Entisols

A study was conducted to investigate the heavy metal contamination of soil and vegetation in the vicinity of industries around Dhaka city in Bangladesh. Categorically soils, grass (Cynoden doctylon L), water hyacinth (Eichhornia crassipes L), rice (Oryza sative L), and arum (Alocasia esculenta L) were collected from tannery, ceramic, textile dying and sulphuric acid producing industrial sites. The concentrations of

Soil sampling to the depth of plant root growth is an effective practice that may reduce fertilizer applications and the potential for leaching loss to groundwater. The objective of this study was to compare the utility of a power auger with traditional core sampling techniques for sampling soils for NO 3 − -N. Since the practical use of NO 3 − -N sampling is to help determine future fertilizer needs, the two methods were compared in production fields with known differentials in N applications. The sampling methods were compared on four soil types : Thurman fine sand (sandy, mixed, mesic Udorthentic Haplustolls), Boelus fine sand (sandy over loamy, mixed, mesic Udic Haplustolls), Hord-Hobbs silt loam (fine-silty, mixed, mesic Cumulic Haplustolls-fine-silty, mixed, nonacid, mesic Molic ustifluvents) and a Crofton-Nora silt loam (fine-silty, mixed [calcareous], mesic Typic Ustorthents-fine-silty, mixed, mesic udic Haplustolls) (...)

In many parts of the world, boron (B) levels are insufficient for potential production. Boron deficiency is also widespread in the Anatolia region of Turkey. Boron deficiency could impact production and quality of tomatoes (Lycopersicon esculentum L.), pepper (Capsicum annum L.), and cucumber (Cucumis sativus L.). A two-year greenhouse experiment was conducted to study yield and quality response of three vegetables to B addition (0, 1, 2, 3, and 4 kg B ha−1). The optimum economic B rates (OEBR) were 2.3, 2.6, 2.4 kg B ha−1, resulting in soil B concentrations of 0.33, 0.34 and 0.42 mg kg−1. Independent of plant species, B application decreased tissue nitrogen (N), calcium (Ca), and magnesium (Mg) but increased tissue phosphorus (P), potassium (K), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentrations. We conclude that a B addition of 2.5 kg ha−1 is sufficient to elevate soil B levels to nondeficient levels. Similar studies with different soils and initial soil-test B l...

ABSTRACT We studied the effects of Pb pollution on soil dehydrogenase and phosphatase activity. Samples of four soils (Saxe, Podest, Porto Teulada, and Sa Xia Manna) were collected from various locations in southwestern Sardinia, Italy. The soils, which differ mainly in heavy metal contents of pedologic origin (Cu, Zn, Cd, and Pb), were treated with Pb (0, 100, 500, 1000, and 5000 g Pb g-1 soil) and incubated in the laboratory. Samples of the incubated soils were collected periodically (0, 1, 2, 4, 8, and 16 weeks) and the enzymes were measured. Soil dehydrogenase activity was influenced by both the Pb additions and variations in soil moisture content. Only the addition of 5000 g Pb g-1 soil led to a significant decrease in dehydrogenase activity compared to the controls, while the other doses of Pb did not always result in a clear reduction in enzyme activity. Drying the soil led to a considerable reduction in dehydrogenase activity, sometimes so far as to render the differences found between the various treatments not statistically significant. Soil phosphate activity was also influenced by the Pb additions, but the effect of the variation in soil moisture content was less than that found for the dehydrogenase. After the 2nd week of incubation, the phosphate activity in the Podest and Saxe soils had decreased proportionally to the increase in Pb content. At the end of the incubation period, in the Porto Teulada and Sa Xia Manna soils, a net reduction in phosphatase activity versus controls was found only at the highest Pb concentration. Although both enzyme activities were influenced by the Pb additions, the phosphate activity was less sensitive to variations in the soil moisture content and may thus be a more suitable indicator for soil pollution by Pb.

Five cultivation implements (two flex-tine cultivators, brush hoe, and rolling and shovel cultivators) were evaluated for weed control and effect on broccoli, snap bean, and sweet corn yield. Each implement was used alone or in combination with flex-tine cultivators. Standard broadcast herbicide treatments were: broccoli, metolachlor at 2.3 kg ai/ha posttransplant; snap bean, metolachlor preemergence (PRE) at 2.3 kg ai/ha followed by fomesafen postemergence (POST) at 0.4 kg ai/ha; sweet corn, atrazine at 1.1 kg ai/ha plus metolachlor at 2.3 kg ai/ha PRE. In the snap bean trials, an additional treatment consisted of metolachlor at 2.3 kg ai/ha PRE applied in a 25-cm band over the crop row followed by fomesafen POST at 0.4 kg ai/ha directed at the crop row, with a subsequent shovel cultivation. In the sweet corn trials, all cultivation treatments received an application of atrazine at 1.1 kg ai/ha plus metolachlor at 2.3 kg ai/ha PRE in a 25-cm band over the crop row. In broccoli, wee...