1. An account is given of the occurrence of copper deficiency in crops grown on the Fenland peats and glacial sands of East Anglia. Copper deficiency in the crops appears to be due to actual deficiency of available copper in the peat and sandy soils. The level of copper extracted from soils by an acid solution (pH 4.0) of the ammonium salt of E.D.T.A. provides a useful indication of soils deficient in copper, though the occurrence of the deficiency and its severity in crops is influenced by other soil factors, level of water-table in peats, species of crop and weather during the growing season.2. Of the crops grown on the peat and sandy soils of East Anglia the most susceptible to copper deficiency are cereals. Visual symptoms of deficiency are described as these provide an important aid in diagnosis.

The peat fenlands, including areas where much of the original peat has disappeared, cover about 350,000 acres. At the present time, the land is almost wholly in arable cultivation, the main crops being potatoes, wheat and sugar beet. Potatoes have been the most important crop for more than 50 years and on most farms provide the largest cash return and receive the heaviest manuring.The first part of the paper describes the soils of the peat fenlands, gives a simple method of classification, and shows how the different kinds of soil are related to the maturity and progressive wastage of the peat. The remainder of the paper gives the results of a series of thirty-eight manurial experiments on potatoes on the three main kinds of soil and relates the effects of fertilizers to the manurial requirements of this crop as determined by chemical analysis of the soils.

SummaryThe fen silts bordering the Wash are among the most important soils for crop production in eastern England. Derived from marine alluvial deposits occurring naturally or as a result of reclamation, they form deep almost stoneless soils containing little coarse sand but much fine sand and silt.Seven textural classes, ranging from loamy fine sand to silty clay, can be distinguished, but these can be grouped into (1) light silts, typically deep very fine sandy loams with a large available water-holding capacity but weakly developed structure; (2) medium silts, silty loams; and (3) heavy silts, silt loams or silty clay loams, less porous and more retentive of moisture than the light silts.Formerly under grass, the silts were at first capable of growing good crops of potatoes with P fertilizer alone, but as their organic-matter content decreased, potatoes became increasingly responsive to N.In 18 potato manurial experiments on silt soils in Holland, Lincolnshire, done between 1953 and 1963, the mean response to N was much larger than on most English soils, but response differed greatly from site to site and year to year; in most trials N was particularly effective in increasing tuber size and yield of ware. With long-continued use of P fertilizer, residues have accumulated and, particularly on light and medium silts, responses were quite small and differed little between sites; P tended to increase tuber numbers, and so to decrease ware percentage. Most silt soils are rich in K, and only small responses to K fertilizer can be expected, but on a few sites on the light silts, identified by soil analysis as being comparatively poor in K, potatoes responded well. Using these experimental results, recommendations are given for the manuring of potatoes on silt soils.Cooking tests showed little consistent effect of manurial treatment on the amount or degree of tuber blackening.