VIII. 



35 y MAIZE 



CHAP. South African soils are frequently deficient in humus, and 



where this is the case organic matter must be added if good 

 crops are to be obtained. This may be clone by manuring 

 with farmyard manure (If 309J, or by ploughing into the soil 

 some "green-manure " crop. 



313. Use of Leguminose Green-manure Crops. — On sandy 

 soils a leguminose crop, such as soybeans, velvet beans, 

 cowpeas, or kaffir beans, proves very beneficial to the maize 

 crop following. A greater yield of maize may be obtained on 

 a poor, sandy soil from the use of a crop of this character, 

 with the addition of a phosphatic fertilizer, than would be 

 secured in two years where maize is grown continuously {Watt, 

 R. £>., 2). 



To the South African farmer a particularly important feat- 

 ure of crop rotation is the possibility it furnishes of adding 

 humus (it 312) to the soil by ploughing in a growing crop, 

 usually a legume, which at the same time adds one of the 

 most expensive elements of plant-food, namely nitrogen, to 

 the soil. The leguminose crop in the rotation (IT 31 1 and 

 314) is often treated in this way, but a crop of any kind of 

 green weeds may also be ploughed in to advantage, where 

 humus only is wanted, and this may be done when the land 

 is in summer fallow. 



Hopkins (5, p. 199) definitely states that the most import- 

 ant, and least appreciated, method of maintaining or increasing 

 the supply of organic matter in the soil is by the use of green 

 manures and crop residues. A ton of clover ploughed under 

 will add nearly three times as much organic matter to the soil 

 as can possibly be recovered in the manure if the clover is fed ; 

 but with maize only one-tenth of the dry matter of the crop is 

 found in the manure. 



314. Rotations with Maize in other Countries. — A look at 

 a few rotations practised elsewhere may be instructive. One 

 in use in the Northern United States is : — 



First year . . Wheat or rye. 



Second year . . . Clover or grass. 



Third year . . . Maize with farmyard manure, and with 



winter rye sown at the last weeding to 

 furnish late pasture and winter feed. 



Fourth year . . . Oats. 



