The lower leaves turn yellow and in some crops they quickly start drying up as if suffering from shortage of water, stunted growth, leaves & fruits shedding & whole plant becomes yellow, are deficiency symptoms of:_________?

The lower leaves turn yellow and in some crops they quickly start drying up as if suffering from shortage of water, stunted growth, leaves & fruits shedding & whole plant becomes yellow, are deficiency symptoms of:_________?

A. Potash
B. Nitrogen
C. Calcium
D. Both a & c

From the sources of plant nutrients availability in soil, which of the following statements are correct:

From the sources of plant nutrients availability in soil, which of the following statements are correct:

A. The plant absorbs carbon as carbondioxides directly from the atmosphere.
B. Water is the source of hydrogen
C. Air & water is the source of oxygen & the chief source of soil nitrogen is organic matter & when organic matter decomposes it gives ammonia.
D. All of the above