Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Cu  (2)
  • Enzyme activity  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 28 (1999), S. 253-258 
    ISSN: 1432-0789
    Keywords: Key words Grazing animals ; Enzyme activity ; Microbial biomass ; Pasture ; Soil organic matter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The size and activity of the soil microbial biomass in grazed pastures was compared on the main grazing area and on stock camp areas where animals congregate. Two sites were on hill country and three on gently sloping border-dyke irrigated land. Due to the transfer of nutrients and organic matter to the camp areas via dung and urine there was an accumulation of soil organic C, organic and inorganic P and S and soluble salts in the camp areas. Soil pH also tended to be higher in camp areas due to transfer of alkalinity by the grazing animals. Water soluble organic C, microbial biomass C and basal respiration were all higher in soils from camp areas but the proportion of organic C present as microbial C and the microbial respiratory quotient were unaffected. Microbial activity as quantified by arginine ammonification rate and fluorescein diacetate (FDA) hydrolysis was higher in camp than non-camp soils but dehydrogenase activity remained unaffected. Activities of protease, histidase, urease, acid phosphatase and aryl-sulphatase were all higher in stock camp soils. The activities of both histidase and aryl-sulphatase were also higher when expressed per unit of microbial biomass C, indicating that the increased activity was the result of increased enzyme production by the microbial community. Prolonged regular applications of dairy shed effluent (diluted dung and urine from cattle) to a field had a similar effect to stock camping in increasing soil organic matter content, nutrient accumulation and soil biological activity. It was concluded that the stock camping activity of grazing animals results in an increase in both the fertility and biological activity in soils from camp areas at the expense of these properties on the main grazing areas.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0789
    Keywords: Earthworms ; Enzyme activity ; Microbial biomass ; Pasture ; Soil organic matter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We investigated the quantity and distribution of organic C, microbial biomass C, protease, arylsulphatase and arylphosphatase activity, and earthworm numbers and biomass in the soil from a 37-year-old grazed pasture supplied with superphosphate at rates of 0, 188, and 376 kg ha-1 annually. The results were compared with a non-irrigated wilderness site which had not been used for agriculture and an arable site that had been intensively cultivated for 11 consecutive years. In the 0- to 5-cm layer, organic C followed the trend arable〈wilderness = control〈low phosphate = high posphate and soil biological activity generally followed a similar trend. For example, protease and arylsulphatase activity and microbial biomass C followed the order arable〈wilderness〈control〈low phosphate = high phosphate. The greater activity in the control than the wilderness site was attributed to the more regular turnover of organic matter throughout the year in the control due to the activity of the grazing animals. Earthworm numbers increased in the order arable〈wilderness〈control〈low phosphate〈high phosphate. In the improved pasture sites the earthworm population was dominated by Aporrectodea caliginosa (77–89% of total numbers) although Lumbricus rubellus made an increasing contribution to the population with increasing superphosphate rates. In the unirrigated wilderness site the population consisted of 56% A. caliginosa and 44% L. rubellus. While Octolasion cyaneum and A. rosea made up a small proportion of the population in the improved pasture sites, they were not present in the wilderness or arable sites. A. caliginosa was the only species present in the arable site. The mean fresh weight of individuals followed the order arable〈control = low phosphate = high phosphate〈wilderness and the proportion of jeveniles in the population was greatest in the arable and lowest in the wilderness site.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 74 (1983), S. 111-122 
    ISSN: 1573-5036
    Keywords: Acid soils ; Chelating agents ; Cu ; DTPA ; EDTA ; Fe ; Mn ; Zn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The practice of buffering the pH of the extracting solution to neutrality or above when estimating available micronutrients with the 0.005M DTPA and 0.04M EDTA soil tests was studied using a number of soil samples from a liming experiment. Generally the soil constituted a better buffer system than the commonly used buffers (e. g. ammonium hydroxide, 1M ammonium acetate or 0.1M TEA). Raising the pH of extraction above that of the soil generally altered the quantitites of micronutrients extracted with 0.005M DTPA but had little effect on those extracted with 0.04M EDTA. In further experiments, using a number of acid soils, the effect of adjusting the pH of the extraction system, over the range 4.5 to 7.5, on the quantities of micronutrients extracted by 0.005M or 0.04M DTPA and EDTA was examined. For some soil samples the use of the 0.005M concentration of chalate resulted in a marked peak in extractable Mn, and to a lesser extent Cu, in the range 5 to 6. This was attributed to secondary interactions among cations, Al3+ and Fe3+ at low pH and added Ca2+ at high pH, affecting the quantities of micronutrients being extracted. For a sample of peat, the quantities of Zn, Cu and Mn extracted with 0.005M DTPA or EDTA behaved irregularly as the pH was increased. The strong complexing ability of organic matter may have contributed to such trends. Raising the concentration of the chelate from 0.005M to 0.04M overcame much of the pH-dependent variability in micronutrient extractability since the quantities extracted from all soils generally decreased with increasing pH. It was concluded that the 0.005M DTPA soil test is not suitable for use over a wide range of soil pH values; particularly where the availability of Mn and Cu are important.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 95 (1986), S. 327-336 
    ISSN: 1573-5036
    Keywords: Acidification ; Extractable micronutrients ; Fe ; Mn ; Zn ; Cu ; Extractable P ; Exchangeable cations ; Ca ; Mg ; K ; Na ; Mineral N
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effects of soil acidification (pH values from 6.5 to 3.8), and subsequent leaching, on levels of extractable nutrients in a soil were studied in a laboratory experiment. Below pH 5.5, acidification resulted in large increases in the amounts of exchangeable Al in the soil. Simultaneously, exchangeable cations were displayed from exchange sites and Ca, Mg, K and Na in soil solution increased markedly. With increasing soil acidification, increasing amounts of cations were leached; the magnitude of leaching loss was in the same order as the cations were present in the soil: Ca2+〉Mg2+〉K+〉Na+. Soil acidification appeared to inhibit nitrification since in the unleached soils, levels of NO 3 − clearly declined below pH 5.5 and at the same time levels of NH 4 + increased greatly. Significant amounts of NH 4 + and larger amounts of NO 3 − , were removed from the soil during leaching. Concentrations of NaHCO3-extractable phosphate remained unchanged between pH 4.3 and 6.0 but were raised at higher and lower pH values. No leaching losses of phosphate were detected. For the unleached soils, levels of EDTA-extractable Mn and Zn increased as the soil was acidified whilst levels of extractable Fe were first decreased and then increased greatly and those for Cu were decreased slightly between pH 6.5 and 6.0 and then unaffected by further acidification. Significant leaching losses of Mn and Zn were observed at pH values below 5.5 but losses of Fe were very small and those of Cu were not detectable.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...