questions: asking about the method for soil testing 
 answers: advised him to collect at least 15-20 random samples in "v" shaped by spade or how from the plot and then collect the soil into one place, divide it into 4 parts  and discard the corresponding 2 parts till it becomes 500 gm. then take this 500 gm soil sample into one plythene bag and put a lable mentioning name of collector, place of collection, date of collection, cultivation history of the field etc and send it for testing.