TROPICAL SOILS — PENDLETON 451 



rice plants transplanted into the standing water and underlying mud. 

 Unfortunately, over much of the kingdom the rainfall is inadequate 

 to raise a crop of rice without some additional water either from 

 streams or from higher slopes nearby. 



Where the forest soils are too poor to be worth planting, and only 

 the termite heaps are cleared, the farmers may go some miles to the 

 steep slopes of the few hills in the region, kaingin the slopes (cut down 

 the trees, burn them) and plant the cotton or upland rice among the 

 stones on the shallow soil, where there are still sufficient plant nutrients 

 in the surface soil from the weathering rocks to grow a crop. Because 

 of the soil limitations rice is produced on about 90 percent of the culti- 

 vated land of the kingdom. By assisting inundation, irrigation in a 

 large way has been applied to some of the soils of the Bangkok plain, 

 but as a whole, conventional effective irrigation by direct flow from 

 large canals is only now being developed. In the northern valleys, 

 farmers cooperatively dig local irrigation ditches to bring onto their 

 fields the water from mountain creeks. 



In some portions of the Bangkok plain the water naturally floods 

 very deeply. These areas require a special type of agriculture using 

 the so-called floating rice. In this case the fields are plowed early, the 

 seed broadcast before the heavy rains and the later deep floods, so that 

 the water as it rises over the plain from the rain and the overflow of 

 the rivers gradually raises the level of the water on the lower land be- 

 tween the rivers. The only danger is that when heavier rains fall 

 earlier in the season the water in the lov^er portions of the plain may 

 rise so rapidly that the plants cannot keep their heads above the 

 water surface, in which case the rice may drown, but where the rice 

 plants survive they may grow to a height of 10 feet or more and pro- 

 duce a fairly good crop. If the flood has not subsided, such a 

 crop may have to be gathered from boats. 



TROPICAL AGRICULTURE 



There are two or three main divisions of this subject that should be 

 considered separately. In the first place, there are the upland subsist- 

 ence crops, that is, crops that are not grown like paddy on flooded 

 fields. The average inhabitant of the Tropics produces most, if not 

 all, of his food by a process called "kaingining," a method that under 

 different names is employed in practically all the humid tropical 

 lowland regions of the world." On the usually poor soils of the 

 humid tropical lowlands the forests are practically the cover crops, 



" This method was described by Cook under the unfortunate name of "milpa." 

 It is often called "shifting cultivation," but this term is not desirable because it 

 implies, and has been described as a means of, food production by nomadic 

 tribes, when in most cases the people who produce food in kaingins live in 

 settled villages and only go out during the crop season to their kaingins. 



