ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Assessment of the relative agronomic effectiveness of phosphate rocks under glasshouse conditions (1993)
    Springer
    Nutrient cycling in agroecosystems 34 (1993), S. 141-151 
    Details
    ISSN: 1573-0867
    Keywords: Dry matter yield ; exchangeable Ca ; phosphate rocks ; P sorption capacity ; relative agronomic effectiveness ; substitution ratio
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Six phosphate rocks (PRs) of varying reactivities were compared with monocalcium phosphate (MCP) in a glasshouse experiment growing perennial ryegrass (Lolium perenne cv. Nui) as the test plant on four soils of contrasting P sorption capacity and exchangeable Ca. The cumulative dry matter yield over 10 harvests showed a significant response to P application in all soils. Based on relative yield and P uptake, MCP was the most effective P fertilizer followed by the reactive phosphate rocks, which were superior to the unreactive rocks in all soils. The relative agronomic effectiveness (RAE) and substitution ratio (SR) of individual PR fertilizers, calculated with respect to MCP using the methods of ‘vertical’ and ‘horizontal’ comparison, respectively, were similar over a range of fertilizer rate. There was a decline or slight increase in the performance of PRs with time in the low P sorption soils but a consistent increase in the high P sorption soils. Some initial influence of exchangeable Ca content of the soils on the relative performance of PRs was also observed. Generally the PRs performed better in high P sorption soils than low P sorption soils and in low exchangeable Ca soils than high exchangeable Ca soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Development and evaluation of an improved soil test for phosphorus. 2. Comparison of the Olsen and mixed cation-anion exchange resin tests for predicting the yield of ryegrass grown in pots (1992)
    Springer
    Nutrient cycling in agroecosystems 33 (1992), S. 135-144 
    Details
    ISSN: 1573-0867
    Keywords: Mixed cation-anion exchange resin P ; Olsen P ; phosphate rocks ; P sorption capacity ; P sources ; Resin P ; ryegrass ; soil testing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A glasshouse experiment was conducted on four soils contrasting in P sorption capacity and exchangeable Ca content with perennial ryegrass using six phosphate rock (PR) sources and a soluble P source applied at four rates (including a control). After three harvests (11 weeks) replicate pots of each treatment were destructively sampled and Olsen P and mixed cation-anion exchange resin (Resin P) extractions carried out. The remaining replicated treatments were harvested another seven times (during 41 weeks). Yields (for the last seven harvests) were expressed as percentages of the maximum yield attainable with MCP. In general, the Resin P test extracted more than twice as much P as the Olsen test. There was a significant increase in Resin P with an increase in the amount of each P source in all four soils, but Olsen P values were not significantly different for soils treated with different rates of each phosphate rock. The abilities of the Olsen and mixed resin soil P tests to predict the cumulative dry matter yield from 7 harvests and the relative yield of ryegrass were compared. Correlations between measured yield (for the last 7 harvests) and soil test for each soil, and relative yield and soil test for all four soils were assessed by regression analysis using Mitscherlich-type models. When dry matter yields were regressed separately against soil test values for each soil, the Resin P consistently accounted for 18–28% more of the variation in yield than did Olsen P. For Resin P a single function was not significantly different from the separate functions fitted to MCP and PR treatments. However, for Olsen P the separate functions for the MCP and PR treatments varied significantly from the single fitted function. The Resin P test (R2 = 0.84) was a better predictor of relative yields over this range of soils than the Olsen test (R2 = 0.75). Two regression models based on the regression of relative yield for MCP treatments against either Olsen or Resin were developed. These models were then fitted to the relative yield data on soils fertilized with PRs only. The Olsen P model was found to be a poorer predictor (R2 = 0.41) than the Resin P model (R2 = 0.73) because it underestimated the observed yield of the PR treatments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01051168
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A simplified resin membrane technique for extracting phosphorus from soils (1990)
    Springer
    Nutrient cycling in agroecosystems 24 (1990), S. 173-180 
    Details
    ISSN: 1573-0867
    Keywords: Phosphate ; resin beads ; resin membranes ; resin-strips ; anion exchange resin ; cation exchange resin ; P sorption capacity ; exchangeable Ca ; phosphate rocks
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A simplified procedure for determining the amount of phosphate (P) extracted from soils by ion exchange resin membranes is reported. Strips of anion (HCO 3 - form) and cation (Na+ form) exchange membrane were shaken with suspensions of soil in deionised water for 16–17 hours. After shaking, the strips were thoroughly rinsed in deionised water before the phosphate retained on the anion exchange resin strip was determined by shaking the strip directly with phosphate reagent. Compared to the common use of resin beads in nylon mesh bags, this resin membrane procedure is simpler, more convenient, and because an elution step is omitted, less time consuming. The mixed resin membrane method for soil phosphate extraction was compared to the use of resin bags on four New Zealand soils, contrasting in P sorbing capacity and exchangeable calcium. The soils were preincubated with and without 240 mg P kg−1 soil with three P sources of different solubilities. The resin strips extracted amounts of P which were closely correlated (R2 = 0.972) with that extracted by the resin bags. The amounts of P extracted by the mixed resin procedure were in proportion to the solubility of the P sources in each soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01073586
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...