1.2.3 Soil pollution from agricultural wastes
pressure of population growth requires increased food demand, food growing and to enhance the exploitation of soil fertility by several measures: Increase the use of chemical inorganic substances such as fertilizers, pesticides, herbicides, use of growth stimulants reduce losses and generate resources for harvesting, expanding irrigation systems.
However, in fertilizers and pesticides animals (PPD) is often available heavy metals and persistent substances, when accumulated to a certain limit, they will become pollutants.
- Compared to countries with modern agriculture in the world, the amount of classification of our country is still low, but it is a cause of pollution of land, water is due to:
+ Efficient fertilizer use in our country is still low: Dam reaches 30-45%, 40-45% Lan, Kali 40 -50%. Distribution losses amount is 1455.1 thousand tons in 2007 (814,5.103 tonnes N, 330,7.103 tons P, K 309,9.103 tons).
+ Irregular Fertilization: Fertilizer too much in too little plain and in midland and mountainous. The amount of fertilizer depends on the economic conditions of each household.
+ Improper techniques Fertilization: Fertilizer was applied primarily on the ground, the field so easily lost. If buried fertilizer will increase fertilizer efficiency reaches 70-80%.
+ Unbalanced Fertilizing: Most farmers are using too much fertilizer to fertilize crops, while P and K are low. The rate of fertilizer N, P, K imbalance seriously (10: 3: 1), the ratio of the world is 10: 4: 3 (2003) of K used in our country is very low. The unbalanced fertilizer will reduce the efficiency of fertilizers for plants and adversely affect soil quality.
+ Quality fertilizer does not guarantee: Many fertilizers contain itself toxic substances:
for example: The distribution of impurities in superphophat
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