Soil poorly drained

PRZM was applied to a hypothetical situation of a pesticide In a Georgia agricultural environment. An overall, pseudo-first-order degradation rate coefficient of 0.001 day was used, along with a series of values. A cover crop of peanuts was assumed. The simulation was done for a 900 g/ha application to a class A soil (well drained) and a class D soil (poorly drained). Movement through the root zone was simulated using rainfall records. In the hypothetical 1-ha plot, 800 g and 550 g of the pesticide leached past 60 cm In the class A and D soils, respectively, when a Kj value of 0.06 was used 40 g and 5 g leached past 60 cm In the class A and D soils, respectively, when a Kj value of 1.5 was used. These computational results support the conclusion on Kj values stated at the end of this paper. 

Paddy soils are managed for the purpose of growing rice. Rice is grown in flooded soils, poorly drained soils, and well-drained soils. In this section, we primarily discuss the flooded paddy soils (lowland) used for rice production. Management practices imposed on paddy soils include... 

Smectite is the first secondary mineral to form upon rock weathering in the semi-arid to sub-humid tropics. Smectite clay retains most of the ions, notably Ca2+ and Mg2+, released from weathering primary silicates. Iron, present as Fe2+ in primary minerals, is preserved in the smectite crystal lattice as Fe3+. The smectites become unstable as weathering proceeds and basic cations and silica are removed by leaching. Fe3+-compounds however remain in the soil, lending it a reddish color aluminum is retained in kaolinite and A1-oxides. Leached soil components accumulate at poorly drained, lower terrain positions where they precipitate and form new smectitic clays that remain stable as long as the pH is above neutral. Additional circumstances for the dominance of clays are ... 

Rosellinia. Among cacao root rots, that caused by the Rosellinia fungus is a sporadic disease that occurs mainly in poorly drained soils. 

The subsoil at greater depths may be aerobic in well-drained soils with a perched water table owing to an impermeable layer—such as the traffic pan in ricefields or anaerobic in soils fhaf are poorly drained fhroughouf. If may provide significanf quantifies of nufrienfs to planfs growing in the soil if their roots can reach them. 

Though large concentrations of Se can develop in poorly drained soils as a result of accumulation of insoluble Se compounds, Se is also lost under... 

I Manganese deficiency (on potato leaves), common in, poorly drained soil. 

Susceptible plants Apple, pear, hawthorn, and poplar. Some apples, such as Cox s Orange Pippin, Elstar and Gala, are particularly susceptible. More resistant apples include Bramley s Seedling, Lane s Prince Albert and Newton Wonder. Canker is a particular problem on wet, poorly drained soil. 

A common disorder of houseplants and other pot-grown plants, in which cases the main cause is overwatering, especially when growth is slow. May also affect plants in the open ground growing in poorly drained soil. 

Wetland Poorly drained, low relief areas in which soils and sediments are seasonally or continuously saturated or covered with water. Wetlands include bogs, swamps, and fens. 

Environmental organic matter is a composite of humic and nonhumic substances, which is formed through operation and interactions of various biotic and abiotic processes. Humic substances are formed through both selected preservation (residue) and catalytic synthesis mechanisms. Both enzymatic and mineral catalyses contribute to the formation of humic substances in the environment. The relative importance of these catalytic reactions would depend on vegetation, microbial population and activity, enzymatic activity, mineralogical composition and surface chemistry of environmental particles, management practices, and environmental conditions. Selective preservation pathways would play a more important role in humification processes in poorly drained soils and lake sediments, compared with more aerated environmental conditions. 

Ametryn, another triazine herbicide, was previously used for weed control in citrus. This herbicide first appeared in recommendations in 1979 for control of broadleaf weeds, annual grasses, and some perennial grasses. Ametryn was recommended at use rates of 3.6-7.2kg a.i./ha, with a maximum of 5.4kg a.i./ha for both shallow, poorly drained flatwood soils (soils having more organic matter and clay) and bedded groves (trees planted on raised beds). It was recommended that ametryn should not be applied to trees less than 2 years old. Between 1984 and 1988 the application rates were increased to 7.2-10.8kg a.i./ha, with the annual rate not to exceed 13.6kg a.i./ha, and with lower rates... 

Features such as mountains and large bodies of water restrict the spread of many pests. Other features of the landscape can have similar effects. Soil type is a prime factor affecting wireworms, grubs, nematodes, and other soil organisms. Some pests live in heavy, poorly drained soil, others in light, sandy soils. Soil type also affects the distribution of plants (including weeds), which in turn affects the population of insects and other plant pests. 

River chemistry is very sensitive to alteration by many human activities, particularly mining and the chemical industries, but also to urbanization as urban wastewaters are much more concentrated than rural streams, and to agriculture through the use of fertilizers (Table 2) (Meybeck et al., 1989 Meybeck, 1996 Flintrop et al., 1996). New sinks are also created such as reservoirs (calcite and silica trapping enhanced evaporation) and irrigated soils, which may retain soluble elements if they are poorly drained. New controls correspond to these anthropogenic influences, such as mining... 

Tree declines stunted pale leaves no new growth. Cause Root rot. Root rot can be caused by overwatering or by poorly drained soil, but the disease may take years to develop. There is no cure. Replant in well-drained soil or on a raised mound of soil. Grande and Martin are rootstocks resistant to this problem. 

Boxwoods prefer a site partially sheltered from winter winds. They will flourish in a range of conditions, from full sun to deep shade, and can adapt to almost any soil (with the exception of poorly drained sites or heavy clays). Set out as balled-and-burlapped or container-grown plants in spring. Set out plants no deeper than they grew in the nursery. A thick layer of mulch will help keep roots cool and retain moisture. Clean up all fallen leaves and remove debris from branch crotches in autumn. 

Leaves yellow and wilting stems blackened at base plant topples over. Cause Stem, root, and crown rots. These problems are common when bellflowers are kept overly wet or are grown in poorly drained soil. The base of an infected plant may show grayish white mold dark lesions blacken the stem from the soil up. eventually girdling the plant. Remove and... 

Roots or crowns rotted. Cause Various fungal or bacterial diseases. Root rot is often brought on by soggy, poorly drained soil or pre ious insect damage to the roots. Plant carrots in loose, well-drained soil and keep soil moist, but not soggy. Use raised beds to impro e drainage. 

Plant in spring as balled-and-burlapped or container-grown plants. Although not particular as to soils, avoid poorly drained sites. Cotoneasters do best in full sun. Cotoneasters can withstand wind, dry soil, and even salt spray. 

Set out balled-and-burlapped plants in full sun in early spring. Hawthorns are undemanding as to soil, but avoid poorly drained areas. Choose planting sites with good air circulation to minimize disease problems. To avoid rust diseases, don t plant hawthorns where Eastern red cedar (Juniperus virginiana) is common. 

Stems blacken at base leaves wilt plant falls over. Cause Crown or root rots. Both fungi and bacteria cause crown and root rot of delphiniums. Plants may wilt suddenly or yellow and wilt slowly. Stems and roots may turn black mold may appear. Poorly drained, overly wet soil promotes rot choose well-drained sites and add organic matter to improve drainage. Avoid injury to crowns when digging near plants keep winter mulch away from crowns. Remove and destroy infected plants wash tools used around diseased plants. Solarize the soil before replanting. 

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