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A list of unfavorable or difficult soil conditions for soil nailing can include dry, poorly graded cohesion-less soils, soils with a high groundwater table, soils with cobbles and boulders, soft to very soft fine-grained soils, highly corrosive soils, weathered rock with unfavorable weakness planes, and loess.
Early invasion of shrub is slow, but once a few bushes have become established, birds invade the area and help disperse scrub seeds. This results in dense scrub growth shading the soil and making conditions unfavorable for the growth of herbs, which then begin to migrate. The soil formation continues and its moisture content increases.
Under saline conditions, the many ions in the soil solution counteract the swelling of the soil, so that saline soils usually do not have unfavorable physical properties. Alkaline soils, in principle, are not saline since the alkalinity problem is worse as the salinity is less.
However, these nematodes can persist in very adverse soil environmental conditions (decreases in nutrients, low moisture contents and temperature) in the J4 or pre-adult stage. [ 11 ] [ 10 ] Paratylenchus spp. have been shown to cause more damage in host root tissue when temperatures are around 20 °C and they prefer levels of pH around 6.5 for ...
However, if conditions are unfavorable, the nematodes can halt their lifecycle. [13] The lifespan of stem and bulb nematodes is about 70 days. [14] Most generations are passed inside bulbs, stems, and leaves. [13] Eggs and larvae overwinter in dried infected host material. [15] They are also found in weed hosts and seeds of composite. [16]
In urban areas decline is aggravated by soil compaction or disturbance, soil pollution (caused by discarded cigarettes, pet droppings, careless or malicious use of herbicides, and road salt), air pollution and unfavorable moisture conditions. In rural areas, maple decline is often attributed to soil acidification caused by acid rain. [1]
Like many wetland plants, it can survive unfavorable conditions as buried seeds in the soil. [9] In a 36-year study on this species in a sinkhole pond, it was found to have an inverse relationship with American Lotus (Nelumbo lutea), declining in years with high American lotus abundance and increasing in years in with low American lotus ...
About 1,000 soil subgroups are defined in the United States. [6] A soil family category is a group of soils within a subgroup and describes the physical and chemical properties which affect the response of soil to agricultural management and engineering applications. The principal characteristics used to differentiate soil families include ...