This study evaluated inexpensive alternatives for the determination of total N in plant and soil samples. Plant and soil samples which varied widely in N concentration were digested in a 126‐sample‐capacity Al block digester followed by determination of total N with the ammonium electrode in a semiautomated reaction vessel assembly. The proposed Ammonium electrode semiautomated (AES) procedure was compared to standard micro‐Kjeldahl and aluminum block digested‐steam distilled‐titrated (ABDDT) procedures. Thirty to 50 more samples could be analyzed per 8‐hour day with the proposed semiautomated procedure as compared to standard micro‐Kjeldahl methods. The precision of the methods were comparable but significantly more N was found by using the ABDDT procedure.

Yield response to foliar fertilization (N, P, K, S, solution) of soybeans [Glycine max (L.) Merr.] in Iowa has stimulated interest in the use of the same or similar materials in other soybean production areas. Inconsistent yield increases were obtained in Iowa, and it is unknown whether foliar fertilization is feasible where environmental conditions, type of soybeans, and other factors are different from those in Iowa. Field experiments were conducted on a Tifton sl (fine‐loamy, siliceous, thermic, Plinthic Paleudult) and on a Norfolk sl (siliceous, thermic, Typic Paleudult) in the Coastal Plain region of Georgia. Urea K‐polyphosphate mix (urea, K‐polyphosphate, and K2SO4) and NH4‐polyphosphate mix (urea, NH4‐polyphosphate, KCl, and K2SO4) treatments were foliar sprayed on soybeans during the seed filling period. All spray treatments damaged the foliage and suppressed yields with the greatest damage to foliage occurring with repeated application of foliar fertilizer. Three sprayings of a mixture containing 28, 2.9, 9.5, and 1.7 kg N, P, K, and S/ha resulted in an average (two sites) yield decrease of 10.9% for the K‐polyphosphate mix and 17.6% for the NH4‐polyphosphate mix. Weight of pods, whole plants, or seeds, and seed quality were not affected by spray treatments. Absorption of applied nutrients into leaf tissue and translocation to reproductive tissue were detected only in a few instances. Increased N levels were detected only in seeds, and P levels increased only in leaves, while K levels were not changed. Under the conditions of this study, foliar N, P, K, and S fertilization of soybeans does not appear practicable for increasing yields.

Effects of additions of sewage sludge from a highly industrialized area of Atlanta, Georgia, N‐P‐K inorganic fertilizers, selected heavy metals, and trace elements were made on 3 by 9 m plastic‐divided plots sodded to fescue (Festuca arundinacea Schreb.) to evaluate accumulations and movement patterns in the soil. Fescue yields and elemental content were also determined. Soil samples taken 17 weeks after the initial sludge treatment showed only slight increases in Cd, Cr, Cu, Pb, and Zn content. One year later (72 weeks after the initial treatment), two additional applications of sewage sludge (a total of 16.8 metric tons/ha had increased the levels of these elements in the surface 7.5‐cm soil layer approximately 7, 3, 4, 4, and 5 times, respectively. The Zn content was the highest (88 ppm), followed by Pb (12 ppm), Cu (3.2 ppm), Cr (2.0 ppm), and Cd (1.4 ppm). Adding selected elements to the sewage sludge, even at relatively high levels, resulted in little movement of Zn lower than 30 cm and other heavy metals lower than 15 cm.Forage yields over the 2‐year period were increased, over control plots, approximately 30% by the sewage sludge and 150% by N‐P‐K fertilizer.The sewage sludge additions significantly increased the heavy metal and P contents in fescue, but not of K, Ca, and Mg. The greatest increase was from 33 to 1,419 ppm of Zn as an average of 8 sampling periods. No toxic or detrimental effects on fescue were noted.

Manganese deficiency is known to severely reduce growth and yield of soybean [Glycine max (L.) Merr.] plants, but little is known about the effects of Mn deficiency on soybean seed quality factors. Seed from field‐grown soybean plants containing leaf Mn concentrations ranging from 4 to 58 ppm were analyzed for oil and protein percentage. Seed oil and seed protein from selected treatments containing 4 to 44 ppm leaf Mn were analyzed for fatty acid and amino acid percentages, respectively.Severe Mn deficiency (less than 15 ppm Mn in the leaves) increased seed protein percentage and decreased seed oil percentage. Seed from plants with extremely low leaf Mn levels contained higher percentages of linoleic, palmitic, linolenic, and stearic acids and a lower percentage of oleic acid. The percentages of seed protein, seed oil, and fatty acids changed markedly at low leaf Mn levels but remained relatively constant above leaf Mn concentrations of 15 to 20 ppm. Percentages of amino acids in seed protein were relatively unaffected by Mn.The results show that several soybean seed quality factors can be markedly altered by deficient levels of Mn. These changes could have a significant influence on the quality of products derived from soybean seed.

This study was conducted to determine the effect of nitrogen and boron on protein and oil percentages and fatty acid composition of corn (Zea mays L.) grain. In one study, two rates (90 and 180 kg/ha) of nitrogen, two periods (December and preplant), with and without a nitrification inhibitor were applied to corn on a Norfolk loamy sand soil in the Coastal Plain region of Georgia. In a second study, three rates (0.28, 0.56, and 1.12 kg/ha) of boron were applied to the same soil as for study one. Check plots with no treatment were included in each experiment. Grain samples from each plot were analyzed for protein and oil percent by standard A.O.A.C. methods and the fatty acid composition of oil was determined by gas‐liquid chromatography. Protein percent increased with increasing rates of N without any effects from time of application or of the nitrification inhibitor. Nitrogen had no effect on oil percent or oil composition. Boron fertilization had no effect on any of the chemical characters measured in this study.