Examination of soils and crops after the inundations of 1 February 1953.1. Salty soils and agricultural crops.

Abstract

Following the sea-water floods in the Netherlands in February 1953, trials were carried out to determine the effect on various flooded crops of the length of the period of inundation and the concentration of salt in the soil moisture (measured after the floods had subsided in April 1953). The concentration of salt in the soil moisture was expressed as a C-value (number of grams of NaCl per litre of soil moisture), measured in the 5-20 cm. layer of soil. Other trials were carried out to determine the effect of the level of the C-value measured in March 1953 on the subsequent growth of spring-sown crops. The duration of flooding, over periods of 1-50 days (with flood water giving post-flood C-values of 0.5-17), had little, effect on the subsequent growth of inundated winter wheat, winter rye and winter barley, but the C-value of the soil had a marked effect. Inundation of winter rye and winter wheat with water giving C-values of 7 or more had an adverse effect on the growth of both crops, more marked in the case of rye than of wheat. The effect of the C-value at the time of sowing on the yield of spring barley was intermediate between that previously recorded in a favourable (wet) growing season, 1946, and an unfavourable (dry) growing season, 1947. See report by C. van den Berg in Versl. Landbouwk. Onderz. 1950, 56, No, 16. The opinion given in the 1950 report, that spring barley cannot be sown at C-values above 10 with expectation of a reasonable (75% normal) yield, was confirmed. The variety Balder was more resistant to salt than Kenia and Saxonia. Kenia barley was sown at intervals from 8 March to 10 May; the effect of the presence of salt in the soil (represented by the C-value measured in March) was progressively adverse with increasingly late sowing. Similar trials with spring oats, sugar-beet, potatoes, flax and peas generally confirmed the results given in the 1950 report on the sensitivity of various crops to the C-value of the soil moisture. The spring-sown crops mentioned above are all less tolerant of salt than spring barley and are arranged in descending order of salt-tolerance. The results of the 1953 trials differed from those of earlier ones in that flax appeared to be less tolerant than previously, probably because of the dry spring in 1953. In 1953, flax did not give 75% normal yield when sown at C-values higher than 2.5. Potatoes, on the other hand, were more salt-tolerant in 1953 than in the earlier trials and gave 75% normal yields when sown in soils with C-values as high as 6. The average C-value of the flooded soils fell rapidly during 1953-4. C-values on very salty soils were 19.5 in March, 1953, 11.8 at the end of the following September and 3.1 by mid-February, 1954. Comparable figures for slightly salty soils were 7.3, 3.4 and 0.7. The rapid decline in salt concentration in the soil moisture during winter 1953-4 is attributed to the application of gypsum in the period September to November, 1953.-W.J.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)