A study was conducted to determine the effect of surface soil thickness on yields of corn and to learn whether nitrogen fertilizer would substitute for surface soil thickness in producing yields of corn on the minimal Brunizem soils of southwestern Iowa. During 1957 and 1958, 55 nitrogen fertilizer experiments were distributed over the existing range of surface soil thickness. The corn yield obtained from each of 5 nitrogen fertilizer rates was measured at each site. By means of a multiple regression analysis it was found that application of nitrogen fertilizer at the rate of 100 pounds per acre for corn completely substituted for surface soil in 1957 but failed to do so in 1958. Under the soil and climatic conditions that prevail in the area studied, nitrogen fertilizer can substitute completely for surface soil thickness in some years but not in others. Apparently, climatic factors influence the degree of such substitution.

An analysis system is described by means of which the carbohydrates of plant materials are successively dissolved, hydrolyzed, and determined as reducing sugars. The uronides are determined on a separate sample. In this manner 7 groups are obtained: 1) monosaccharides, 2) di-, and oligosaccharides. 3) fructosan, 4) starch. 5) hemicellulose, 6) cellulose, 7) uronides. The final hydrolysis residue from the carbohydrate hydrolysis is considered as lignin. Furthermore, crude fat, crude protein, ash, and in cold water soluble N-free non-carbohydrate organic matter are determined. The total of the results of the analyses appears to be approximately 100 %. In an alternative system used by the author, mono-, di-, and oligosaccharides and fructosan are determined as a group. The results are compared with those obtained by fractionation. The sugar solutions have been purified and neutralised with ion-exchange resins using the bath-method. Duolite A-7 and Duolite C-3 have been found to be suitable for these purposes in experiments which were made with pure solutions of individual sugars. The purity of different fractions of carbohydrates has been checked by paper chromatography. Also the proportions of individual monosaccharides in a hemicellulose fraction for a more exact calculation of their value for hemicellulose were estimated by chromatography.

A description is given of an apparatus with the aid of which the modulus of dynamic elasticity of fibers can be determined at about 1000 cycles/sec. as a function of the strain. In principle the dynamic elasticity constant of the fiber is determined by measuring the resonance frequency of a cantilever spring which is loaded with the fiber. The results of measurements on various types of natural, regenerated, and synthetic fibers are given.

An analysis system is described by means of which the carbohydrates of plant materials are successively dissolved, hydrolyzed, and determined as reducing sugars. The uronides are determined on a separate sample. In this manner 7 groups are obtained: 1) monosaccharides, 2) di-, and oligosaccharides. 3) fructosan, 4) starch. 5) hemicellulose, 6) cellulose, 7) uronides. The final hydrolysis residue from the carbohydrate hydrolysis is considered as lignin. Furthermore, crude fat, crude protein, ash, and in cold water soluble N-free non-carbohydrate organic matter are determined. The total of the results of the analyses appears to be approximately 100 %. In an alternative system used by the author, mono-, di-, and oligosaccharides and fructosan are determined as a group. The results are compared with those obtained by fractionation. The sugar solutions have been purified and neutralised with ion-exchange resins using the bath-method. Duolite A-7 and Duolite C-3 have been found to be suitable for these purposes in experiments which were made with pure solutions of individual sugars. The purity of different fractions of carbohydrates has been checked by paper chromatography. Also the proportions of individual monosaccharides in a hemicellulose fraction for a more exact calculation of their value for hemicellulose were estimated by chromatography. | Selostetussa analyysijärjestelmässä on hiilihydraatit asteettain liuotettu ja hydrolysoitu sekä määritetty pelkistävänä sokerina. Uronidit on määritetty eri näytteestä. Täten on saatu seitsemän ryhmää 1) monosakkaridit, 2) di-ja oligosakkaridit, 3) fruktosaanit, 4) tärkkelys, 5) hemiselluloosa, 6) selluloosa, 7) uronidit. Hiilihydraattimääritysten lopullinen hydrolyysijäännös on katsottu ligniiniksi. Lisäksi on määritetty raakarasva, raakaproteiini, tuhka sekä kylmään veteen liukeneva typpi- ja hiilihydraattivapaa orgaaninen aine. Analyysitulosten yhteissumma on erilaisilla rehuaineilla osoittautunut olevan melko lähellä prosenttilukua 100. Vaihtoehtoisesti on menetelty myös siten, että mono-, di- ja oligosakkaridit sekä fruktosaanit on määritetty yhteismäärityksenä ja tulosta verrattu fraktioimalla saatuun. Sokeriliuosten puhdistaminen ja neutraloiminen on suoritettu ioninvaihtajilla. Duolite A-7 ja Duolite C-3 on kokeissa todettu tarkoitukseen sopiviksi. Fraktioiden puhtautta on tarkkailtu paperikromatografian avulla. Kromatogrammeista on myös arvioitu laskua varten eri monosakkaridien osuus hemiselluloosafraktiossa.

The effects of aluminum in solution cultures on growth of sunflower plants and uptake of boron and calcium were determined under greenhouse conditions. Measurements were made of plant height and weights of roots and tops. Total amounts of aluminum, boron, and calcium in the roots and tops were determined. Aluminum in concentrations above 4 ppm. drastically reduced heights of plants and weights of tops and roots. Increases in concentration of aluminum had no effect on amount of boron in tops or roots. There were no significant effects from aluminum on amount of calcium found in tops. However, the amount of calcium in roots decreased as concentration of aluminum in solutions increased. Aluminum accumulated in large amounts in roots of sunflower plants, but there was no increase in the aluminum contents of tops as aluminum concentration in the solutions increased.

The response of Bartlett pear trees to fertilizers is of continuing interest to pear growers in California. An extended series of trials to obtain facts with respect to this relationship was conducted in all of the major pear producing areas in the state. Immediate objectives varied among the trials but, in each case, response in yield to the application of nitrogen was determined.

Evaluation of soil moisture changes with the neutron method agreed closely with that obtained from the weighing lysimeters. Evapotranspiration can be determined with either method by the equation ET = P - G - Q ± Δ M where ET = evapotranspiration, P = precipitation, G = percolation, Q = surface runoff and ΔM = change in soil moisture. Differences were shown in the soil moisture extraction pattern under deep-rooted and shallow-rooted meadow crops. The hydrologic implications of this difference are discussed.

The ratio of daily evapotranspiration to net radiation was determined at various stages in the development of a corn crop. Measurements, made near the center of a 266- by 340-foot corn plot near Guelph, Ontario are reported for 16 days of observation during the summer of 1958. Soil moisture in the plot was maintained at a level exceeding 75% available. There was good agreement between the daily evapotranspiration determined by a floating lysimeter and the daily evapotranspiration computed hourly from the vertical heat budget method. The ratio of evapotranspiration to net radiation (E/Rₙ) averaged 0.81 ± .09 for the daytime period on days following rain when a large area was equally moist. Low values of E/Rₙ were associated with days of heavy cloud and high humidity. Values of E/Rₙ greater than unity during the daytime were obtained on some days when the corn plot was irrigated and the surroundings were dry. Freezing of the crop reduced E/Rₙ to 0.52. The stage of crop development prior to freezing did not have any effect on E/Rₙ under the soil moisture conditions of this experiment.

A list is given of the ciliates determined to species, collected in the streams, ditches, pools and puddles of the campus of the University of Costa Rica. | Se da una lista de los ciliados que se han podido identificar en muestras de agua coleccionadas de acequias, caños, estanques y charcos de la Ciudad Universitaria de Costa Rica. Con ello se pretende contribuir al conocimiento de la fauna protozoológica del país, la que es hasta el momento prácticamente desconocida.

A general solution for the efficiency of a single winding spindle is given, where the patrolling time of the automatic knotting unit may be less than the unwinding time of the supply bobbin. Constant supply bobbin unwinding times and random yarn breaks are assumed in obtaining the solution, which is modified to allow for "doffing" and servicing times. The case where different winding spindles are allocated to supply bobbins having different unwinding times is considered, and the patrolling time giving the maximum combined spindle efficiency is determined by means of a simple arithmetic technique.