(a) State three ways in which science and technology have contributed to agricultural 
development through each of the following: 
              (i)           Crop protection; 
              (ii)          Climatology and meteorology.                             [6 marks] 
(b) Give two functions of each of the following farm machines and implements: 
              (i)           bulldozer; 
              (ii)          combine harvester; 
              (iii)         tractor; 
              (iv)         sprayer;

                (v)           planter. -                                                      [10 marks]

(a) In a tabular form, list ten differences between subsistence agriculture and commercial agriculture. [10marks]
(b) State one advantage and one disadvantage of the following sources of farm power: 
                (i)           wind; 
                (ii)          internal combustion engine; 
                (iii)         electricity. [6 marks]

(a) What is soil consistency? 

(b) Explain how each of the following soil properties influences crop growth: 
          (i)        soil texture; [2 marks] 
(ii) soil pH. [4 marks]

(c) (i) List four methods by which soil fertility could be maintained. [2 marks] 
(ii) Explain two ways in which each of the methods listed in 3(c)(i) contributes 
to the maintenance of soil fertility. [8 marks] 

(a) (i) Define the term soil tillage. [2 marks] 
(ii) Distinguish between primary tillage and secondary tillage. [2 marks] 

(b) Outline three roles of each of the following soil management practices: 
(i) Green manuring; 
(ii) Mulching. [6 marks] 

(c) Give six reasons for carrying out irrigation in crop production. [6 marks]

(a)(i) Define vegetative propagation. [2 marks] 
(ii) Give three advantages and three disadvantages of vegetative propagation. [6 marks] 

(b) State four cultural methods used for controlling crop pests in the field. [4 marks] 

(c) Enumerate four harmful effects of chemical pest control. [4 marks]