After the rice has been transplanted its care, unlike that of our wheat crop, does not cease. It must be hoed, fertilized and watered. To facilitate the watering all fields have been leveled, canals, ditches and drains provided, and to aid in fertilizing and hoeing, the setting has been in rows and in hills in the row.
The first working of the rice fields after the transplanting, as we saw it in Japan, consisted in spading between the hills with a four-tined hoe, apparently more for loosening the soil and aeration than for killing weeds. After this treatment the field was gone over again in the manner seen in Fig. 166, where the man is using his bare hands to smooth and level the stirred soil, taking care to eradicate every weed, burying them beneath the mud, and to straighten each hill of rice as it is passed. Sometimes the fingers are armed with bamboo claws to facilitate the weeding. Machinery in the form of revolving hand cultivators is recently coming into use in Japan, and two men using these are seen in Fig. 14. In these cultivators the teeth are mounted on an axle so as to revolve as the cultivator is pushed along the row.
Fertilization for the rice crop receives the greatest attention everywhere by these three nations and in no direction more than in maintaining the store of organic matter in the soil. The pink clover, to which reference has been made, Figs. 99 and 100, is extensively sowed after a crop of rice is harvested in the fall and comes into full bloom, ready to cut for compost or to turn under directly when the rice fields are plowed. Eighteen to twenty tons of this green clover are produced per acre, and in Japan this is usually applied to about three acres, the stubble and roots serving for the field producing the clover, thus giving a dressing of six to seven tons of green manure per acre, carrying not less than 37 pounds of potassium; 5 pounds of phosphorus, and 58 pounds of nitrogen.
Where the families are large and the holdings small, so they cannot spare room to grow the green manure crop, it is gathered on the mountain, weed and hill lands, or it may be cut in the canals. On our boat trip west from Soochow the last of May, many boats were passed carrying tons of the long green ribbon-like grass, cut and gathered from the bottom of the canal. To cut this grass men were working to their armpits in the water of the canal, using a crescent-shaped knife mounted like an anchor from the end of a 16-foot bamboo handle. This was shoved forward along the bottom of the canal and then drawn backward, cutting the grass, which rose to the surface where it was gathered upon the boats. Or material for green manure may be cut on grave, mountain or hill lands, as described under Fig. 115.
The straw of rice and other grain and the stems of any plant not usable as fuel may also be worked into the mud of rice fields, as may the chaff which is often scattered upon the water after the rice is transplanted, as in Fig. 168.