Interactions of Monomeric Silicic Acid with Copper and Zinc and Chemical Changes of the Precipitates with Aging

Precipitates were formed by titrating dilute, acidic solutions of monomeric silicic acid [Si(OH)?] and copper (Cu) or zinc (Zn) to various pH values. Those containing Cu formed above pH 6.0; those containing Zn formed above pH 7.0. Periodically, during 2 years of aging in their mother liquor, the liquid phase was sampled and analyzed and the Cu/Si or Zn/Si molar ratios of the precipitates calculated. The Cu/Si ratios of those containing Cu stabilized readily near 0.78 and were unaffected by pH. The Zn/Si ratios of the Zn-containing precipitates, however, changed as a result of Si enrichment from near 1.80 soon after their formation to near 0.80 after aging 2 years. The systems with the lowest pH changed first and most rapidly and became stabilized within 6 months; those above pH 8.0 changed more slowly. The Zn-containing precipitates gave diffuse X-ray diffraction patterns indicative of a 2:1 layer silicate, whereas those containing Cu were amorphous

Chemical and Physical Properties of Zinc Fertilizer That Affect Their Availability When Applied to Neutral or Calcareous Soils

The widespread incidence of zinc deficiency has resulted in marketing of many zinc-containing fertilizers having a wide spectrum of chemical and physical properties. Boawn (1966) reviewed research on the agronomic effectiveness of many materials used in the Northwest, and discussed factors affecting their abilities to supply zinc to plants. Mortvedt and Cunningham (1971) reviewed the literature dealing with the production, marketing, and use of micronutrient fertilizers. The different zinc fertilizers marketed, their composition, and the agronomic effectiveness and source of supply for some of them have been presented by Diamond (1972). In general, results have shown that almost all materials marketed are satisfactory sources of zinc when finely powdered and well mixed with the soil. Consequently, properties that increase the number of fertilizer particles in a unit volume of soil or increase the effective size of the particles in the soil enhance zinc availability

The Residual Effects of Zinc Fertilization

The residual value of zinc fertilizer applied to Portneuf silt loam near Kimberly, Idaho was determined by three methods, a) DTPA-extractable Zn, b) plant growth and Zn uptake by beans (Phaseolus vulgaris) grown in a field experiment, and c) plant growth and Zn uptake by beans grown in a pot experiment on soil taken from field plots previously fertilized with Zn. The plant growth and Zn uptake data from the field and pot experiments indicate that application of 10 lb Zn/A is adequate for at least three bean crops. DMA-extractable Zn on samples taken in 1983 indicate adequate available Zn for a fourth crop. The soil tests are still above 1 ppm and they decrease slowly with time. Thus, the single 10 lb Zn/A will likely suffice for several more crops. The experiment is being continued

The DTPA-Extractable Iron, Manganese, Copper, and Zinc from Neutral and Calcareous Soils Dried Under Different Conditions

DTPA (diethylenetriaminepentaacetic acid)-extractable Fe, Mn, Cu, and Zn were determined an several neutral and calcareous soils dried at various temperatures. Extractable Fe increased linearly over the drying temperature range 22 to 100°C, whereas Mn increased in an irregular manner. Values for Cu and Zn changed only slightly over this temperature range. Extractability of an four elements increased when fieldmoist samples were air dried; Fe by a factor of 2 to 3, and Mn, Cu, and Zn by a factor of about 1.3 to 1.5. The increases in extractable Fe and Mn appear to result from separate temperature and dehydration effects and are only partially reversible with rehydration and moist incubation. The results of this study indicate that sample handling be standardized for calibration and routine tests before DTPA-extractable Fe and Mn can be used as reliable diagnostic tests for these elements. Close control of drying conditions for Zn and Cu analysis may be desirable but is not as critical as for Fe and Mn

Zinc Deficiency Symptoms of Beans

Zinc deficiency is common (2) on bean plants grown on calcareous Portneuf silt loam in the Magic Valley of southern Idaho. Ten pounds of zinc per acre every third year is recommended for prevention (4). Land leveling or deep plowing brings to the surface the highly calcareous subsoil and intensifies the zinc deficiency problem. Beans grown following sugar beets or high manure or phosphate fertilizer applications are more likely to exhibit zinc deficiency symptoms (4)

Effect of Corn, Sugarbeets, and Fallow on Zinc Availability to Subsequent Crops

Field observations indicated that Zn deficiency of beans (Phaseolus vulgaris L.) was sometimes more severe than expected when grown on fallowed soil that was low to marginal in available Zn. The objectives of this study were to determine the effects of fallow, sugarbeets (Beta vulgaris L.), and corn (Zea mays L.) on Zn availability to subsequent crops grown on a Portneuf silt loam (Durixerollic Calciorthids, coarse silty, mixed, mesic). The sugarbeet and corn plant tops and sugarbeet roots were removed, and 11.2 kg Zn ha-1 was applied on one-half of each plot before fall plowing 25-cm deep. Beans, sweet corn, or potatoes (Solanum tuberosum L.) were planted the following spring. Whole plant samples of beans and sweet corn and potato stems, leaflets, and petioles were sampled for chemical analyses during the growing season. All bean plants were Zn deficient when grown after fallow or sugarbeets but not after corn or where Zn fertilized. Potatoes and sweet corn did not show any Zn deficiency symptoms or any growth responses to Zn fertilization. The average zinc concentration in beans (vegetative development stage, V3) following Corn was 20.5 mg kg-1 compared with 12.5 mg kg-1 following fallow or sugarbeets without Zn fertilization. The average Zn uptake by beans (V3) following corn was 1.3 g ha-1 compared with 0.6 g ha-1 after fallow or suprbeets without Zn fertilization. The Zn uptake after corn was even greater than where 11.2 kg Zn ha-1 was applied to fallow or sugarbeets (1.3 vs. 0.9 g Zn ha-1). Enhanced Zn availability following corn persisted throughout the growing season and into a second bean crop, although at a decreased level. Similar trends occurred with potatoes and sweet corn. Soil DTPA-extractable Zn was not significantly different after fallow, sugarbeets, or corn. These results indicate that Zn deficiency in sensitive crops may be alleviated or prevented depending upon the preceding crop grown, and that factors not measured by DTPA can significantly influence Zn availability

Determination of Mineral Elements in Plant Tissues Using Trichloroacetic Acid Extraction

An extraction method is described for quantitatively determining Mg, K, Na, Zn, and Mn in plant tissues. The tissue is extracted with 2% trichloroacetic acid and the elements are determined on the filtrate by atomic absorption spectrophotometry. Results compare favorably with those determined after wet ashing with nitric and perchloric acids. In addition, trichloroacetic acid extracts the same fraction of P as does acetic acid and quantitatively extracts total Ca from plant tissues not high in oxalate

Nitrogen Sources for Bean Seed Production

Beans (Phaseolus valgaris L.) often respond to N fertilization; however, N fertilization is not practiced for maximum seed production in southern Idaho. This suggests that the symbiotic relationship and/or soil N sources can provide most of the N needed by this legume. Our objective was to evaluate the relative contribution of the symbiotic-nonsymbiotic N sources by studying the effects of N fertilization on the symbiotic N? fixation and seed yields under field conditions. Experiments were conducted on silt loam soils belonging to the Portneuf series (Xerollic Calciortnids). An acetylene reduction (AR) method was used to determine the effect of N fertilization treatments on the relative seasonal Ng (AR) fixation. The symbiotic N? fixation was also estimated by the equation, N? = Nup — (Nl + Nm - Nh) — ?Nf, where Nup is the accumulated N uptake measured near physiological maturity, Nl and Nh are the amounts of soil NO?-N in the root zone before planting and near physiological maturity, Nm is the N mineralized from soil organic N sources, and ? is the recovery of the N fertilizer (Nf) applied. Estimates of the N fertilizer recoveries were obtained from two experiments using 15N-depleted (NH?)?SO?. The symbiotic N? relationship contributed up to 90 kg N/ha, which was 40 to 50% of the total N found in bean plants near physiological maturity. The amount of symbiotic N? fixed decreased as the available soil N or fertilizer N increased, and increased as the N required by the individual cultivars increased. The response to N fertilization depended upon the cultivar, as well as on the N available from soil sources. Measured fertilizer N recoveries ranged from 7 to 33%. An average of 52% of the total N uptake near physiological maturity was taken up after the maximum symbiotic Ng(AR) rate occurred; while the seed contained an average of 60% of the total N uptake. A low N fertilization rate (< 50 kg N/ha) when the soil Nl was low (<50 kg N/ha) ensured an early vigorous plant growth but did not always increase seed yields. Higher N fertilization rates may be required on soils with lower amounts of mineralizable N

A Survey of the Nutrients Status of Sugarbeets Grown in Idaho and Washington

Sugarbeets are a major irrigated crop in Idaho and Washington. In recent years foliar sprays of several nutrient elements, especially the micronutrients, have been recommended by commercial consultants and applicators. As a result, many acres not only of beets but other crops as well have received foliar sprays containing one or more nutrient elements. Consequently, many questions have arisen concerning the need for such applications, especially when the crop appears to be growing well without them, and since definite responses to Cu, Fe, and Mn have not been documented and responses to Zn and B have been very few

Sulfur Deficiency of Sugar Beets

Sulfur deficiency of sugar beets (Beta Vulgaris L.) was first reported in 1941 by Tolman and Stoker (10) in beets grown for seed in the Willamette Valley of Oregon. The symptoms were described as retarded growth, yellow color, breakdown of leaf tissue, lack of flowering, and increased susceptibility to disease. Since then sulfur deficiency of this crop has been reported in California (11) and Sweden (5). Sulfur deficiency of sugar beets decreases seed yield (10) as well as the yield and percent of sugar in the roots (5). A review of the sulfur requirements of sugar, fiber and oil crops has been published (8)