Large overwinter losses of fall‐applied fertilizer N from midwestern U.S. soils occur through lea... more Large overwinter losses of fall‐applied fertilizer N from midwestern U.S. soils occur through leaching and denitrification. These losses result in decreased efficiency in the utilization of applied N and often in lower crop yields. Of the various management techniques available to reduce N losses, previous studies with spring‐applied N suggested that inhibiting nitrification of applied ammonium with specific chemicals appears to be most compatible with current fertilization and crop production practices. We tested the effectiveness of a specific nitrification inhibitor, 2‐chloro‐6‐(trichloromethyl)pyridine (nitrapyrin), in reducing losses of fall‐applied N by comparing the growth, disease incidence, and yield of corn growing in field plots receiving anhydrous ammonia with those treated with anhydrous ammonia containing the inhibitor.Three field experiments on two soil types (Typic Argivdoll coarse‐loamy, mixed mesic and Vertic Halpla‐quoll fine, montmorillonitic, mesic) demonstrated...
... that swine manure is an excellent organic fertilizer for corn (Zea mays L.) when applied at a... more ... that swine manure is an excellent organic fertilizer for corn (Zea mays L.) when applied at appropriate rates (Kornegay et al., 1976; Evans et al., 1977; Sutton et al ... Addition of ni-trapyrin at rates of 25 or 50 mg Ll of swine manure applied to soil at a rate of 110 Mg ha-', had no sig-...
Plant nutrition, although frequently unrecognized, has always been an important component of dise... more Plant nutrition, although frequently unrecognized, has always been an important component of disease control. The effects on disease of crop rotation, crop sequence, liming for pH adjustment, irrigation, and organic amendments such as manure are frequently through nutritional interactions as much as other factors. These practices supply nutrients directly, or render them more or less readily available for plant uptake through altered solubility or modified microbial activity. The effect of microbial activity and environment also may obscure the role of a specific element. The generally adequate availability of most nutrients for plant growth has induced an apathetic attitude toward the vital role of minerals in disease resistance. This is especially true for Mn which, although recognized as an essential element, has received most attention because of its potential toxicity.
... Most of the evidence supporting the re-lationship between the Mn status of the plant and ... ... more ... Most of the evidence supporting the re-lationship between the Mn status of the plant and ... Bimessite was chosen because it is a common Mn oxide mineral in soils (15) and ... Pages 31-50 in:Biomineralization Processes of Iron and Manganese: Modern and Ancient Environments. ...
ABSTRACT Glutamine synthetase and glutamte dehydrogenase activity, free ammonia, and changes in f... more ABSTRACT Glutamine synthetase and glutamte dehydrogenase activity, free ammonia, and changes in free amino acid pools in tissue of three maize genotypes differing in enzyme activity were measured after 0, 2, 6, 12, and 24 hour incubation with 1 mM methionine sulfoximine (MSX) and 10 mM NH4+ in nutrient solution. Glutamine synthetase activity was almost nil in roots and decreased about 80 percent in shoots after six hr incubation with MSX. Glutamate dehydrogenase activity was not affected by MSX, but was very low in tissue of the ‐GDH maize mutant. In general, total amino acids decreased with time in MSX. Glutamate in root tissues of the Illinois N6 wild type decreased 80 percent after 24 hr incubation with MSX while it was reduced only 60 percent in the Illinois N6 mutant.
Large overwinter losses of fall‐applied fertilizer N from midwestern U.S. soils occur through lea... more Large overwinter losses of fall‐applied fertilizer N from midwestern U.S. soils occur through leaching and denitrification. These losses result in decreased efficiency in the utilization of applied N and often in lower crop yields. Of the various management techniques available to reduce N losses, previous studies with spring‐applied N suggested that inhibiting nitrification of applied ammonium with specific chemicals appears to be most compatible with current fertilization and crop production practices. We tested the effectiveness of a specific nitrification inhibitor, 2‐chloro‐6‐(trichloromethyl)pyridine (nitrapyrin), in reducing losses of fall‐applied N by comparing the growth, disease incidence, and yield of corn growing in field plots receiving anhydrous ammonia with those treated with anhydrous ammonia containing the inhibitor.Three field experiments on two soil types (Typic Argivdoll coarse‐loamy, mixed mesic and Vertic Halpla‐quoll fine, montmorillonitic, mesic) demonstrated...
... that swine manure is an excellent organic fertilizer for corn (Zea mays L.) when applied at a... more ... that swine manure is an excellent organic fertilizer for corn (Zea mays L.) when applied at appropriate rates (Kornegay et al., 1976; Evans et al., 1977; Sutton et al ... Addition of ni-trapyrin at rates of 25 or 50 mg Ll of swine manure applied to soil at a rate of 110 Mg ha-', had no sig-...
Plant nutrition, although frequently unrecognized, has always been an important component of dise... more Plant nutrition, although frequently unrecognized, has always been an important component of disease control. The effects on disease of crop rotation, crop sequence, liming for pH adjustment, irrigation, and organic amendments such as manure are frequently through nutritional interactions as much as other factors. These practices supply nutrients directly, or render them more or less readily available for plant uptake through altered solubility or modified microbial activity. The effect of microbial activity and environment also may obscure the role of a specific element. The generally adequate availability of most nutrients for plant growth has induced an apathetic attitude toward the vital role of minerals in disease resistance. This is especially true for Mn which, although recognized as an essential element, has received most attention because of its potential toxicity.
... Most of the evidence supporting the re-lationship between the Mn status of the plant and ... ... more ... Most of the evidence supporting the re-lationship between the Mn status of the plant and ... Bimessite was chosen because it is a common Mn oxide mineral in soils (15) and ... Pages 31-50 in:Biomineralization Processes of Iron and Manganese: Modern and Ancient Environments. ...
ABSTRACT Glutamine synthetase and glutamte dehydrogenase activity, free ammonia, and changes in f... more ABSTRACT Glutamine synthetase and glutamte dehydrogenase activity, free ammonia, and changes in free amino acid pools in tissue of three maize genotypes differing in enzyme activity were measured after 0, 2, 6, 12, and 24 hour incubation with 1 mM methionine sulfoximine (MSX) and 10 mM NH4+ in nutrient solution. Glutamine synthetase activity was almost nil in roots and decreased about 80 percent in shoots after six hr incubation with MSX. Glutamate dehydrogenase activity was not affected by MSX, but was very low in tissue of the ‐GDH maize mutant. In general, total amino acids decreased with time in MSX. Glutamate in root tissues of the Illinois N6 wild type decreased 80 percent after 24 hr incubation with MSX while it was reduced only 60 percent in the Illinois N6 mutant.
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