부산대학교 도서관

Grain planting in Songjiang County in the suburbs of Shanghai Municipality is basically the triple cropping system; namely, planting barley, naked-barley or wheat in winter, planting early maturing rice in the second year [i.e., spring of the following year] after harvesting the winter crop, and then planting late rice as the third crop. With the triple cropping system, approximately 1,400 >u>jin>/u> per >u>mu>/u> [10.5 tons per ha] of grain is produced each year. Production has remained at this level over the past few years. The problems associated with the triple cropping system, such as limits of the growing seasons, labor bottlenecks and intensity, increase in production costs, shortage of fertilizers, decrease in soil fertility, etc., are becoming more and more severe. From cadres to the masses, everybody has his own personal reaction to this matter.