Oat straw samples were allowed to decompose for periods varying up to 15 months; changes in functional groups and chemical properties followed as a function of time. Carbon increased in the whole residues and decreased in the lignin fraction while hydrogen decreased in both. Selective demethylation occurred in the lignin but methoxyl content of the complete residues remained about constant. Carboxyl groups as determined by esterification increased progressively, accompanied by decreases in hydroxyl. Carboxyl in the lignin fraction was in good agreement with exchangeable hydrogen determined by an iodometric titration procedure in contrast to lack of agreement between corresponding values in the whole residues. Cation exchange capacity of the straw residues and of their lignin component increased as decomposition progressed. Absorption of oxygen by alkaline suspensions of the residues was determined in a Warburg respirometer and found to increase with length of decomposition period. Most of the total oxygen uptake during an arbitrary 8-hour period could be attributed to the lignin fraction. Some chemical properties of organic matter preparations from five soils were compared with corresponding values for the decomposed residues.

There is in the literature a noteworthy lack of sampling methods to be employed in the selection of papaya fruits for genetical improvement purposes. In the present experiment methods applied to melon and watermelon were extended to papaya with good results. The authors tried to correlate the solids content-as determined by a hand refractometer-with total sugars in the fruit. The correlation does exist being significant and positive. A regression equation was worked out; it permits to calculate the total sugar content provided the Brix value determined by the hand refractometer is known. The equation is as follows: a = 0.57 s where a = total amount of sugar as glucose, and s = total solids.

The cation exchange capacities of several profile samples of soils were determined using three different methods. Total exchangeable cations were determined and used as a criterion for evaluating the different methods of determining the exchange capacity. For all soil samples the NH₄OAc method underestimated the exchange capacity and so produced distorted exchange capacity profiles. The Ba(OAc)₂ method gave exchange capacity values which were equal to the sum of exchangeable cations, except with highly acid soils where it gave low values. The BaCl₂-buffer exchange capacity gave values that were nearly equal to the sum of the exchangeable cations for all samples tested. The Ba(OAc)₂ or BaCl₂-buffer methods, in which Ba is replaced by 0.05 N HCl and the Ba determined using an acetylene flame with a model 52 C Perkin-Elmer photometer, cannot be used for some samples because of Ca interference. Some slightly acid soils gave sufficient Ca release during the HCl extraction to interfere in the Ba determination. This interference was removed by washing the soil with HCl before leaching with the BaCl₂-buffer and by replacing the barium with NH₄OAc.

Stability of aggregates to slaking, as determined by wetsieve analyses, failed to account for differences in structural quality between naturally stable and chemically stabilized Christiana silt loam. The treated and untreated soils were equally resistant to slaking, but permeability and seed germination were better in the treated soil. These differences were related to differences in the consistency of the moist aggregates.

A wilt disease of the passion vine ( Passiflora edulis Sims) in Queensland caused by a species of Fusarium was described by McKnight (1951) and the susceptibility of various species of Passiflora to this organism was determined. Cross-inoculation studies with various forms of Fusarium oxysporum commonly found in Queensland were undertaken. The evidence indicates that Fusarium oxysporum forma passiflora n.f. is the causal agent of wilt in the passion vine in Queensland.

The drying twist of a large number of commercial fibers has been determined. In addition, fibers from related plants which are not at present utilized on a large scale were studied. It was found that fibers from four of the twenty families represented by commercially im portant fibers have clockwise drying twists. These were the Linaceae, Urticaceae, Apocynaceae, and Asclepiadaceae. These observations should be useful in fiber identification and in yielding a clue to cell-wall structure.

The sulfate content of a number of Alabama Soils was determined by extracting with various solutions. The sulfate extracted was measured turbidimetrically. Some factors affecting the adsorption of sulfate by soils were studied. About the same amount of sulfate was extracted by neutral sodium acetate solution, sodium acetate buffered at pH 4.8, KH₂PO₄ solution containing 100 ppm. phosphorus, and KH₂PO₄ solution containing 500 ppm. phosphorus. However, 0.1 N HCl solution extracted little or no sulfate. The samples contained only small quantities of water-soluble sulfate except where sulfate had been recently applied. The results show that sulfate is retained to a certain extent by most soils. The subsurface layers usually contain more sulfate and are capable of adsorbing more sulfate than the surface layers. The surface layers of most of the light textured soils did not contain sulfate or show a capacity to adsorb sulfate from solution. The capacity of soils to adsorb sulfate is affected by certain soil treatments. Increasing amounts of superphosphate applied to a Cecil sandy clay loam resulted in decreasing amounts of soluble sulfate. The data show that superphosphate decreased the capacity of this soil to adsorb sulfate from a CaSO₄ solution. Liming also resulted in a decrease in the retention of sulfate. The sulfate adsorption capacity of a number of materials was determined in an attempt to show what fractions of soils may be responsible for the retention of sulfate. The data show that dehydrated Al₂O₃ adsorbed much more sulfate than any of the other materials. The iron minerals adsorbed rather small amounts of the sulfate while the Davidson colloid, kaolinite, and bauxite were intermediate.

Fertility experiments have been conducted with field corn on Everglades Peaty Muck soils in order to determine the required fertilizer program with respect to P₂O₅ and K₂O. Four experiments have been conducted involving potash, phosphate experiments laid out in randomized block designs and nitrogen, potash, phosphate experiments laid out in 3 × 3 × 3 factorial designs. Soils tests were used to determine the P₂O₅ and K₂O levels in the soil and tissue tests were conducted to measure the uptake of these nutrients from the soils. These data have been correlated with yields in order to furnish the necessary information on which to base fertilizer recommendations from the results of soil or tissue tests. The corn showed yield responses to increasing levels of potash in the soil up to values as high as approximately 70 pounds potassium per acre as determined by the soil tests. The yields ranged from 26 bushels per acre at the lowest K₂O levels to 63 bushels at the level of maximum response which produced plants that gave stem tissue tests averaging approximately 5.00% potassium, moisture free basis. Potash deficient corn gave tissue tests as low as 2.72% potassium. Yield responses to applications of superphosphate were obtained up to levels of approximately 8 pounds per acre of water soluble phosphorus as determined by soil tests. Plants showing no phosphate deficiencies gave stem tissue test values in excess of 0.10% of the element, moisture free basis. The assimilation of P₂O₅ was apparently reduced by higher levels of K₂O in the soil and that of K₂O was reduced slightly by higher levels of P₂O₅. The experiments indicate that fertilizer recommendations for field corn on organic soils may be intelligently made on the basis of soil tests which have been previously correlated with growth and yield response.

Areas of four long-time fertility experiments that were planted to oats in 1952 were used to study the effect of different past treatments upon the level of available soil phosphorus. Phosphorus A values, as derived by Fried and Dean, were compared with the Bray soil phosphorus test, and with crop yields as a means of evaluating the soil phosphorus level. The A values appeared to be very satisfactory for this purpose, and correlated significantly with soil test phosphorus values and with oat yields. At three of the four locations, a higher degree of correlation existed between A values and yields than between soil test phosphorus and yields. Phosphorus A values, determined from plant samples harvested at maturity were higher than those determined from an earlier sampling, but did not correlate any better with yields or soil test phosphorus. The 1952 results from the long-time experimental treatments indicated that ordinary superphosphate, concentrated superphosphate, and calcium metaphosphate applied at equal rates of P₂O₅ over a period of years appear to have an equal effect upon the residual level of available soil phosphorus and upon the yield of oats. Fused tricalcium phosphate compared favorably with these materials on an acid soil but was less effective as a phosphate source on a calcareous soil. Rock phosphate applied at equal or higher rates of P₂O₅ was a less effective source at all locations and by all three standards of comparison.