387 research outputs found
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
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
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)
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)
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