J.N. Ladd

9.9k total citations · 3 hit papers
94 papers, 7.5k citations indexed

About

J.N. Ladd is a scholar working on Soil Science, Environmental Chemistry and Plant Science. According to data from OpenAlex, J.N. Ladd has authored 94 papers receiving a total of 7.5k indexed citations (citations by other indexed papers that have themselves been cited), including 43 papers in Soil Science, 18 papers in Environmental Chemistry and 17 papers in Plant Science. Recurrent topics in J.N. Ladd's work include Soil Carbon and Nitrogen Dynamics (42 papers), Soil and Water Nutrient Dynamics (16 papers) and Soil and Unsaturated Flow (11 papers). J.N. Ladd is often cited by papers focused on Soil Carbon and Nitrogen Dynamics (42 papers), Soil and Water Nutrient Dynamics (16 papers) and Soil and Unsaturated Flow (11 papers). J.N. Ladd collaborates with scholars based in Australia, United States and United Kingdom. J.N. Ladd's co-authors include M. Amato, J.H.A. Butler, D. S. Jenkinson, JM Oades, Johannes A. van Veen, H.A. Barker, M. Van Gestel, Herbert Weissbach, B. E. Volcani and Robert D. Smyth and has published in prestigious journals such as Nature, Journal of Biological Chemistry and Biochemical and Biophysical Research Communications.

In The Last Decade

J.N. Ladd

94 papers receiving 6.7k citations

Hit Papers

Microbial biomass in soil: measurement and turnover. 1972 2026 1990 2008 1981 1972 1985 400 800 1.2k
What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if it has ≥500 total citations, achieves ≥1.5× the top-1% citation threshold for papers in the same subfield and year (this is the minimum needed to enter the top 1%, not the average within it), or reaches the top citation threshold in at least one of its specific research topics.

  1. Microbial biomass in soil: measurement and turnover.
    1981 1.2k citations J.N. Ladd et al. profile →
  2. Short-term assays of soil proteolytic enzyme activities using proteins and dipeptide derivatives as substrates
    1972 874 citations J.N. Ladd, J.H.A. Butler Soil Biology and Biochemistry profile →
  3. Turnover of carbon and nitrogen through the microbial biomass in a sandy loam and a clay soil incubated with [14C(U)]glucose and [15N](NH4)2So4 under different moisture regimes
    1985 368 citations J.N. Ladd, M. Amato et al. Soil Biology and Biochemistry profile →

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
J.N. Ladd Australia 43 4.9k 1.9k 1.7k 1.5k 982 94 7.5k
S. R. Olsen United States 25 3.7k 0.7× 3.7k 2.0× 1.6k 0.9× 825 0.6× 327 0.3× 56 8.2k
Richard P. Dick United States 55 6.6k 1.3× 3.8k 2.0× 2.2k 1.3× 2.2k 1.5× 810 0.8× 189 11.8k
L. Zelles Germany 28 2.9k 0.6× 1.1k 0.6× 827 0.5× 1.9k 1.3× 606 0.6× 61 4.9k
Lars R. Bakken Norway 52 3.8k 0.8× 1.2k 0.7× 2.5k 1.5× 3.7k 2.5× 1.1k 1.1× 123 8.6k
Muhammad Arshad Pakistan 38 2.6k 0.5× 2.0k 1.1× 829 0.5× 780 0.5× 566 0.6× 214 5.5k
R. L. Mulvaney United States 36 2.9k 0.6× 1.7k 0.9× 1.8k 1.1× 1.0k 0.7× 172 0.2× 107 5.1k
Philippe Hinsinger France 48 3.6k 0.7× 6.2k 3.3× 1.3k 0.8× 1.1k 0.7× 428 0.4× 92 10.2k
B. Ceccanti Italy 39 3.3k 0.7× 1.7k 0.9× 660 0.4× 815 0.5× 319 0.3× 114 5.5k
Giancarlo Renella Italy 45 3.1k 0.6× 2.6k 1.4× 993 0.6× 1.7k 1.2× 760 0.8× 115 7.2k
G. J. D. Kirk United Kingdom 43 2.4k 0.5× 3.5k 1.9× 1.1k 0.7× 1.2k 0.8× 190 0.2× 133 6.7k

Countries citing papers authored by J.N. Ladd

Since Specialization
Citations

This map shows the geographic impact of J.N. Ladd's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by J.N. Ladd with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites J.N. Ladd more than expected).

Fields of papers citing papers by J.N. Ladd

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by J.N. Ladd. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by J.N. Ladd. The network helps show where J.N. Ladd may publish in the future.

Co-authorship network of co-authors of J.N. Ladd

This figure shows the co-authorship network connecting the top 25 collaborators of J.N. Ladd. A scholar is included among the top collaborators of J.N. Ladd based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with J.N. Ladd. J.N. Ladd is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Grace, Peter, J.N. Ladd, G. Philip Robertson, & Stuart H. Gage. (2005). SOCRATES—A simple model for predicting long-term changes in soil organic carbon in terrestrial ecosystems. Soil Biology and Biochemistry. 38(5). 1172–1176. 63 indexed citations
2.
Xu, Zhihong, et al.. (1996). Soil nitrogen availability in the cereal zone of South Australia .1. Soil organic carbon, total nitrogen, and nitrogen mineralisation rates. Australian Journal of Soil Research. 34(6). 937–948. 11 indexed citations
3.
4.
Grace, Peter, J.N. Ladd, JO Skjemstad, et al.. (1994). The effect of management practices on soil organic matter dynamics.. 162–171. 15 indexed citations
5.
Cogle, A. L., WM Strong, PG Saffigna, J.N. Ladd, & M. Amato. (1987). Wheat straw decomposition in subtropical Australia .II. Effect of straw placement on decomposition and recovery of added 15N urea. Australian Journal of Soil Research. 25(4). 481–490. 26 indexed citations
6.
Cogle, A. L., PG Saffigna, WM Strong, J.N. Ladd, & M. Amato. (1987). Wheat straw decomposition in subtropical Australia .I. A comparison of 14C labeling and two weight loss methods for measuring decomposition. Australian Journal of Soil Research. 25(4). 473–479. 16 indexed citations
7.
8.
9.
Ladd, J.N., et al.. (1983). Decomposition of plant material in Australian soils. I. The effect of quantity added on decomposition and on residual microbial biomass. Australian Journal of Soil Research. 21(4). 563–570. 35 indexed citations
10.
Ladd, J.N., J. W. Parsons, & M. Amato. (1977). Studies of nitrogen immobilization and mineralization in calcareous soils—I. Soil Biology and Biochemistry. 9(5). 309–318. 106 indexed citations
11.
Batey, T., I. H. Rorison, J. W. Parsons, et al.. (1975). Agriculture group and fertiliser society symposium soil nitrogen and crop growth. Journal of the Science of Food and Agriculture. 26(9). 1425–1432. 1 indexed citations
12.
Ladd, J.N. & J.H.A. Butler. (1971). Inhibition by soil humic acids of native and acetylated proteolytic enzymes. Soil Biology and Biochemistry. 3(2). 157–160. 26 indexed citations
13.
Ladd, J.N. & J.H.A. Butler. (1969). Inhibitory effect of soil humic compounds on the proteolytic enzyme pronase. Australian Journal of Soil Research. 7(3). 241–251. 39 indexed citations
14.
Ladd, J.N. & J.H.A. Butler. (1969). Inhibition and simulation of proteolytic enzyme activities by soil humic acids. Australian Journal of Soil Research. 7(3). 253–261. 47 indexed citations
15.
Butler, J.H.A. & J.N. Ladd. (1969). The effect of methylation of humic acids on their influence on proteolytic enzyme activity. Australian Journal of Soil Research. 7(3). 263–268. 23 indexed citations
16.
Ladd, J.N. & P.G. Brisbane. (1967). Release of amino acids from soil humic acids by proteolytic enzymes. Australian Journal of Soil Research. 5(2). 161–171. 36 indexed citations
17.
Ladd, J.N. & J.H.A. Butler. (1966). Comparison of some properties of soil humic acids and synthetic phenolic polymers incorporating amino derivaties. Australian Journal of Soil Research. 4(1). 41–54. 42 indexed citations
18.
Brisbane, P.G. & J.N. Ladd. (1965). MICROBIOLOGICAL OIL PROSPECTING IN AUSTRALIA. The APEA Journal. 5(1). 191–195. 2 indexed citations
19.
Brisbane, P.G. & J.N. Ladd. (1965). The Role of Microorganisms in Petroleum Exploration. Annual Review of Microbiology. 19(1). 351–364. 14 indexed citations
20.
Ladd, J.N.. (1964). Studies on The Metabolism of Model Compounds Related to Soil Humic Acid I. The Decomposition of N-(O-Carboxyphenyl)Glycine. Australian Journal of Biological Sciences. 17(1). 153–169. 9 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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