Ways through which nutrients are lost from the soil
Through the removal of crop residues especially during harvesting e.g beans harvest
Through soil erosion where topsoils with much nutrients are washed away
Through Denitrification process where by nitrogen in the soil is converted into gaseous form and taken back to the atmosphere.
Through leaching i.e downward movement of nutrients to layers where plant roots can not easily reach.
Excessive drainage of land causing nutrient loss in solution
Through burning of vegetative materials that cause loss of nitrogen from the soil
Excessive irrigation leading to leaching of nutrients
Through immobilization i.e build up of nitrogen into microbial tisues during decomposition rendering it unavailable for plant use.
major plant nutrients
Carbon,ydrogen and oxygen
Carbon and oxygen are derived from air through photosynthesis,Hydrogen is got from soil water.
They help in the frmation of cellwalls of plants
They enable plants to carryout photosynthesis being raw materials
Yellow colour between the veins of the leaves
Wilting,drying and finally death of the plant
This is the most important plant nutrient in the soil needed for crops growth and development
Sources of nitrogen in the soil
Nitrogenous artificial fertilizers e.g urea,CAN etc
Application of organic manure/matter
From atmospheric by rhizobia bacteria and free living bacteria(azotobacter)
Ammonification i.e conversion of amino acids into ammonia
Absorption of nitrogen in the soil
It is absorbed by plants in form of Nitrates(NO3–) and ammonium ions(NH4+)