稻茬少、免耕小麦吸肥特性研究

少、免耕小麦百公斤籽粒耗氮量较翻耕麦低,在同等产量水平下,植株总吸氮量较少。少耕、免耕小麦前期群体发展快,发根早、吸收氮、磷、钾量比翻耕麦多,这段时期在其一生中,吸肥总量的比例高;但中后期的吸肥量下降。稻茬少耕、免耕后,0-40cm土层的供氮量一直低于翻耕地;但其0-10cm的表土层供氮能力在拔节前相对较高,拔节后下降。因此,少耕、免耕麦应在施足基肥基础上,早施苗肥促早发,重施拔节肥防早衰。

STUDIES ON THE CHARACTERISTICS OF UPTAKE OF FERTILIZER UNDER THE CONDITIONS OF ZERO AND SHALLOW TILLAGE AFTER RICE REAPED IN WINTER WHEAT

The uptakes of N,P,K of winter wheat and the capability of N suppliedof soil under the conditions of zero and shallow tillage after rice reapedwere studied at the experimental centre of Nanjing Agricultural Univer-sity in Shuyang county, Jiansu province during 1985~1987. The principalresults were summed up as follows:Amount of N absorbed per hundred kg.grain yield produced by zero and shallow tilled wheat was lower than that of ordinary tillage(CK).Therefore, the total N absorbed by plant of zero and shallow tilled wheatwas lower also under the condition of same yield. Amount of N suppliedin the soil layer(0-40cm)of zero and shallow tillage was lower than thatof CK in the growth periods of winter wheat.But, the percentage of am-ount of supplied N of upper soil layer(0-10cm)in all soil layer (0-40cm)of zero and shallow tillage was higher than that of CK before jointingstage in winter wheat.The growth at early stage of zero and shallow tilledwheat was fast,which beared more leavies, roots and tillers. Meanwhile,more N,P,K was absorbed in the early stage. Therefore, more fertilizer mustbe applied in the early stage and some N fertilizer whould be used also atjointing stage or later stage in case premature decay.