Secular and seasonal changes in soils
AuthorsJohn S. Burd
J. C. Martin
Authors AffiliationsJohn S. Burd was Professor of Plant Nutrition; J. C. Martin was Assistant Chemist in the Experiment Station.
Hilgardia 5(15):455-509. DOI:10.3733/hilg.v05n15p455. April 1931.
Abstract does not appear. First page follows.
Variation in Yields of Barley and in Nitrogen Content of Soils
In 1915 there was initiated in this laboratory a series of observations of the effects of cropping and fallowing upon the composition of a considerable number of soils (thirteen) assembled for that purpose. These observations have continued until the present and numerous studies of the data obtained have been made and published from time to time. A unique feature of this work has been the amount of attention paid to the liquid phase and the attempts which have been made to correlate crop production with concentration.
As invariably happens after a number of years in soil experiments where no fertilizers or amendments are used, the soils have attained a condition of relative equilibrium with respect to composition and, in the case of the plots under continuous crop, the yields also now vary but little from year to year.
 Burd John S. Chemical criteria, crop production and physical classification in two soil classes. Soil Science. 1918. 5(5):405-419. DOI: 10.1097/00010694-191805000-00006 [CrossRef]
 Burd John S. Relation of biological processes to cation concentrations in soils. Soil Science. 1925. 20(4):269-283. DOI: 10.1097/00010694-192510000-00002 [CrossRef]
 Burd John S. An important aspect of soil solution research. First International Congress of Soil Science Proceedings and Papers. 1927. 2:1-8.
 Burd John S., Martin J. C. Secular and seasonal changes in the soil solution. Soil Science. 1924. 18(2):151-167. DOI: 10.1097/00010694-192408000-00009 [CrossRef]
 Comber Norman M. The availability of mineral plant food. Jour. Agr. Sci. 1922. 12(Pt. 4):363-369. DOI: 10.1017/S0021859600005748 [CrossRef]
 Hoagland D. R. The absorption of ions by plants. Soil Science. 1923. 16(4):225-246. DOI: 10.1097/00010694-192310000-00002 [CrossRef]
 Hoagland D. R., Martin J. C. Effect of season and crop growth on the physical state of the soil. Jour Agr. Res. 1920. 20(5):397-404.
 Lipman J. G., Blair A. W. Nitrogen losses under intensive cropping. Soil Science. 1921. 12(1):1-19. DOI: 10.1097/00010694-192107000-00001 [CrossRef]
 Martin J. C. Effect of crop growth on the replaceable bases in some Californian soils. Soil Science. 1929. 27(2):123-136. DOI: 10.1097/00010694-192902000-00006 [CrossRef]
 Parker F. W. Soil phosphorus studies: III. Plant growth and the absorption of phosphorus from culture solutions of different phosphate concentrations. Soil Science. 1927. 24(2):129-146. DOI: 10.1097/00010694-192708000-00006 [CrossRef]
 Stewart Guy R. Effect of season and crop growth in modifying the soil extract. Jour. Agr. Res. 1918. 12(6):311-368. DOI: 10.2307/2255713 [CrossRef]