Tag: improved methods of agriculture

Neem oil is mainly used to prevent the pests at home. Neem leaves help in stopping the growth of pests. It kills larvae and locusts at homes. Mosquitos die when neem extract is sprayed.

The grains are stored in huge stores and warehouses. These stores and warehouses should be regularly and strictly cleaned, disinfected and kept dry to avoid ants, insects, worms or rodents infestations and keep the grains safe and hygienic for consumption at any time. There should be proper space or be disjoining between the grain sacks for fumigation and regular inspection of the grains The grains are stored in mass scale in huge chambers called silos. the silos have a proper outlet to withdraw the desired quantity of grains.The silos have built-in arrangements for aeration, fumigation, protection from rodents, insects and bird etc. Thus all three options strict cleaning, proper disjoining and fumigation is equally important for the storage of grains.

If the freshly harvested grains are not dried, it might contain moisture and moisture provide growth media for various organisms like molds. Drying will delay the spoilage of the grains.
Thus, the correct answer is option A.

Aspergillus consists of several hundred mould species found in various climates worldwide. Aspergillus is highly aerobic and are found in almost all oxygen rich environments. The storage grain produces aflatoxin due to growth of Aspergillus which can cause acute liver damage and cancer.

Fertilizer burn can occur when too much fertilizer is applied resulting in drying out of the leaves, damage or even death of the plant.

Nitrogenous fertilizers leach away from the soil easily due to their high solubility in water and pollute the water bodies. Nitrogen leaching is a naturally occurring process, it occurs when nitrogen leaves the soil in drainage water. Nitrate is soluble and mobile. It is no problem when it is within the root-zone, but once it gets into the groundwater and other freshwater bodies it is an environmental pollutant.

Nitrogen has to be converted to nitrate, in order to be used by plants. Hence, using nitrate fertilizers directly would be the quickest way to provide nitrogen to the plants. Ammonium nitrate is an important fertilizer with the NPK-rating 34-0-0 (34% nitrogen). It is less concentrated than urea (46-0-0), giving ammonium nitrate a slight transportation disadvantage. Ammonium nitrate's advantage over urea is that it is more stable and does not rapidly lose nitrogen to the atmosphere. During warm weather it is best to apply urea soon before rain is expected or to cover it with soil to minimize nitrogen loss. 

All plants require sufficient supplies of macronutrients for healthy growth, and nitrogen (N) is a nutrient that is commonly in limited supply. Nitrogen deficiency in plants can occur when organic matter with high carbon content, such as sawdust, is added to soil. Soil organisms use any nitrogen to break down carbon sources, making N unavailable to plants. This is known as "robbing" the soil of nitrogen. All vegetables apart from nitrogen fixing legumes are prone to this disorder.

Some symptoms of nitrogen deficiency (in absence or low supply) are given below:

1. The chlorophyll content of the plant leaves is reduced which results in pale yellow colour. Older leaves turn completely yellow.
2. Flowering, fruitings, protein and starch contents are reduced. Reduction in protein results in stunted growth and dormant lateral buds

NPK $:$ The elemental shorthand for the three major nutrients in fertilizers. “N” stands for Nitrogen, “P” stands for Phosphate (${ P } _{ 2 }{ O } _{ 2 }$) and “K” stands for Potash ($\\ { K } _{ 2 }O$). These are the chemical forms of nitrogen, phosphorus and potassium that are present in fertilizers.

Biomagnification stands for Biological Magnification, which means the increase of contaminated substances or toxic chemicals that take place in the food chains. These substances often arise from intoxicated or contaminated environments. The contaminants include heavy metals namely mercury, arsenic, fertilizers&pesticides such as DDT, and polychlorinated biphenyls (PCBs) compounds which are then taken up by organisms because of the food they consume or the intoxication of their environment.