A study designed to determine the effect of nitrogen top-dressing on plant characteristics, yield, and protein content of winter wheat was undertaken at Kansas State College in the spring of 1944. Nitrogen fertilizer was applied prior to March 15 to strips of winter wheat in the permanent fertility plots. Yield, protein content, and other data were collected from the top-dressed and the untreated areas. The results indicated that spring applications of nitrogenous fertilizers increased the yield and also increased the protein content. The increases in yield were especially prominent on the plots which were adequately supplied with phosphate. Analysis of several plant growth characteristics indicated that much of this increase could be accounted for by increased tillering and by increased number of kernels per head. Other plant characteristics, such as kernel weight, had little, if any, effect on the increased wheat yields.

The investigation was undertaken to study the possible effects of fertilizers and cropping systems on the quality of grain protein as measured by total content and proportions of nine essential amino acids. Amino acid determinations were made on acid hydrolysates of ground grain using a microbiological assay method. All grains were grown on sulfur-deficient gray wooded soil. Most of the samples were from plots originally laid out in 1930 for long term tests to compare the effects on crop yields of various fertilizers applied in a wheat-fallow cropping system and in a rotation in which mixed legume hay was grown in two years out of five. The protein content of wheat grown in the rotation was higher than that of wheat from the wheat-fallow plots and the barley grown the first year after legumes contained more protein than that grown the third year after legumes. Increases in percentage of protein (N × 6.25) in the grains were associated with some decrease in quality as measured by the percentage that nine essential amino acids contributed to the protein. This decrease in quality was less marked in grains from rotation plots to which fertilizers containing sulfur were applied than in those from plots treated with fertilizers that did not supply sulfur.

The adsorption of Ca, Mg, K and Na by metabolically inactive H-roots of wheat and alfalfa in relation to the nature of the anion has been studied. Titration curves and fH values showed wheat roots to have a weaker acid character than alfalfa roots. A high retention of H⁺ over metal cations was indicated. As a consequence, only small amounts of cations were adsorbed when offered as nitrates, but large amounts were adsorbed when offered as the bicarbonates. The order of increasing adsorption in either case was: Na, K, Mg, Ca. When Ca, Mg and K were offered in exchangeable form on a soil colloid with Ca/Mg and Ca/K ratios of 4, the Ca/Mg ratios on the roots were 4 and 8, and the Ca/K ratios were 10 and 24 for the wheat and alfalfa roots, respectively. The corresponding distribution of cations on the wheat roots were: Ca, 73%; Mg, 19%; K, 8%; and for alfalfa roots they were: Ca, 85%; Mg, 11%; and K, 4%. It is concluded that the adsorption of cations by metabolically inactive roots is a neutralization reaction involving principally Ca. The group of compounds involved in this reaction have been designated as RCOOH. Selective adsorption of cations involving exchange reaction, notably Mg and K, through RH is restricted to metabolically active roots. It is suggested that the proportions of K to Ca entering the plant is related to the concentration and proportion of RH to RCOOH of roots.

v | ok | Kirjasto Aj-k | On the shrivelheads of spring wheat and their causes in Finland

Four wheat and three oat fertilizer experiments were established at various locations in the eastern half of Kansas for the crop year 1950–51. Objectives of these experiments were to obtain information (1) relative to the best time, rate, and method of applying nitrogenous fertilizers to wheat and oats, and (2) concerning the use of phosphorus and potassium in combination with various rates of nitrogen. Each experiment consisted of four factorially designed randomized blocks. Rates of nitrogen used were 0, 25, 50, and 100 pounds per acre; rates of available phosphoric acid were 0 and 50 pounds per acre; and rates of potash were 0 and 25 pounds per acre. Chemical analyses of the soils were made. Yield data were analyzed statistically and comparisons were made. Significant yield differences between treatments were obtained for each experiment. Greatest increases in yield of wheat accompanied the heaviest applications of nitrogen with the single exception of one location which recently had been in alfalfa. The application of both phosphorus and potassium increased the yield of wheat appreciably at this location, most of the increase being due to phosphorus. The application of potash increased the yield appreciably where no ammonium nitrate was supplied. Significant increases in yield of oats were obtained at each location following the application of 50 pounds per acre of nitrogen. The inclusion of phosphorus and potassium in the fertilizer did not affect oat yields very much. The time of application of nitrogen generally had little influence on yields of either wheat or oats. From an economical standpoint, application of all the nitrogen at seeding time might be preferable.

Moisture available to wheat, potatoes, tomatoes, and sweet corn was determined by combining moisture retaining characteristics of soils, and depths to which crops exploit the water reservoir. Soil types on which some or all of the crops were grown included Sassafras and Nixon loams, Penn silt loam, and Collington loamy sand. Available water in a unit depth varied with soil type and with horizon in a given soil type. Effective rooting depth of a crop was defined as the maximum depth to which soil continued to lose moisture after a prolonged period of rainless weather. Moisture samples determined gravimetrically were each referred to a standard of 100 cm. water tension to give relative wetness values. When depth vs. relative wetness was plotted, effective rooting depth was a clearly defined point below which insignificant quantities of water were obtained by plants. Effective rooting depth of sweet corn varied with soil type from 11 to 35 inches. It also varied on a given soil with kind and age of crop. When differences in rooting depth were combined with moisture in unit depth, tomatoes had about four times as much water at their disposal in Sassafras loam as in Nixon loam. Wheat had less than half as much as tomatoes when both were growing on Sassafras loam.