Usually, the term “soil fertility” is used to describe the ability of a soil to provide a good habitat for plants, to sustain agricultural plant growth, and to produce high quality yields. In general, the fertility of a soil is dependent on the quality of the soil itself, and on the presence or absence of biological, physical, and chemical factors. Here, we’ll look at some of the factors involved, including the depth of topsoil, soil humus content, and the presence or absence of inorganic fertilizers.
Biomagnification
Biological magnification is a process in which an organism gathers certain chemical substances. This process may be caused by an organism taking up contaminants from its food, the environment, or a combination of both. The chemicals may be in a concentration much higher than would be found in a non-living environment.
This is the most obvious way of gathering a substance, but there are other more sophisticated processes. Some chemicals are absorbed through the diet of an organism, while others are incorporated into the environment through soil, air, and water.
Biomagnification is an important function of the soil, but it is not without its drawbacks. Anthropogenic activities such as mining and manufacturing release toxic by-products that can be detrimental to the soil. The effects of these activities include soil degradation and depletion of soil biodiversity.
Toxic chemicals are incorporated into the environment through soil, water, air, and other sources. These chemicals are then administered to organisms at different trophic levels through food chains. The concentration of toxic materials increases with each step in the food chain.
One of the most important functions of soil microorganisms is their ability to recycle nutrients, thereby ensuring the soil’s fertility. This can be facilitated by a combination of soil properties such as the presence of heavy metals, clay content, texture, and redox potential.
There are several other important functions of soil microorganisms. Some of the most important are decomposition and biosolids. These processes involve up to 90% of the soil’s energy flux.
Soil contamination can seriously affect crop productivity and biodiversity. It is necessary to control the occurrence of contaminants in the soil to ensure the sustainability of crop production.
Humus content
Several studies have investigated the role of the humus content and soil fertility in the growth of plants. These studies indicate that the concentration of humus depends on the plant yield. It is also important to note that organic matter contributes to the humus content. The organic matter in soil can be classified according to its morphology, chemistry and composition. In addition, the properties of the inoculum and its characteristics affect the growth of bacterial communities.
A long-term experiment was carried out in the Sierra de Gador in Almeria, Spain. The soil was restored by a reclaiming process using municipal solid waste compost. The resulting clay humus complex was effective. The resulting humus content was higher in the amended soil, with a lower TOC.
In a biodynamic treatment, the humus content increased from 2.72% to 3.06%, but the increase was much smaller in the control treatments. This may be due to a reduction in the N emissions from the ploughed layer.
The humus content in the soils that received mineral fertilization was not changed. However, the C and N content of the soil increased. The annual average humus content was increased to 800 kg per ha.
The HA/FA ratio increased with the addition of compost. However, the humic acid to fulvic acid ratio decreased. The depletion of the lipid fraction occurred with time. The changes in the soil lipid fractions were related to the carbon preference index.
Various organic amendments were used to increase the humus content. They included compost from domestic organic waste and sewage sludge. The application of these amendments increased the total amount of organic carbon to a depth of 60 cm. The total amount of organic carbon in the treated soils was calculated to 160 tons per ha.
Inorganic fertilizers
Integrated use of organic and inorganic fertilizers has been shown to improve soil fertility and crop yields in Ethiopia. It also increases the quality of agricultural crops. In addition, it helps protect the soil from erosion.
Organic fertilizers, which are made from plant or animal-based sources, improve the structure of the soil and promote the growth of soil microbes. They also increase the organic matter in the soil and enhance the water retention capacity. Unlike inorganic fertilizers, organic fertilizers release nutrients slowly, improving the texture and composition of the soil.
Inorganic fertilizers are a highly concentrated source of nutrients. Their high nutrient concentration can cause toxicity if a plant is exposed to them. Inorganic fertilizers can also disrupt the balance of the soil’s physicochemical properties.
Unlike organic fertilizers, inorganic fertilizers are manufactured. They are in water-soluble form, which makes them easily accessible to plants. They also contain all the nutrients needed by plants. However, inorganic fertilizers are expensive and can release greenhouse gases.
Soil fertility is a major constraint for agricultural productivity in Ethiopia. The main problem is soil nutrient depletion due to leaching, erosion, and improper nutrient management. In order to maintain agricultural productivity, it is necessary to implement integrated plant nutrition systems that optimize the use of all available sources of plant nutrients.
The soil nutrient status of the soil is limited by the amount of fertilizer that is used and the amount of nutrient that is lost through leaching. A long-term field experiment was conducted at Luancheng Ecosystem Station, NCP. Three fertilization treatments were evaluated: urea (urine), blood meal, and chicken dung.
Compared with the control treatment, the plots receiving the long-term NPK fertilizer had better maize grain yields. In addition, the plots that received the mixed fertilizer treatment had higher maize yields than the control.
Erosion
Various factors can lead to land degradation. These may include loss of vegetation, acidification, depletion of soil organic matter and soil erosion. Land degradation may also include loss of biodiversity.
Soil erosion is a natural process that occurs when particles from the soil surface are carried away by wind or floods. When soil particles are removed from a slope, the soil is exposed to more intense rainfall.
Soil erosion may be caused by a variety of factors, such as wind, flooding, construction activities and grazing animals. Land management techniques such as mulching, cover cropping, contour farming, and strip cropping can help control erosion.
The rate of soil erosion varies according to the type of land use and the topography of the landscape. Intensive farming on steep slopes causes soil loss and soil degradation.
The rates of erosion in Nepal were calculated for three important river basins. The rates ranged from zero in lowland paddy fields to 420 t ha-1 year-1 in shrub lands.
Soil erosion is a major concern for land managers. The amount of soil lost from a landscape can affect the amount of crop production and water holding capacity of the soil. It can also affect the sustainability of farming systems.
Soil fertility is essential for the perfect growing medium. If there are inadequate inputs of fertilizers, plant growth may be inhibited. The soil can also lose its natural humus and microorganisms. Poor quality soil can lead to migration of beneficial soil microorganisms, which may cause a decline in the overall crop production.
Soil erosion has been worsened by the increase in agricultural practices and land use management. Agricultural practices, such as tillage and grazing, remove vegetation from land and compact soil, which reduces soil’s nutrient holding capacity.