Tag: soil and its conservations

Soil conservation is the process of prevention of soil erosion and to prevent the soil from becoming infertile.  In mulching, a protective layer is placed over the soil such as straw, grasses etc., which helps in retaining soil moisture and also regulates soil temperature. Strip cropping is a process in which field is divided into strips and different crops are grown in alternate strips to preserve soil fertility. Crop rotation means growing of different types of crops on the same field in succession which prevents the depletion of nutrients from the soil. Overgrazing or intense grazing will erode the soil.

If the same crop is grown year after year, fertility of soil is lost due to utilization of same minerals again and again, thus, disturbing the soil structure, which facilitates soil erosion. Legumes are useful in rotation of crops because of having nodulated roots which harbour nitrogen fixing Rhizobium bacteria and it leaves more nitrates in the soil when the roots are left over in fields and only aerial parts of legume crops are harvested.

Vermicomposting is a method in which earthworms are used to convert the organic wastes into compost, which is a good fertilizer for plants. It increases the soil fertility. Manure is the organic matter mainly animal feces and straw. It adds nutrients (nitrogen) in the soil, which increases the soil fertility. So, the correct option is D.

Soil erosion is removal of top soil by agency of water (water erosion) and wind (wind erosion). One of the methods for soil conservation against soil erosion is terracing. In terracing, slope is divided into a number of flat fields for slowing down the flow of water. Terracing is very effective in hilly areas for control of soil erosion.

Anthropogenic soil erosion is caused by removal of plant cover through over grazing, litter collection, tree felling, leaving the soil unprotected during agricultural operations. Anthropogenic factors remove green cover and expose the soil to natural agents of soil erosion i.e., water and wind. When rains fall, most of the top layer of soil is washed away, if the soil is not covered by vegetation. 

Soil pollution is caused by removal or addition of substances which decrease its productivity. It is caused by agrochemicals, industrial wastes, municipal wastes etc. It adversely affects the fertility of the soil. Pesticides, weedicides, and fertilizers are added to soil in agriculture practices to remove unwanted plants and increase the fertility of the soil. These chemicals penetrate into soil and damages the soil.

• The contamination of soil with solid waste, acid rain excess of fertilizers, Insecticides, and herbicides is called soil pollution.
• Soil pollution can lead to water pollution if toxic chemicals leach(drain away from the soil) into groundwater, or if contaminated runoff reaches streams, lakes, or oceans.
  
• Hence Soil pollution can lead to water pollution is a true statement.
• So, the correct answer is 'True'.

Mulching refers to the covering of harvested field with plant litter or polythene of low density, in order to decrease run off, prevent the growth of weeds and retention of water. It protects the roots from seasonal variations.During initial stages of growth, mulching helps to maintain a stable temperature for proliferation of seedling.