Abstract:

Studies on the productivity of single and double cropping were madeduring the period from 1980 to 1984 on both irrigated and rainfed fieldsin three places of Huang-Huai-Hai plain.The results obtained are asfollows.On irrigated fields of Huang-Huai-Hai Plain and on rainfed areasin the southern part of this plain where rainfall is abundant,the prod-uctivity of double cropping almost doubled that of single cropping,andthe economical income,energy’s efficiency increased remarkably as well.The removal of nutrien...