents in the deeper layers. Two peaks representing reduced and oxidized S species were detected in S K-edge XANES spectra of all treatments and NF soil. The oxidized S peak gets sharper with increase in depth, as reduced S peak intensity decreases, and fingerprint analysis suggested a greater contribution of reduced organic S species in the most superficial soil layer followed by an increase in highly oxidized S species as depth increased. Linear combination fitting analysis confirmed a greater contribution of highly oxidized S species to the total S-species as depth increased, especially in soil samples that received PG application.

Linking rhizosphere soil biochemical and microbial community characteristics across different land use systems in mountainous region in Northeast India

In Northeast India, widely practiced shifting cultivation practice created various land uses associated with altered soil biochemical and microbial attributes. The present study aimed to analyze soil biochemical and microbial characteristics in rhizosphere using Illumina paired-end sequencing in five dominant land uses (Oil Palm Plantation, OPP; Bamboo Forest, BF; Rubber Plantation, RP; Fallow Land, FL and Natural Forest, NF) of Mizoram, Northeast India. The soils of different land uses were strongly acidic (pH ranged from 4.4–5.3) in nature reflecting the dominance of acidophilic soil microbes (e.g. Acidobacteria, Proteobacteria and Verrucomicrobia) and majority of unassigned bacteria accounting >50% of all sequences. NF soil showed high organic carbon and total nitrogen (TN), however, levels of available phosphorous (Pavail), microbial biomass carbon, ammonium and nitrate nitrogen, and rates of N-mineralization (N-min) were considerably high in BF. Basal soil respiration significantly (p < .05) varied across land uses with maximum in RP and minimum in BF. Species diversity estimator showed highest bacterial diversity in BF (pH 5.3) and lowest in FL (pH 4.4). Acidobacteria were dominant in NF which declined with land use changes due to increase in soil pH. Soil pH was the strongest predictor variable explaining 96% variability of microbial diversity (R2-predicted, 78%), however, it explained 99% variability (R2-predicted, 99%) in combination with Pavail and TN. High N-min rate in BF soil was corresponded with maximum abundance of Nitrospirae. The study indicated that the changing land use patterns in this region are intertwined with changing soil biochemical and bacterial community structure.

Effect of long-term fertilization on decomposition of crop residues and their incorporation into microbial communities of 6-year stored soils

To investigate the effects of long-term fertilization on microbial decomposition of residues and priming effect (PE), 13C-labeled maize (Zea mays L.) residues were supplied to arable soils with a 20-year application of compost (COM), mineral NPK fertilizer (NPK), or without any treatments, the no-fertilizer control (NF). The soils that had been stored for 6 years were used in the present incubation experiment. The release of CO2–C and the microbial incorporation of residue-derived C determined by phospholipid fatty acids (PLFAs) analysis were monitored over a 90-day incubation period. Residue additions significantly increased cumulative CO2–C emission and induced positive PE. Cumulative residue-derived CO2-C emission and PE mainly occurred within the first 15 days. The COM soil had significantly higher cumulative residue-derived CO2–C emission but lower PE than the NF and NPK soils. Residue additions significantly increased microbial abundance and changed the composition of main microbial groups. The COM soil showed a significantly lower relative fungal abundance (mol%) but a higher relative actinomycetes abundance than the NF and NPK soils. The incorporation of residue-derived C within fungi was the highest among all the main microbial groups and decreased from 15 to 45 days, while the incorporation of residue-derived C within actinomycetes increased with time in three soils. The incorporation of residue-derived C within fungi was the highest in the COM soil over the course of incubation. The long-term compost input promoted fungal use of residue C and stimulated residue decomposition.

Effect of the nematophagous fungus Pochonia chlamydosporia on soil content of ascarid eggs and infection levels in exposed hens

BackgroundThe nematophagous fungus Pochonia chlamydosporia can degrade ascarid (e.g. Ascaridia galli) eggs in agar and soil in vitro. However, it has not been investigated how this translates to reduced infection levels in naturally exposed chickens. We thus tested the infectivity of soil artificially contaminated with A. galli (and a few Heterakis gallinarum) eggs and treated with P. chlamydosporia. Sterilised and non-sterilised soils were used to examine any influence of natural soil biota.MethodsUnembryonated eggs were mixed with sterilised (S)/non-sterilised (N) soil, either treated with the fungus (F) or left as untreated controls (C) and incubated (22 °C, 35 days) to allow eggs to embryonate and fungus to grow. Egg number in soil was estimated on days 0 and 35 post-incubation. Hens were exposed to the soil (SC/SF/NC/NF) four times over 12 days by mixing soil into the feed. On day 42 post-first-exposure (p.f.e.), the hens were euthanized and parasites were recovered. Serum A. galli IgY level and ascarid eggs per gram of faeces (EPG) were examined on days -1 and 36 (IgY) or 40 p.f.e. (EPG).ResultsEgg recovery in SF soil was substantially lower than in SC soil, but recovery was not significantly different between NF and NC soils. SF hens had a mean worm count of 76 whereas the other groups had means of 355–453. Early mature/mature A. galli were recovered from SF hens whereas hens in the other groups harboured mainly immature A. galli. Heterakis gallinarum counts were low overall, especially in SF. The SF post-exposure IgY response was significantly lower while EPG was significantly higher compared to the other groups.ConclusionsPochonia chlamydosporia was very effective in reducing ascarid egg numbers in sterilised soil and thus worm burdens in the exposed hens. However, reduced exposure of hens shifted A. galli populations toward a higher proportion of mature worms and resulted in a higher faecal egg excretion within the study period. This highlights a fundamental problem in ascarid control: if not all eggs in the farm environment are inactivated, the resulting low level infections may result in higher contamination levels with associated negative long-term consequences.

Chemical and microbiological properties in soil cultivated with sugarcane (Saccharum officinarum)

The aim of this study was to evaluate the response of chemical parameters and microbiological processes related to the nitrogen (N) cycling in an area cultivated with sugarcane (SC), as compared to the native forest area (NF), considered as the reference. The pH value, the total C (C tot ), N (N tot ) contents, the P, K, Ca, Mg, Zn, Mn, B and Cu contents, the labile carbon (LC) content, cation exchange capacity (CEC), microbial biomass N (N mic ), potentially mineralizable nitrogen (PMN) and the urease activity (UA) were determined in soil samples taken at depths of 0-10 and 10-20 cm. Most of the chemical properties were higher in the NF soil at both depths, except for C tot , N tot and the total K content, which did not present significant differences between the areas at the deeper level. All microbiological processes were higher in the NF soil and showed positive correlations with the total Cu and B contents, demonstrating the importance of these nutrients in the biological N cycling. The higher values obtained for almost all parameters in the NF soil attest to the need for constant monitoring of areas cultivated with sugarcane in order to avoid the adverse effects of soil degradation. The results obtained between the areas, in relation to N cycling processes also demonstrated the suitability of using them as reliable indicators of soil quality.

Soil gross nitrogen transformations along a secondary succession transect in the north subtropical forest ecosystem of southwest China

Soil nitrogen (N) transformations in forest soils play a vital role in plant N availability. However, the effect on soil N dynamics of forest succession remains largely unknown. A 15N tracing study was conducted in situ to investigate gross N transformation rates along a secondary succession transect (grassland GL, coniferous forest CF, coniferous-broad-leaved mixed forest CBF, broad-leaved forest BF, natural broad-leaved forest NF) under a north subtropical monsoon climate. Gross N mineralization and NH4+ immobilization rates were significantly higher in the BF soil than in the NF, CBF, GL and CF soils, although no significant differences were found among the latter four soils. Gross NO3− immobilization rates in the GL and CF soils were negligible, and were significantly lower than those in the three late succession stage soils. In all soils, NO3− was produced almost exclusively by heterotrophic nitrification. The ratio of the gross NO3− immobilization rate to the gross nitrification rate was significantly lower in the GL and CF soils than in the other three soils, indicating a higher NO3− retention capacity in the three late successional stage soils. The combination of higher gross N mineralization, NH4+ and NO3− immobilization turnover and higher NO3− retention promotes a faster N turnover, resulting in greater N availability and N retention capacity in the late successional stages. Such results also suggested that during succession, internal N cycles adapt and develop mechanisms (i.e. increasing soil organic C and N concentration) in response to soil–plant interactions that enhance the soil N supply and N retention.

Conversion of a natural evergreen broadleaved forest into coniferous plantations in a subtropical area: effects on composition of soil microbial communities and soil respiration

In this study, we examined how the conversion of native broadleaved forests into plantations of more productive forest species for timber use affects soil microbial community composition at 0–10-cm depth and soil respiration by comparing two 36-year-old plantation forests of Chinese fir (Cunninghamia lanceolata, CF) and Pinus massoniana (PM) with an adjacent relict natural forest of Castanopsis carlesii (NF, ~200 years old) in Sanming, Fujian, China. The soil microbial community composition was determined by phospholipid fatty acid (PLFA) analysis. The monthly in situ soil respiration rate was measured from October 2010 to September 2012. Results showed that the abundance of Gram-negative bacterial PLFAs, actinomycetal PLFAs, and total PLFAs did not vary significantly with forest conversion. The CF soil was characterized by higher abundance of fungal PLFA and lower abundance of Gram-positive bacterial PLFA compared with NF and PM soils. Redundancy analysis (RDA) indicated that the significant change in the composition of soil microbial community was mainly due to fine root biomass and soil pH. Annual soil respiration rate averaged 161.7 mg C m−2 h−1 in NF, 95.1 mg C m−2 h−1 in CF, and 103.2 mg C m−2 h−1 in PM. The NF showed significantly higher mean annual soil CO2 flux (1421 g C m−2 year−1) than CF (837 g C m−2 year−1) and PM (907 g C m−2 year−1). After forest conversion, the apparent temperature sensitivity of soil respiration (Q 10) increased from 1.75 in NF to 2.04 and 1.98 in CF and PM, respectively. The mean annual soil respiration was significantly correlated with soil organic C (SOC) content and abundances of microbial PLFAs except for abundance of fungal PLFA, but not significantly correlated with fine root biomass (<2 mm in diameter) across the different forest soils. The latter behavior may be due to the higher fine root biomass in the CF than in the NF and PM. Our results suggest that studies incorporating the microbial community composition with soil respiration may enhance our understanding of the mechanisms of soil C dynamics.

Land use effects on soil organic carbon, microbial biomass and microbial activity in Changbai Mountains of Northeast China

Land use changes are known to alter soil organic carbon (SOC) and microbial properties, however, information about how conversion of natural forest to agricultural land use as well as plantations affects SOC and microbial properties in the Changbai Mountains of Northeast China is meager. Soil carbon content, microbial biomass carbon (MBC), basal respiration and soil carbon mineralization were studied in five selected types of land use: natural old-growth broad-leaved Korean pine mixed forest (NF); spruce plantation (SP) established following clear-cutting of NF; cropland (CL); ginseng farmland (GF) previously under NF; and a five-year Mongolian oak young forest (YF) reforested on an abandoned GF, in the Changbai Mountains of Northeast China in 2011. Results showed that SOC content was significantly lower in SP, CL, GF, and YF than in NF. MBC ranged from 304.4 mg/kg in CL to 1350.3 mg/kg in NF, which was significantly higher in the soil of NF than any soil of the other four land use types. The SOC and MBC contents were higher in SP soil than in CL, GF, and YF soils, yielding a significant difference between SP and CL. The value of basal respiration was also higher in NF than in SP, CL, GF, and YF. Simultaneously, higher values of the metabolic quotient were detected in CL, GF, and YF soils, indicating low substrate utilization of the soil microbial community compared with that in NF and SP soil. The values of cumulative mineralized carbon and potentially mineralized carbon (C 0) in NF were significantly higher than those in CL and GF, while no significant difference was observed between NF and SP. In addition, YF had higher values of C 0 and C mineralization rate compared with GF. The results indicate that conversion from NF into agricultural land (CL and GF) uses and plantation may lead to a reduction in soil nutrients (SOC and MBC) and substrate utilization efficiency of the microbial community. By contrast, soils below SP were more conducive to the preservation of soil organic matter, which was reflected in the comparison of microbial indicators among CL, GF, and YF land uses. This study can provide data for evaluating soils nutrients under different land use types, and serve as references for the rational land use of natural forest in the study area.

Impact of applying composted biosolids on wheat growth and yield parameters on a calcimagnesic soil in a semi-arid region

A field trial in a semi-arid climate was carried out on wheat ( Triticum aestivum var. Marchouch) growing on a calcimagnesic soil using compost applied at 42 T/ha during the three years of study, but in different ways: C1, C2 and C3. Over this period, the level of total Kjeldhal nitrogen (TKN) increased in the soil amended by high doses (C2 and C3, by about 33 and 50%) compared with steady low amendment (C1) and to both controls NF (soil without fertilisation) and MF (soil receiving mineral fertilization). Adding compost also led to a positive influence on cation exchange capacity (CEC) by increasing humic substance levels (HS) which doubled in plots C2 and C3 compared with both controls. In NF soil, the TKN, total organic carbon (TOC) and the pH of soil showed a clear negative correlation with the agronomic parameters. In the MF soil, most physico-chemical parameters correlated well with the agronomic parameters: input of mineral elements balancing export through harvest. In amended soil, especially in C3 plots, HS and CEC showed significant correlations with most agronomic parameters (P1: 69.1%) due to enhanced CEC and sequestration of available carbon in the form of stable humic structures. Key words: Compost, wheat growth, calcimagnesic soil, semi-arid region.

CARBON BUDGET AND SEQUESTRATION POTENTIAL IN A SANDY SOIL TREATED WITH COMPOST

ABSTRACTThe effects of compost application on soil carbon sequestration potential and carbon budget of a tropical sandy soil was studied. Greenhouse gas emissions from soil surface and agricultural inputs (fertiliser and fossil fuel uses) were evaluated. The origin of soil organic carbon was identified by using stable carbon isotope. The CO2, CH4 and N2O emissions from soil were estimated in hill evergreen forest (NF) plot as reference, and in the corn cultivation plots with compost application rate at 30 Mg ha−1 y−1 (LC), and at 50 Mg ha−1 y−1 (HC). The total C emissions from soil surface were 8·54, 10·14 and 9·86 Mg C ha−1 y−1 for NF, HC and LC soils, respectively. Total N2O emissions from HC and LC plots (2·56 and 3·47 kg N2O ha−1 y−1) were significantly higher than from the NF plot (1·47 kg N2O ha−1 y−1). Total CO2 emissions from fuel uses of fertiliser, irrigation and machinery were about 10 per cent of total CO2 emissions. For soil carbon storage, since 1983, it has been increased significantly (12 Mg ha−1) under the application of 50 Mg ha−1 y−1 of compost but not with 30 Mg ha−1 y−1. The net C budget when balancing out carbon inputs and outputs from soil for NF, HC and LC soils were +3·24, −2·50 and +2·07 Mg C ha−1 y−1, respectively. Stable isotope of carbon (δ13C value) indicates that most of the increased soil carbon is derived from the compost inputs and/or corn biomass. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Effects of long-term mineral fertilization on microbial biomass, microbial activity, and the presence of r- and K-strategists in soil

Long-term effects of mineral fertilization on microbial biomass C (MBC), basal respiration (RB), substrate-induced respiration (RS), β-glucosidase activity, and the r–K-growth strategy of soil microflora were investigated using a field trial on grassland established in 1969. The experimental plots were fertilized at three rates of mineral N (0, 80, and 160 kg ha−1 year−1) with 32 kg P ha−1 year−1 and 100 kg K ha−1 year−1. No fertilizer was applied on the control plots (C). The application of a mineral fertilizer led to lower values of the MBC and RB, probably as a result of fast mineralization of available substrate after an input of the mineral fertilizer. The application of mineral N decreased the content of C extracted by 0.5 M K2SO4 (Cex). A positive correlation was found between pH and the proportion of active microflora (RS/MBC). The specific growth rate (μ) of soil heterotrophs was higher in the fertilized than in unfertilized soils, suggesting the stimulation of r-strategists, probably as the result of the presence of available P and rhizodepositions. The cessation of fertilization with 320 kg N ha−1 year−1 (NF) in 1989 also stimulated r-strategists compared to C soil, probably as the result of the higher content of available P in the NF soil than in the C soil.

Alternatives to Methyl Bromide for Strawberry Runner Plant Production

For years, strawberry (Fragaria ×ananassa L.) runner plant nurseries have relied on methyl bromide (MB) fumigation of soil to produce healthy transplants. Methyl bromide, however, has been phased out due to its environmental risks. The potential for alternative fumigants to replace MB was evaluated at low and high elevation strawberry nurseries in California. The alternative fumigant iodomethane plus chloropicrin (IMPic) and a nonfumigated control (NF) were compared to methyl bromide plus chloropicrin (MBPic) at a low elevation nursery (LEN) and at a high elevation nursery (HEN) near Susanville, Calif. At a HEN near Macdoel, Calif., MBPic was compared to alternative fumigants IMPic, 1,3-dichloropropene plus chloropicrin mixture (Telone C35) followed by dazomet, chloropicrin (Pic) followed by dazomet and NF. Plants produced at the LEN were transplanted at the Macdoel HEN to measure the effects of soil fumigant history on plant health and runner plant production. Plants produced at both high elevation nurseries were evaluated for fruit yield and quality at two commercial fruit production sites in soils previously fumigated with MBPic or Pic. Runner plant production at the nurseries was similar in plots fumigated with either MBPic or alternative fumigants. All fumigation treatments had higher runner plant production than plants produced for two production cycles on NF soils. Generally, fruit yields from nursery plants produced on soils fumigated with IMPic, Pic followed by dazomet, or Telone C35 followed by dazomet, were similar to fruit yields from plants produced on MBPic fumigated soils. Overall, our results indicate that preplant soil treatments with IMPic, Pic followed by dazomet, and Telone C35 followed by dazomet, are potential alternatives to MBPic fumigation for strawberry runner plant nurseries. Fruit yields by plants in MBPic and Pic fumigated soils were comparable; however, they were more variable in Pic fumigated soils. Chemical names used: 1,3-dichloropropene (1,3-D), methyl bromide, methyl iodide (iodomethane), trichloronitromethane (chloropicrin), tetrahydro-3, 5-dimethyl-2 H-1,3,5-thiadiazine-2-thione (dazomet).

Effect of Fertilization Methods on Biomass, Oil Yield and Economics in Geranium (Pelargonium sp.) in India

Field studies on sprinkler fertigation with normal (NF) and water soluble (WSF) NPK fertilizers in geranium were conducted at the University of Agricultural Sciences, Bangalore with ten treatments replicated thrice over two years. Cumulative herbage yield of 51 and 53 t/ha in controls were increased (6l, 67 and 70 t and 61.71 and 74 t) with 50, 75 and 100% NF and WSF fertigation. Correspondingly, the oil yield also increased (62.5 and 62 kg to 72, 79 and 88 kg and 76, 87 and 90 kg). These improvements in yields were caused by better growth responses such as plant height and spread and the number of shoots. These growth improvements were influenced by greater uptake efficiencies of N (from 28–34%) and P (from 20–27%). Soil applied 100% NF with surface or sprinkler irrigation had 70 or 60 t herbage and 83 or 91 kg oil per hectare. Application of 75% WSF fertigation was similar to 100% NF soil application with surface irrigation on herbage and oil yields. A net profit of $3,014.50 (Rs. 0.15, 0.154 and 0.159 million) with fertigation at 100% WSF or NF and 100% soil application with sprinklers, respectively may be obtained

Calculation of a strip foundation on a base of finite depth with consideration of creep : Kakosimidi, NF Soil Mech. Found. Engng, V12, N3, 1975, P196–200

Calculation of a strip foundation on a base of finite depth with consideration of creep : Kakosimidi, NF Soil Mech. Found. Engng, V12, N3, 1975, P196–200