Greenhouse assay of fertility of California soils
W. E. Martin
Authors AffiliationsH. Jenny was Professor of Chemistry and Morphology, and Soil Chemist and Morphologist in the Experiment Station; J. Vlamis was Assistant Soil Chemist in the Experiment Station; W. E. Martin was Associate Agriculturist in Agricultural Extension.
Hilgardia 20(1):1-8. DOI:10.3733/hilg.v20n01p001. May 1950.
This issue reports a new pot-culture technique …
… for studying the supply of available nutrients in California soils. The method gives a fairly reliable indication of whether pasture, field crops, and truck crops on a given soil will respond to nitrogen, phosphorus, or potassium application.
In this technique, various combinations of nutrients (nitrogen, phosphorus, and potassium) are added to pot cultures; Romaine lettuce is grown for definite periods; and relative yields are calculated for partial treatments (N + P, N + K, and P + K) on the basis of yield with full treatment (all three nutrients).
Calibration of pot tests with field tests indicates …
… that nitrogen applications can be expected to increase yields of pasture and field and truck crops if the relative yield of the no-nitrogen treatment in pot tests is 30 per cent or less (provided water, other nutrients, and soil conditions are not limiting).
… that phosphorus applications can be expected to increase yields of these crops if the relative yield of the no-phosphorus treatment is 20 per cent or less (with the same proviso).
Among over 450 California soils tested …
… the percentage found to be low in available nitrogen ranged from 48 to 71 in different soil groups (Storie’s classification).
… the percentage low in available phosphorus ranged from about 40 among alluvial soils (groups I and II) to over 70 among claypans and hardpans (groups IV and V). Both highly acidic and strongly basic soils tended to be low in available phosphorus.
… nearly all appeared to be well supplied with potassium for the crops and soils included in the study.
Bingham F. T. Soil test for phosphate. California Agriculture. 1949. 3:11 14
Mitscherlich E. A. Die Bestimmung des Düngebedürfnisses des Bodens. 1930. Berlin: P. Parey. 119p.
Storie R. E., Weir W. W. Manual for identifying and classifying California soil series. 1948. Berkeley, California: Associated Students Store. 58p. (Lithoprint)
Vandecaveye S. C. Biological methods of determining nutrients in soil 1948. pp.199-230. Bear, F. E., et al. Diagnostic techniques for soils and crops. xxii + 308 p. The American Potash Institute, Washington, D.C
Also in this issue:Temperature studies of lilies
Rotating solatron receives more sunlight for plant growth
Controlled-distribution wing for agricultural aircraft
Once-over mechanical harvesting for cucumbers
Planting dates for mechanical harvesting of cucumbers
Effects of citrus nematode—and irrigation—on nutrient concentrations in Navel orange leaves, roots
Major profit factors in dairy management