AbstractA soil solution displacement method was used to evaluate the effect of CaCO3 on soil retention of sulfate. A decreased amount of sulfate retention was noted with increased rates of CaCO3.By means of a split‐root technique, plants of soybeans (Clycine max (L.) Merrill) and cotton (Gossypium hirsutum L.) were grown in a Dothan subsoil which contained a large amount of adsorbed sulfate, and to which had been added several rates of CaCO3. As CaCO3 rate was increased the uptake of sulfate by five crops of soybeans and one crop of cotton grown successively in the same soil was generally greater. A portion of the adsorbed sulfate in the untreated soil was available, but available sulfate became limiting for the third crop of soybeans and for all successive crops of soybeans and cotton.

Cover title. January 1967. Includes bibliographical references (p. 39). Also available in microfilm under: State agricultural papers.

Cotton and wheat seeds were soaked in various salt solutions (including ammonium phosphates). The seeds were then allowed to germinate. With increasing salt concentration, the germination of cotton did not decrease, whereas the germination of wheat decreased in most cases. Soaking cotton seeds in 0.25m (NH4)2SO4 solutions adjusted to pH levels between 7.2 and 9.0 showed germination injury above pH 7.8. The harmful effect of diammonium phosphate treatment was largely alleviated by subsequent soaking of seeds in dilute solutions of MgSO4. Germination injury from (NH4)2HPO4 appeared to be largely due to the inactivation of Mg in seeds.

AbstractField and greenhouse studies with cotton and wheat showed that fertilizers containing ammonium phosphates were especially detrimental to germination and could result in very poor stands. In order to study the cause of this harmful effect, seeds were soaked in salt solutions (including ammonium phosphates) and acids for various time intervals. The seed surfaces were then washed free of the solutions and allowed to germinate. The (NH4)2 HPO4 solutions reduced germination more than any other salt solution including NH4H2PO4. In studies with cotton seed, a solution of (NH4)2SO4 adjusted with NH4OH to pH 8.2 did not reduce germination as much as did (NH4)2 HPO4. Germination was lowered more by H2SO4 than by H3PO4 at the same pH. Soaking the seed in salt solutions such as CaSO4 before soaking in (NH4)2HPO4 did not improve germination. When the seeds were soaked in MgSO4 or MgCl2 after being soaked in (NH4)2HPO4, there was an improvement in germination as compared with (NH4)2HPO4 alone. Soaking in MgSO4 and MgCl2 did not increase the germination of seed that had been soaked in H3PO4. It appears that the detrimental effect of ammonium phosphate is not due to the ammonium or phosphate ion per se.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFertilizer Nitrogen Sources, Crop Response to Urea and Urea Pyrolysis ProductsG. L. Terman, J. D. DeMent, C. M. Hunt, J. T. Cope Jr., and L. E. EnsmingerCite this: J. Agric. Food Chem. 1964, 12, 2, 151–154Publication Date (Print):March 1, 1964Publication History Published online1 May 2002Published inissue 1 March 1964https://doi.org/10.1021/jf60132a015Request reuse permissionsArticle Views124Altmetric-Citations15LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (450 KB) Get e-Alertsclose Get e-Alerts

SynopsisForage yields of Sart sorghum were increased by either nitrogen fertilizer or irrigation, but a far greater increase was obtained when both were used. Nitrogen content of the plants increased as soil moisture decreased and rate of nitrogen application increased. Closer row spacing increased both forage yield and nitrogen content. Water use increased as the amount of available soil moisture increased.

Caption title. December 1961. Includes bibliographical references (p. 18). Also available on the World Wide Web. Also available in microfilm under: State agricultural papers.

Sulfur has been described as a neglected plant nutrient. In surface soils, sulfur is predominantly in the organic fraction, and native supplies of sulfur vary with the supplies of organic matter, from low to adequate. This native sulfur is supplemented by variable additions from rainwater, irrigation water, atmosphere, fertilizers, insecticides, and fungicides. Although sulfur deficiency under field conditions is not universally a problem, it may be acute in some areas. This probably accounts for the neglect of sulfur nutrition as a general problem for research. Sulfur is also essential in animal nutrition. A complete assessment of sulfur nutrition thus, involves soil, plant, and animal phases and the interrelationships of all three.

Caption title. June 1958. Includes bibliographical references (p. 18-19). Also available on the World Wide Web. Also available in microfilm under: State agricultural papers.

AbstractIn 1930 an experiment was started on a Decatur silt loam and on a Greenville fine sandy loam to compare the effectiveness of different sources of phosphorus for crops grown in a rotation of corn and cotton with vetch. At the end of 16 years, phosphate applications were discontinued in order to study residual effects on yields. In 1950 and 1951, tagged superphosphate was applied to all treatments and available phosphorus, based on P32 uptake, was calculated and expressed as A values.Yield data from both locations show that all sources had considerable residual effects. For any particular source, the residual effect was in proportion to the amounts that had been added. Basic slag gave the greatest residual effect on the Decatur soil as measured by vetch and cotton yields. It also gave the greatest residual effects on the Greenville soil as measured by cotton yields. Tricalcium phosphate and raw phosphate showed a much greater residual effect, as indicated by vetch yields, in the Greenville soil than in the Decatur soil.A values show that all sources had considerable residual effects as measured by radiophosphorus uptake. The A values for basic slag at both locations were larger than for an equivalent amount of any other source. For the Greenville soil, A values show that superphosphate had a greater residual availability than rock phosphate applied at twice the rate of P2O5. However, A values on the Decatur soil indicate that rock phosphate had about the same residual availability as superphosphate applied at an equivalent rate of P2O5. For any particular source, A values were in proportion to the amounts which had been added.Yield data for the first 4 years of the residual period show only a very general relationship with A values when all sources are considered together. However, correlation coefficients show a fairly close relationship between yields and A values in most cases when the analysis is limited to rates of one source.Extractable phosphorus data show that phosphate applications resulted in phosphorus accumulation and that the amount accumulated was proportional to the rate of application.

AbstractGreenhouse studies were carried out to determine the value of seven sources of rock phosphate as compared with superphosphate for production of Sudangrass and Ladino clover on two soils with and without lime. A significant difference was found in the amount of phosphorus available to plants from the various sources of rock phosphate as shown by yields and phosphorus uptake by Sundangrass and Ladino clover. The availability of the seven sources of rock phosphate was affected by both lime and soil type; however, source of rock phosphate was more important than either.In general, the foreign sources of rock phosphate tested, which included Tunis, Morocco, and Curacao Island, were superior to all of the domestic sources of rock phosphate except that of South Carolina. Rock from the latter state was as available as any of the foreign sources of rock phosphate tested.No correlation was found between fluorine content or specific surface of the sources of rock phosphate and their availability to plants. Chemical solubility was a better measure of availability than fluorine content or specific surface.

AbstractThe 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.

AbstractA study was made of the phosphorus status of soils which had received phosphate applications over a period of years to determine the loss of phosphorus by erosion. Phosphorus that could not be accounted for by analysis of the surface 16 inches of soil and by crop removal was assumed to be loss by erosion.Where corn and cotton was used as the rotation, an average of 63% of the phosphorus applied during a 16‐year period to a Hartsells fine sandy loam soil had been lost by erosion as compared to 40% for a corn, cotton, and winter legume rotation. The results show that most of the accumulated phosphorus could be extracted by a HCl‐NH4F solution. Three plots in the corn, cotton, and winter legume rotation contained 7 to 8% of < 2 µ material in the surface 0 to 8 inches originally, but after 16 years of cropping the < 2 µ material had been reduced to 5 to 6%. The clay fraction contained 25 to 30% of the total phosphorus. These results indicate that only a small part of the phosphorus was lost along with the clay fraction. A study of 22 fields in Baldwin County that had been in potatoes from 5 to 30 years shows that the surface soil accumulated an average of 103 pounds P2O5 per acre per year in potatoes, although an estimated 200 pounds of P2O5 was added each year potatoes were grown. An inventory of the phosphorus status of soils in cement bins after 12 years of phosphate applications shows that 80% or more of the applied phosphorus could be accounted for on the basis of soil analysis and crop removal. The plots were enclosed by cement walls which prevented run‐off except during very heavy rains.